Glad to hear your not a meter snob, Clive. Too many folks insist that they would not touch them with a barge pole, even for the most simple 12v tasks. Like you say, it's all about common sense, knowing it's limitations. Certainly good enough for a lot of hobbyist applications.
+100SteveB I keep mine in my car's welly, just in case it's storming out. /badjoke. I keep meaning to pick up a few more since they are so disposable and we don't have any functional meters at work. I hate running into a simple problem where a little info on voltage could solve it, just to be left guessing.
+100SteveB I agree, glad to see Clive saying so. I probably have 10 or more of those Harbor Freight meters. I get one for free whenever they're doing that deal and I go in for anything. I like having a meter in the car, one in each tool bag, one in a desk drawer at work, etc. I've never needed much accuracy - if it'll tell me 30 milliamps or 1000 ohms within 2 or 3 percent, good enough for me. In reality, I've put it up against the best meter I have (Extech) and it's always within 1 least significant digit, tested across 3 or 4 < $5 meters.
If you want to see something explode, watch Big Clive's video with the "TIG welder" and that Chinese "AC/DC LED" he connected directly to line/mains voltage. (Was that posted on April 1st? :-)
Good to see you using "real world" equipment. Certain UA-cam personalities would have people believe that everyone associated with professional electronics has a Fluke meter, Hakko (never seen one used in anger the UK to be honest) soldering station, and multi-Gsample digital scope. The real world is much more like this: A cheap meter that is just sitting around the place and works absolutely perfectly on low voltages, and a Weller iron that you've had for 20 years and never lets you down.
Did you watch his electronics basics video from a few weeks ago? It helps :) I know what you mean though, the more advanced theory is way above my head, yet still I watch!
Gotta love how the little circuit board is in such a shape that it could be inserted and potted inside the base of a lamp. They are very generic drivers but they work, but it seems the designer had originally made them for lamps such as bi-pin MR16 form factor lamps. If you go try and buy replacement drivers some of them even come with the pins soldered on the input side.
I recommend the small 10€ Uni-T meter, its super small, has fixed wires, a very clever position for the fuse (but only 200ma max because of that) and a little signal generator, which is about 75hz. I use it more than the expensive Fluke, because its accurate enough for almost everything.
The original use of these regulators (in that exact form factor) is in LED spots made for direct replacement of halogen spots running on 12V AC. That's why they have the bridge rectifier (and often come with the pins for the halogen socket). If you get them in bulk, they cost maybe 1€/$/£ a piece on ebay. I got quite a few of them and always removed the Schottky diodes (gets the useable voltage range down a volt). For current adjustment I just piggy back another SMD resistor on top of the one already there.
This is actually very interesting, since I've been toying around with the idea of using some of these 12V lights to illuminate the trees in my back yard at night, and then have a small solar array and bank of those 12Ah SLA alarm batteries so they're ~green~ (and I don't have to fuss about with mains voltage which honestly still scares the pie out of me).
thats another reason i like you more than EEVblog, He constantly just says everythings crap if it doesnt cost $400, i dont have that to spend on a hobby where i just break things and make motors spin faster than they should.
Very interesting video. I have one of those meters - the only thing I have found with them is the rotary switch contacts got dirty after a while and I had to open it up and clean them. It did occur to me that, for a Chinese factory, a little regulator circuit might be cheaper than a ceramic wirewound resistor.
I usally get those drivers to change the resistors: at the end, just changing the current sense resistor you can make it to suit your needs (100mA/Rs), and then they work from 10V to 24V... Quite useful actually and more efficient than "big resistor"
I german, there is the therm "Drossel" which is pretty much identical to "choke". Both therms can be used for an inductor, and "choking someone" is "jemanden erdrosseln". Also "coil" and "Spule" work very similary in german and english. In normal use, we call it "Spule". "Induktivität" is the more academic therm, which we tend to use when going into details, meaning non ideal models. "Drossel" is rearly used - I tend to use it, when I don^t care about specific characteristics.
Choke translates fine into Australia, primary used here in reference to a high frequency blocking inductor but sometimes used as a generic term for an inductor (generally larger than smd)
Just watching this now adn can't help but think the sooty skid mark is from a mains power supply driver smoking itself and the whole thing being recycled as a 12volt light :). Those cheapy meters are great for general use. I love them for basic use.
"Choke" is a commonly used term in amateur radio. Most often, it's used to refer to an inductor built by coiling coaxial cable (a multi turn air core inductor) or snapping a ferrite bead/core over it to block common mode radio frequency current from flowing over the outer shield and wreaking havoc. 73 de AF6AS (my callsign)
i have a $70 multimeter from my local auto store. it is cat IV rated at 300v i think. it has decent probes on it. nice big ones. i have had it for two years and i use it daily. Works very well. i have used it on 240v and all was well.
BC, re: glass, perhaps the obvious would be to cut a fresh piece from that pile at the bottom of the garden. Clear all the way to the edge. Cheers, Andy
Typical idle voltage in a vehicle is around 14.2V, maybe a tad less with accessories running, but it will pick back up once the RPMs come up. This also gets worse in the cold where you can reach 14.8-15V. And with a worn battery you can see as low as the nominal 12V with the engine off and accessory power going.
Yep, the charging voltage for lead acid has a negative temperature coefficient, that is the needed voltage goes down when the temp goes up. In below freezing conditions the voltage can be just over 15.
+codemsan Car systems are notorious source of mysterious peaks and voltage fluxuations, so I'd say it's just good if that lamp can handle say 20V ... On the same note.. I have seen Led worklights with 9-36V voltage range. Most likely having similar chip in them.
I like this guy for many reasons, but a main one is that he doesn't wave his junk around in everyone's face by having to have the most expensive Fluke multimeter on display in every video but uses a modest reasonably priced one.
I burnt one of the cheap meters testing a laptop power brick (Shorted straight to mains, good thing I always check them or that would be one dead laptop). I threw it straight to the trash, kept the leads whose wires I had gone to the trouble of replacing, and bought a similar one. I mod them to include a 9/12v barrel connector socket (with a filtering cap) and use that to load the 9v dry cell when it goes dry. I have a goodish one (Supermarket loss leader), which I use sparingly.
The low rated voltage of the electrolytic would be no problem for using the floodlight at 24V. The cap is at the regulated side of the switch-mode regulator parallel to the LED, at least his position at the PCB suggests this.
Hi Clive, do you have a video on how to use a meter like you had in the video? If you don't, would you be able to make one? I don't know a lot about electronics, but I love watching your videos and find them very educational as I'm trying to learn more. You're fantastic at explaining things and are very clear about what you're doing when you are taking electronics apart, plus I love that your videos come across as very genuine as you're passionate about what you're doing. Cheers!
+Markus Bates Many of the little analogue meters are made in the same style. Just some diodes, resistors and a 100uA sensitivity movement. I can recall an old Tandy one that was made like that.
+Markus Bates Before digital meters analog meters were all that there were. You used to be able to buy a little 2x3 inch analog meter for about $5 at many hardware stores, or mail order. Electrical supply companies would give them away as party favors. They fit in your pocket, and believe it or not were designed to measure 600V AC. They were commonly used to measure 110V and 220V with no problems at all. YOu really don't need seven inches of triple insulated plastic to measure line voltage with reasonable safety. I used them for years as throw-away meters. A lot easier to use than a 7-pound Tripplet on the top of a radio tower to check the power on the warning lights.
+l wilton But you will need metal film resistors and other internal parts that are actually rated for >220VAC (600VAC ideally). In those cheap meters, mostly they aren't. I actually had an analogue pocket meter blowing up due to this.
There may be a single diode on top of the board that has the name SSXX (XX= 24,34,54 etc.) The voltage rating of that diode gives a good idea of what voltage it can handle. I bought one of those drivers a few years ago and it worked well with the max voltage i could give it ie, 18V). Functioned with DC as well as AC supply.
+Lucas Solomon Well, around here people put all kinds of superfluous lights all over their lifted trucks. I was considering making a cheap LED headlight out of a 10 watt chip, but the hole for it to fit through was smaller than the chip by itself.
One thing to consider is that the absorption charging voltage of a modern lead acid AGP car battery is 14.4v, and the chargers will have temperature compensation which will increase the voltage still further perhaps as high as 15.5 in extreme weather.
+James Lewis With the slight increase in LED voltage at the higher current that would probably just boost the output by a few watts amply catered for by the extra cooling of the weather. I'm not at my workshop at the moment so I may actually test that arrangement at worst possible voltage scenarios.
+bigclivedotcom Agreed... it's something I had to consider for a solar power system also, since the better microcontroller driven charge controllers will periodically deliberately overcharge the battery bank (depending on the type of battery) to balance it... so you can find that on a nice sunny day it decides to push the voltage up to 15 or a bit more... so stuff connected to that system needs to be able to cope with that.... of course you probably wouldn't be using a floodlight when that's happening.
+rhkips translate Same in my norwegian, french, guatemalan brain :) A choke is the same in english, I think he's confusing metric and imperial, most scientifit people use standard terminology. I don't know the analogy of what a choke does... strangle?
One of the unbranded meters turned up free with an Ebay order for electronic parts, and has proved very useful, and is accurate. I have got an Avo or two, etc and old GPO test equipment bridges, and the accuracy is up to any test I can come up with. We used to make BS test equipment, (to test the standards), and I had previously tested another makers Chinese digital effort and it was dead accurate.
Of course you can do it, come near 10W drive for it with a resistor, but the problem is that these generic LEDs don't hold up well at full current unless you have a very good heatsink. Try running it at 10W (drive, not total) for a few hundred hours. When I did, albeit with a different heatsink, 6 of the 9 LEDs blew out in under a week of continuous run time and the remaining 3 were operating at a fraction of their anticipated wattage. Have you ran any of these lights, with resistor or switching driver either way, for hundreds of hours? I suggest that keeping them at 5W or lower peak drive current is the best alternative to end up with something that has a more reasonable lifespan, or moving to a higher quality extruded heatsink mounted in the floodlight chassis, open at the back with a low RPM fan on it. A Pentium 2 era CPU heatsink would suffice. Naturally that won't be as robust for rough handling or rainy conditions.
Excellent channel Clive (if I may call you that) I wondered if you had any experience of the Kit: Executive power bank. Model PWRIP6SL Capacity 4100mAh. Its supposedly for iphones and iPads. I was 'forced'to buy one recently when I stupidly left home without chargers. £27 pounds worth in a station shop. I have to say it looks good and charged my phone no problem straight out the box. Charged it from my office PC USB and again no apparent problems. Recharged my phone three times without recharge. However after charging I had to try it in my ipad. It gave it some charge but become very, VERY hot. to warum to hold. That worried me. But after recharging it was apparently ok and works fine with the iphone. Comments welcome Hugh
For future reference, a lot of the newer cars tend to charge at around 14,5-15v. A minor detail but would make all the difference in terms of LED smoke production.
+keltickiwi Hmm, I've tested it up to 14.5V with the 3.3 ohm resistor (11 watt dissipation from the LED) But 15V seems really high for a battery charging voltage.
bigclivedotcom I believe many newer vehicles are fitted with silver calcium batteries which have a higher charging tolerance/requirement. However, I Can't say I've heard of the extra voltage causing any issues with accessories.
As far as automotive applications go, Clive, you forgot something; the vehicle's alternator/generator. With the engine running and the alternator being driven by the serpentine belt, you'll see around 14.5 volts, a maximum of 14.8 volts typically. I can't speak for bigger trucks (lorries) but I would presume the principle would be the same but a different voltage.
I was thinking it would be somewhere around that mark. I don't have any experience with larger trucks, only 'civilian' vehicles that operate on 12-14 volts.
Someday I'll study the history of electricity, specifically how different voltages and frequencies became standard in different countries. I'm sort of partial to the 120/240 60Hz system we have in the USA. The higher frequency does help make transformer design a little easier, and center tapping the transformer to provide two different voltages provides a safer voltage for small loads plus the lower current 240 volts for larger loads like air conditioners, stoves, water heaters, etc.
Load balancing can be an issue. Each side of the centre-tap on the transformer should be under the same load, but that is seldom the case in real-world use. If the centre tap is lost then you can get closer to 230 V on the low load side - fire risk. There is no safety advantage to the 115 V system. In theory you could cut down on insulation, to save some money, but you'd pay a lot more in copper for the larger conductors required. So the lower voltage used is mostly a disadvantage, then you have the complexity of different appliances requiring different outlet types rated at the full or half voltage. A higher frequency is better, but 60 Hz isn't that much different to 50 Hz so you don't really get a huge benefit from decreased transformer sizes. Aircraft use 400 Hz to get the transformer weight down. With the ubiquitous multi-voltage / multi-frequency power supplies
+boggisthecat Yes, not many understand load balancing. The house I grew up in suffered periodic low voltage which caused the picture on our vacuum tube TV to shrink. The TV repairman reported this problem. We called the power company and they reported that ALL of the breakers were on the same leg! The house was also built in 1959 when a main breaker wasn't required. This shortcoming nearly caused the house to burn down when one of the bus bars was accidentally shorted while doing some electrical mods. (No, it wasn't me doing the work!) As for insulation, no savings there. It all has to be rated for 600 volts, regardless. Speaking of saving copper ... there was that brief period in time when ALUMIN[I]UM wire was allowed... So many fires ... and lawsuits!
I actually connect cheap chinese meter into mains (~230V) set to 200 or 20 mA and nothing spectacular happened, it's blown (with a bang) the fuse for the amps measure and some resistors inside, but the rest of the functions were just fine, i'm still using it from time to time
It's hard for me to admit it, but those cheapie meters are probably okay for beginners on a budget, and as Clive said, not needing high accuracy, or high-voltage or -current measurements. Though if it were me, and I had to throw a voltmeter at my "younger self," I'd probably give him an old analog Simpson VOM, or maybe a Heathkit VTVM. ;) That black stuff might be one of those "paint & bake" type coatings, where it's literally melted/fused into the glass. Just guessing, though.
Not sure if it would work for enamel on glass, it would also depend on whether the glass was etched, but a stanley blade held so the angle of the sharpened edge is flat on the glass may work, i use this method for cleaning crud from glass. You may want to put the glass on some thin rubber to stop is slipping around
Did you try a drop of brake fluid on that paint? I was thinking a couple of 1 amp diodes would drop about 2v at full current and less as the supply drops, a possible, maybe :-)
+Green Silver Yea, people call me a horder because I hold onto so much because "I'll need it" or I could use it. Funny thing is if I'm prepped for a situation it never happens.
+Proyectos LED It's a shame there's far too many fakes for the uni-t meters. I have a ut139C that works very good and has decent protection. Unless it's guaranteed to be one of the big name brands, I have to open them up and see how well they're built and protected to be comfortable using them.
Could the coating on the glass maybe be two pieces of glass pressed together with a plastic insert? That would work and make it heat, UV and waterproof.
Maybe you can make a home-made current source to sink 900mA. First step would be a Voltage reference (7805 or resistor+zener) with a potiometer to drive a npn transistor sinking the current and with a resistor (1ohm) connected to the base. Of course it's far from perfect but should be better than just a resistor. When proper current is obtained, replace the potentiometer with resistors for better long term reliability and lower cost.
Sure, but this is what a simple resistor does anyway... The advantage of the transistor current source is a much better stability of the current when the voltage raises (vs simple resistor). The power will actually be dissipated in the npn and base resistor so they share it. The base resistor does most of the job if v is 12V and the npn dissipate more as the v raises. The extra cost is not high and you won't need a high power resistor (less that 1W in the 1ohm that can be done with 5 x 4.7ohm 1/4W in theory). To220 npn are not expensive and can be screwed to the box.
I rewired a 240 v Les spot into 12v but it was a messy affair with cutting the board and welding leds in parallel. Could you show us a more straightforward way?
When you said the dissipation at 12V was around 7W, that included the resistors, dissipation in the LED is about 6W or so, at 10V the LED dissipation was right about 2W. Close enough though ;)
3:44 lol I can reference to that. I stuck my meter across the live and the ground pin of the mains without realizing the leads were in the amperage position. Blew a good chunk out of my meter leads.
Clive, I know you've done teardowns of USB battery packs in the past, but PoundWorld have just started stocking one in the UK. Would you be interested in checking it out?
Shouldn't be too much of a hassle to cut your own glass panel if you were really keen on making the whole thing clear. It just wouldn't be tempered glass, but I'm thinking the current glass isn't either.
+omyk22 I did think that. Numpty boy here diagnosed a dead alternator by checking that. The squealing, smell of burning, and the too-hot-to-touch alternator housing were also a bit of a clue, too ;)
hi mate love your videos.is there any chance you can do a video explaining sequence of testing r1 r2 etc there's a lot of videos on UA-cam showing how to do the tests but none explain why these tests are done and what if you get bad results or readings.cheers
The primary purpose of the R1 R2 reading is to determine if the resistance of the supply (live) to ground (earth) is low enough to pass enough current to trip a circuit breaker instantly by actuating its magnetic trip mechanism. This will depend on the current rating and type (A, B, C or D) of breaker due to the C and D breakers being designed to handle much higher inrush currents to things like transformers. If your circuit reading is too high it could be that the cable run is too long or there could be high resistance connections along the circuit. I should make some electrical test videos at some point. It's worth mentioning that if there is an RCD covering the affected circuit then the original purpose of the R1 R2 test is rendered moot since the RCD will trip first in the event of a live to earth fault.
thanks for the reply.im new to testing and want to know exactly why I'm doing a particular test and why iv got a certain reading rather than just writing a figure down after testing.theres a guy called John ward who explains things well on UA-cam.not on a par with you though.cheers mate
yo Dr Clive I just got a 8 pack of these exact lights from eBay to run in conjuction with my ista breeze i500 wind turbine and 6x lead acid batteries would u recommend running each of these of a 1a fuse and would u do a review of the i500. cheers Charlie fae Falkirk.
@bigclivedotcom Can I ask how did you get the 900mA initial estimate? I've got a similar LED lamp with the same regulator circuit and chip (I blew my rectifier diodes up by stupidly plugging it into the mains. Super sparky and magic smoke! =__=), but has a white colour. I've tested it on my power supply, and am getting 15V 0.66A (to get to the ~10W output). Any pointers on how I can get the proper operational voltage and current? The packaging on my lamp didn't have this information (and because I haven't touched this light in over 2 years, the eBay page is gone :( ).
Typical alternator output on a car is supposed to be 13.8-14.2. Not uncommon to see them around 14.5. I have seen regulators go south and cook the battery at 19 volts. One advice i have for people that have a dead battery. Check your charging voltage, you can fry a brand new battery quickly (learned from experience).
I use a similar cheapy meter as a 2nd/backup meter and I was happy with it for what it is until I blew the fuse and when I opened it to replace I found that there wasnt even a fuse holder, the fuse was actually soldered to the pcb. built down to a price is fine, I paid less than 5 quid for it, but seriously thats cost cutting taken too far
+twocvbloke been out for a long time, my portable led worklamp is one of these (put together by me) and a 12v 7ah lead acid, came out before the ones with a lithium pack on them, so about 4 years ago. both portable and charged via cigar lighter as was the need
***** yes the entire package is what i refer to also!, in fact back then i also wanted a 240v ac one, did not find one, so attacked an led bulb for its circuit to convert it
I have put one of those cheapo meters across the mains ti see what would happen........it didn't end well. most cars actually charges at between 14v to 14.5 depending on load
BigClive, I need your help , I've started a project and I don't know what I am doing. I thought I had a fair idea about wiring a few parts together But the wiring wording and diagrams are not what I learned . When I say learned , I mean wiring simple 12V to a switch and then off to a light ,ETC. HELP.
Cheap meters will only frustrate beginners, just like cheap soldering irons are inherently more difficult to use. Get a regular meter second hand if you're a beginner
***** Ah, one of THOSE soldering irons, I remember it and the small roll of unleaded solder quite well. Absolute joy to the millionth degree. My current soldering iron is meh but it gets the job done decently. Gonna get a butane one to use for the thicker stuff. It also has a torch function if you remove the end. As for cheap meters, I use them when I don't feel like installing a measuring module with LED readouts. I just leave a couple sitting on top of said device for monitoring and I pull out my decent one for specific numbers. Like you said, I'd recommend something that's mid range, maybe $50 or so isn't too hard for a beginner.
Just for interest, newer cars (mine included) use silver calcium batteries, which are rated at 14.8V (not 13.8V). They're common in modern vehicles with stop-start engines. www.yuasa.co.uk/info/technical/silver-calcium-batteries/
What would you use to run a 12v fan on a UPS Back up it has a 24v van in it and it is going out needs replaced I have a 12v fan that will fit into it but don't know what to use to cut the power down from 24v to 12v. Thanks for any help you could give.
+Big Don Big Don You can buy cheap buck regulator modules on ebay that will reduce the 24V to 12 or indeed any voltage you like. (So the fan could be nudged down a bit for noise reasons.)
+Richard Deasington Running two in series is complicated slightly by the fact that each fan is drawing its current in pulses as it energises each winding in turn as it runs at its own speed. So the voltage across each fan will be spiking at higher than 12V when one fan is trying to draw current and the other is between driving two windings. It can be done, but some fans may behave oddly and make strange noises.
+Richard Deasington That could certainly help. In the past I've also used a 15V zener across the fan to limit the peak voltage without conducting at the normal voltage.
cement resistors at close to their rated wattage get smoking hot. I would go with a metal strap as a hold down. Actually I'd likely use a resistor more than double the wattage. Because whoever rates those things is clearly insane.
***** as always its a middle man who squeezes the price, and on ebay its to appear above the list of other sellers, my question was not anti chinese but one of an economics one
+Roland usually industrial stuff is built fairly well (but there are rubbish products in the industrial field as well, remember the unreliable ETR470?) but consumer products are often chinese products rebadged as "made Italy ®"
+jusb1066 well I don't know what the actual price is but you can get those regulators on aliexpress for as low as 70 cents and ten 5W resistors for about $1-2, so I would presume that the resistors are indeed cheaper but it only costs them about double or triple of one to just put a regulator in it and offer a slightly better product.
Doesn't strike me as being the kind of fellow who gives two hoots. I'm sure he's glad to have a following, but I think Clive makes these vids as an enjoyment more than anything. That said, I look forward to the video where LEDs are added to a silver play button...
+aszi88 I just threw it all in to one power rating deliberately. If I'd thought about it at the time I'd have monitored the LED voltage at each current level to give its actual power dissipation.
+bigclivedotcom I mean at the end when you measured the power at 12V you said it's 7.2 W which is still pretty acceptable and same as with the regulator. But the resistors dissipate 0.6^2*3 = 1W so the LED only provides 6.2W. (I don't know how much the regulator dissipates though.) Same for the 10V measurement. You don't have to measure the voltage on the LED as you know the resistor value and the current, so voltage on the LED is U-R*I, or the power provided by the LED is U*I-R*I^2.
Clive, as you were describing this little PCB and then the full bridge rectifier, I was almost sure you would identify the IC as a BP1601 a similar tasked chip whos input range is smaller typically 12v ac or dc, driving 4 to 7 - 1watt LEDs And you may have them for a small pile of beans on ebay. They have peculiar two pronged 1" long spears >> goo.gl/C7u5Be
Glad to hear your not a meter snob, Clive. Too many folks insist that they would not touch them with a barge pole, even for the most simple 12v tasks. Like you say, it's all about common sense, knowing it's limitations. Certainly good enough for a lot of hobbyist applications.
+100SteveB Agreed, I keep 2 or 3 in the box of 'fix the car stuff' that lives in the car boot. If I drive over it in a mud puddle, who cares.
*****
Yep, i have one living in the boot of my car also (Along with a ton of other stuff that seems to have found it's way in there).
+100SteveB I keep mine in my car's welly, just in case it's storming out. /badjoke. I keep meaning to pick up a few more since they are so disposable and we don't have any functional meters at work. I hate running into a simple problem where a little info on voltage could solve it, just to be left guessing.
+100SteveB I agree, glad to see Clive saying so. I probably have 10 or more of those Harbor Freight meters. I get one for free whenever they're doing that deal and I go in for anything. I like having a meter in the car, one in each tool bag, one in a desk drawer at work, etc. I've never needed much accuracy - if it'll tell me 30 milliamps or 1000 ohms within 2 or 3 percent, good enough for me. In reality, I've put it up against the best meter I have (Extech) and it's always within 1 least significant digit, tested across 3 or 4 < $5 meters.
If you want to see something explode, watch Big Clive's video with the "TIG welder" and that Chinese "AC/DC LED" he connected directly to line/mains voltage. (Was that posted on April 1st? :-)
Good to see you using "real world" equipment. Certain UA-cam personalities would have people believe that everyone associated with professional electronics has a Fluke meter, Hakko (never seen one used in anger the UK to be honest) soldering station, and multi-Gsample digital scope. The real world is much more like this: A cheap meter that is just sitting around the place and works absolutely perfectly on low voltages, and a Weller iron that you've had for 20 years and never lets you down.
90% of the time i have no idea what Clive is on about. Yet time after time i'm watching these tear downs with great interest. :-)
Did you watch his electronics basics video from a few weeks ago? It helps :)
I know what you mean though, the more advanced theory is way above my head, yet still I watch!
+lazaglider no I missed that one. I check it out. I know about house wiring but electronics are a completely different league :-D
Gotta love how the little circuit board is in such a shape that it could be inserted and potted inside the base of a lamp. They are very generic drivers but they work, but it seems the designer had originally made them for lamps such as bi-pin MR16 form factor lamps. If you go try and buy replacement drivers some of them even come with the pins soldered on the input side.
I recommend the small 10€ Uni-T meter, its super small, has fixed wires, a very clever position for the fuse (but only 200ma max because of that) and a little signal generator, which is about 75hz.
I use it more than the expensive Fluke, because its accurate enough for almost everything.
Its the Uni-T UT20, or the Voltcraft VC-11
The original use of these regulators (in that exact form factor) is in LED spots made for direct replacement of halogen spots running on 12V AC. That's why they have the bridge rectifier (and often come with the pins for the halogen socket). If you get them in bulk, they cost maybe 1€/$/£ a piece on ebay. I got quite a few of them and always removed the Schottky diodes (gets the useable voltage range down a volt). For current adjustment I just piggy back another SMD resistor on top of the one already there.
+superdau Good tip on removing the bridge rec! Makes sense.
This is actually very interesting, since I've been toying around with the idea of using some of these 12V lights to illuminate the trees in my back yard at night, and then have a small solar array and bank of those 12Ah SLA alarm batteries so they're ~green~ (and I don't have to fuss about with mains voltage which honestly still scares the pie out of me).
thats another reason i like you more than EEVblog, He constantly just says everythings crap if it doesnt cost $400, i dont have that to spend on a hobby where i just break things and make motors spin faster than they should.
Very interesting video. I have one of those meters - the only thing I have found with them is the rotary switch contacts got dirty after a while and I had to open it up and clean them. It did occur to me that, for a Chinese factory, a little regulator circuit might be cheaper than a ceramic wirewound resistor.
I usally get those drivers to change the resistors: at the end, just changing the current sense resistor you can make it to suit your needs (100mA/Rs), and then they work from 10V to 24V... Quite useful actually and more efficient than "big resistor"
I german, there is the therm "Drossel" which is pretty much identical to "choke". Both therms can be used for an inductor, and "choking someone" is "jemanden erdrosseln".
Also "coil" and "Spule" work very similary in german and english. In normal use, we call it "Spule". "Induktivität" is the more academic therm, which we tend to use when going into details, meaning non ideal models. "Drossel" is rearly used - I tend to use it, when I don^t care about specific characteristics.
Choke translates fine into Australia, primary used here in reference to a high frequency blocking inductor but sometimes used as a generic term for an inductor (generally larger than smd)
Just watching this now adn can't help but think the sooty skid mark is from a mains power supply driver smoking itself and the whole thing being recycled as a 12volt light :).
Those cheapy meters are great for general use. I love them for basic use.
Yay! :D He listened to me! I asked him to take apart one and he did it! Awesome!
+HDMcraft He takes loads apart that is this channel.
"Choke" is a commonly used term in amateur radio. Most often, it's used to refer to an inductor built by coiling coaxial cable (a multi turn air core inductor) or snapping a ferrite bead/core over it to block common mode radio frequency current from flowing over the outer shield and wreaking havoc.
73 de AF6AS (my callsign)
+Chaplain Dave Sparks - Sometimes Clive wreaks of havoc.
i have a $70 multimeter from my local auto store. it is cat IV rated at 300v i think. it has decent probes on it. nice big ones. i have had it for two years and i use it daily. Works very well. i have used it on 240v and all was well.
BC, re: glass, perhaps the obvious would be to cut a fresh piece from that pile at the bottom of the garden. Clear all the way to the edge. Cheers, Andy
+Andy Reynolds Ironically I just disposed of a load of old greenhouse glass.
Very nice
Typical idle voltage in a vehicle is around 14.2V, maybe a tad less with accessories running, but it will pick back up once the RPMs come up. This also gets worse in the cold where you can reach 14.8-15V. And with a worn battery you can see as low as the nominal 12V with the engine off and accessory power going.
Yep, the charging voltage for lead acid has a negative temperature coefficient, that is the needed voltage goes down when the temp goes up. In below freezing conditions the voltage can be just over 15.
+codemsan Car systems are notorious source of mysterious peaks and voltage fluxuations, so I'd say it's just good if that lamp can handle say 20V ...
On the same note.. I have seen Led worklights with 9-36V voltage range. Most likely having similar chip in them.
I like this guy for many reasons, but a main one is that he doesn't wave his junk around in everyone's face by having to have the most expensive Fluke multimeter on display in every video but uses a modest reasonably priced one.
In the US there is a paint remover called Citrus Strip. If it's available in the UK it might solve your problem with the faceplate. Good video.
I burnt one of the cheap meters testing a laptop power brick (Shorted straight to mains, good thing I always check them or that would be one dead laptop). I threw it straight to the trash, kept the leads whose wires I had gone to the trouble of replacing, and bought a similar one. I mod them to include a 9/12v barrel connector socket (with a filtering cap) and use that to load the 9v dry cell when it goes dry.
I have a goodish one (Supermarket loss leader), which I use sparingly.
The low rated voltage of the electrolytic would be no problem for using the floodlight at 24V. The cap is at the regulated side of the switch-mode regulator parallel to the LED, at least his position at the PCB suggests this.
Hi Clive, do you have a video on how to use a meter like you had in the video? If you don't, would you be able to make one? I don't know a lot about electronics, but I love watching your videos and find them very educational as I'm trying to learn more. You're fantastic at explaining things and are very clear about what you're doing when you are taking electronics apart, plus I love that your videos come across as very genuine as you're passionate about what you're doing. Cheers!
+MusicVideosExtreme I probably will do a dedicated meter video. I've actually just ordered a bunch of the cheapest meters on eBay to test too.
+Markus Bates Many of the little analogue meters are made in the same style. Just some diodes, resistors and a 100uA sensitivity movement. I can recall an old Tandy one that was made like that.
+Markus Bates Before digital meters analog meters were all that there were. You used to be able to buy a little 2x3 inch analog meter for about $5 at many hardware stores, or mail order. Electrical supply companies would give them away as party favors. They fit in your pocket, and believe it or not were designed to measure 600V AC. They were commonly used to measure 110V and 220V with no problems at all. YOu really don't need seven inches of triple insulated plastic to measure line voltage with reasonable safety. I used them for years as throw-away meters. A lot easier to use than a 7-pound Tripplet on the top of a radio tower to check the power on the warning lights.
+l wilton But you will need metal film resistors and other internal parts that are actually rated for >220VAC (600VAC ideally). In those cheap meters, mostly they aren't. I actually had an analogue pocket meter blowing up due to this.
There may be a single diode on top of the board that has the name SSXX (XX= 24,34,54 etc.) The voltage rating of that diode gives a good idea of what voltage it can handle. I bought one of those drivers a few years ago and it worked well with the max voltage i could give it ie, 18V). Functioned with DC as well as AC supply.
Pretty interesting, I never thought that one would use this for a car.
+Lucas Solomon Well, around here people put all kinds of superfluous lights all over their lifted trucks. I was considering making a cheap LED headlight out of a 10 watt chip, but the hole for it to fit through was smaller than the chip by itself.
One thing to consider is that the absorption charging voltage of a modern lead acid AGP car battery is 14.4v, and the chargers will have temperature compensation which will increase the voltage still further perhaps as high as 15.5 in extreme weather.
+James Lewis With the slight increase in LED voltage at the higher current that would probably just boost the output by a few watts amply catered for by the extra cooling of the weather. I'm not at my workshop at the moment so I may actually test that arrangement at worst possible voltage scenarios.
+bigclivedotcom Agreed... it's something I had to consider for a solar power system also, since the better microcontroller driven charge controllers will periodically deliberately overcharge the battery bank (depending on the type of battery) to balance it... so you can find that on a nice sunny day it decides to push the voltage up to 15 or a bit more... so stuff connected to that system needs to be able to cope with that.... of course you probably wouldn't be using a floodlight when that's happening.
First time I've ever seen anyone put that many resistors in parallel.
+Madness832 Probably the first time I've put that many resistors in parallel too.
"Choke" translates just fine to my half-American, half-Canadian brain! :)
+rhkips translate
Same in my norwegian, french, guatemalan brain :)
A choke is the same in english, I think he's confusing metric and imperial, most scientifit people use standard terminology.
I don't know the analogy of what a choke does... strangle?
One of the unbranded meters turned up free with an Ebay order for electronic parts, and has proved very useful, and is accurate. I have got an Avo or two, etc and old GPO test equipment bridges, and the accuracy is up to any test I can come up with. We used to make BS test equipment, (to test the standards), and I had previously tested another makers Chinese digital effort and it was dead accurate.
+stephen wallin I've just ordered a couple of the cheapest digital multimeters on eBay. So I may do a showdown with voltage tests compared to a Fluke.
Of course you can do it, come near 10W drive for it with a resistor, but the problem is that these generic LEDs don't hold up well at full current unless you have a very good heatsink.
Try running it at 10W (drive, not total) for a few hundred hours. When I did, albeit with a different heatsink, 6 of the 9 LEDs blew out in under a week of continuous run time and the remaining 3 were operating at a fraction of their anticipated wattage.
Have you ran any of these lights, with resistor or switching driver either way, for hundreds of hours? I suggest that keeping them at 5W or lower peak drive current is the best alternative to end up with something that has a more reasonable lifespan, or moving to a higher quality extruded heatsink mounted in the floodlight chassis, open at the back with a low RPM fan on it. A Pentium 2 era CPU heatsink would suffice. Naturally that won't be as robust for rough handling or rainy conditions.
Excellent channel Clive (if I may call you that) I wondered if you had any experience of the Kit: Executive power bank. Model PWRIP6SL Capacity 4100mAh. Its supposedly for iphones and iPads. I was 'forced'to buy one recently when I stupidly left home without chargers. £27 pounds worth in a station shop. I have to say it looks good and charged my phone no problem straight out the box. Charged it from my office PC USB and again no apparent problems. Recharged my phone three times without recharge. However after charging I had to try it in my ipad. It gave it some charge but become very, VERY hot. to warum to hold. That worried me. But after recharging it was apparently ok and works fine with the iphone.
Comments welcome
Hugh
For future reference, a lot of the newer cars tend to charge at around 14,5-15v. A minor detail but would make all the difference in terms of LED smoke production.
+keltickiwi Hmm, I've tested it up to 14.5V with the 3.3 ohm resistor (11 watt dissipation from the LED) But 15V seems really high for a battery charging voltage.
bigclivedotcom I believe many newer vehicles are fitted with silver calcium batteries which have a higher charging tolerance/requirement. However, I Can't say I've heard of the extra voltage causing any issues with accessories.
As far as automotive applications go, Clive, you forgot something; the vehicle's alternator/generator. With the engine running and the alternator being driven by the serpentine belt, you'll see around 14.5 volts, a maximum of 14.8 volts typically. I can't speak for bigger trucks (lorries) but I would presume the principle would be the same but a different voltage.
+Bryan Young For lorries it would be 27 volts for charging as they run a 24 volt system
I was thinking it would be somewhere around that mark. I don't have any experience with larger trucks, only 'civilian' vehicles that operate on 12-14 volts.
+Bryan Young it varies by car, expect between 13.2 and 14.8
+Bryan Young Can also be 28.8V (2x 14.4V)
I'm fairly sure that if you're getting spikes to that magnitude, something isn't doing it's job properly.
Thank you for your help I will try that.
Thanks you for the great videos.
it would be really interesting if you did a comparison of cheap leds (or cheap products) against their premium counter parts.
I was under the impression that standard 12V charge rate was 14.2V. Car thingers should be built to tolerate somewhere in the ballpark of 14.5V.
+Markworth Agreed, and that's just in a functional system.
+Marcus Cometti How do the headlights tolerate that? Doesn't that shorten their lifespan?
Awesome review and mod my good friend.
Someday I'll study the history of electricity, specifically how different voltages and frequencies became standard in different countries. I'm sort of partial to the 120/240 60Hz system we have in the USA. The higher frequency does help make transformer design a little easier, and center tapping the transformer to provide two different voltages provides a safer voltage for small loads plus the lower current 240 volts for larger loads like air conditioners, stoves, water heaters, etc.
Load balancing can be an issue. Each side of the centre-tap on the transformer should be under the same load, but that is seldom the case in real-world use. If the centre tap is lost then you can get closer to 230 V on the low load side - fire risk. There is no safety advantage to the 115 V system.
In theory you could cut down on insulation, to save some money, but you'd pay a lot more in copper for the larger conductors required. So the lower voltage used is mostly a disadvantage, then you have the complexity of different appliances requiring different outlet types rated at the full or half voltage.
A higher frequency is better, but 60 Hz isn't that much different to 50 Hz so you don't really get a huge benefit from decreased transformer sizes. Aircraft use 400 Hz to get the transformer weight down. With the ubiquitous multi-voltage / multi-frequency power supplies
Shock and Awe: The Story of Electricity -- Jim Al-Khalili. Definitely worth a watch.
+boggisthecat Yes, not many understand load balancing. The house I grew up in suffered periodic low voltage which caused the picture on our vacuum tube TV to shrink. The TV repairman reported this problem. We called the power company and they reported that ALL of the breakers were on the same leg! The house was also built in 1959 when a main breaker wasn't required. This shortcoming nearly caused the house to burn down when one of the bus bars was accidentally shorted while doing some electrical mods. (No, it wasn't me doing the work!)
As for insulation, no savings there. It all has to be rated for 600 volts, regardless. Speaking of saving copper ... there was that brief period in time when ALUMIN[I]UM wire was allowed... So many fires ... and lawsuits!
I actually connect cheap chinese meter into mains (~230V) set to 200 or 20 mA and nothing spectacular happened, it's blown (with a bang) the fuse for the amps measure and some resistors inside, but the rest of the functions were just fine, i'm still using it from time to time
Hey Clive, is there a way to send you a few things to take a look into them and why they failed? ;) Just asking before I'd throw them away :)
+EpicLPer He has done it a few times in the past.
+simontay1984 - LOLOLOLOL... his website is right in his channel name! LOL... no Googling required! Read it again! ;-P
You might be able to scratch that black stuff off using a steel brush. The glass won't scratch, because glass is harder than steel.
It's hard for me to admit it, but those cheapie meters are probably okay for beginners on a budget, and as Clive said, not needing high accuracy, or high-voltage or -current measurements. Though if it were me, and I had to throw a voltmeter at my "younger self," I'd probably give him an old analog Simpson VOM, or maybe a Heathkit VTVM. ;)
That black stuff might be one of those "paint & bake" type coatings, where it's literally melted/fused into the glass. Just guessing, though.
Not sure if it would work for enamel on glass, it would also depend on whether the glass was etched, but a stanley blade held so the angle of the sharpened edge is flat on the glass may work, i use this method for cleaning crud from glass.
You may want to put the glass on some thin rubber to stop is slipping around
+Sparky Projects The sharp knife just slid across the paint like glass.
+bigclivedotcom Sounds like it's grinder time, if it scratches the glass, just do the same all over the glass as a diffuser :D
another interesting vid! just waiting for the drivers and im converting my 100w halogen floods to 20w led chips
Nitric or Triflic acid should be able to remove the paint from the glass, but remove it before it etches the glass.
Did you try a drop of brake fluid on that paint?
I was thinking a couple of 1 amp diodes would drop about 2v at full current and less as the supply drops, a possible, maybe :-)
+zx8401ztv I've not actually tried brake fluid. I'll give it a go.
What about just cutting a new bit of glass for the solar panel?
Just borrow a pane from the neighbours greenhouse. 👍🏼😂
+Green Silver Darn! (I just threw away a load of old greenhouse glass.)
+bigclivedotcom it sucks when that happens!
+Green Silver Yea, people call me a horder because I hold onto so much because "I'll need it" or I could use it. Funny thing is if I'm prepped for a situation it never happens.
hi clive!! for a cheap dmm I like uni-t. cheers
+Proyectos LED It's a shame there's far too many fakes for the uni-t meters. I have a ut139C that works very good and has decent protection.
Unless it's guaranteed to be one of the big name brands, I have to open them up and see how well they're built and protected to be comfortable using them.
loved my uni-t meter. Used it roadside for years. left it sat in someone's engine bay, so it is now probably somewhere on the side of the M5
Try using sulfuric acid to "burn" the paint off. I've used it on some beer glasses to remove part of the branding.
I have a bunch of those I am going to turn into an array of solar garden lights :D
Could the coating on the glass maybe be two pieces of glass pressed together with a plastic insert? That would work and make it heat, UV and waterproof.
+Alexander Presslie
No, this is definitely not laminated glass. The paint (or whatever it is), is clearly on the outside of the single piece of glass.
Maybe you can make a home-made current source to sink 900mA. First step would be a Voltage reference (7805 or resistor+zener) with a potiometer to drive a npn transistor sinking the current and with a resistor (1ohm) connected to the base. Of course it's far from perfect but should be better than just a resistor. When proper current is obtained, replace the potentiometer with resistors for better long term reliability and lower cost.
+c muller Two transistors and two resistors would let you regulate to any current you liked, but would dissipate excess power as heat.
Sure, but this is what a simple resistor does anyway... The advantage of the transistor current source is a much better stability of the current when the voltage raises (vs simple resistor). The power will actually be dissipated in the npn and base resistor so they share it. The base resistor does most of the job if v is 12V and the npn dissipate more as the v raises. The extra cost is not high and you won't need a high power resistor (less that 1W in the 1ohm that can be done with 5 x 4.7ohm 1/4W in theory). To220 npn are not expensive and can be screwed to the box.
I rewired a 240 v Les spot into 12v but it was a messy affair with cutting the board and welding leds in parallel. Could you show us a more straightforward way?
When you said the dissipation at 12V was around 7W, that included the resistors, dissipation in the LED is about 6W or so, at 10V the LED dissipation was right about 2W. Close enough though ;)
think we need a meter test next. current setting across the mains plug :)
Already have it won't end well, still got no feeling in the last two fingers on my right hand and it was 3 yrs ago 🤣🤣🤣
3:44 lol I can reference to that. I stuck my meter across the live and the ground pin of the mains without realizing the leads were in the amperage position. Blew a good chunk out of my meter leads.
Hydrofluoric Acid should get that black stuff off, oh, and dissolve the glass as well......probably, if you could get hold of some! ;D
congrats with the 100000 subcribers clive!
Ritchie
3 years on and he’s now over 544k!
Couldn’t happen to a better person with an awesome channel.
the power dissipated in the resistors will be I^2 *R. in the 12v case .6*.6*3 = .36*3=.99+.03*3\approx 1W.
cheers looking forward to any advice you can give a beginner needing a test meter thats not going to break the bank..thanks
+charlieoscar09 Just buy what you can afford. Most cheap meters are still accurate enough to be perfectly usable for electronic stuff.
Clive, I know you've done teardowns of USB battery packs in the past, but PoundWorld have just started stocking one in the UK. Would you be interested in checking it out?
+Daniel Dowling I got two. One of which had a completely flat cell in it. I'll probably cover them in a video.
Thanks for the reply but two fans will not fit in the USP.
Have you tried soaking the glass in methylated spirit? With it tasting so bad, it must be able to move the mask! LOL!
Shouldn't be too much of a hassle to cut your own glass panel if you were really keen on making the whole thing clear. It just wouldn't be tempered glass, but I'm thinking the current glass isn't either.
Typical charging voltage for car battery is 14,4v (but it can by between 13,2V to 14,8v).
+omyk22 I did think that. Numpty boy here diagnosed a dead alternator by checking that.
The squealing, smell of burning, and the too-hot-to-touch alternator housing were also a bit of a clue, too ;)
The term "choke" is used in the US as well. Couldn't say for the rest of the world though.
hi mate love your videos.is there any chance you can do a video explaining sequence of testing r1 r2 etc there's a lot of videos on UA-cam showing how to do the tests but none explain why these tests are done and what if you get bad results or readings.cheers
The primary purpose of the R1 R2 reading is to determine if the resistance of the supply (live) to ground (earth) is low enough to pass enough current to trip a circuit breaker instantly by actuating its magnetic trip mechanism. This will depend on the current rating and type (A, B, C or D) of breaker due to the C and D breakers being designed to handle much higher inrush currents to things like transformers. If your circuit reading is too high it could be that the cable run is too long or there could be high resistance connections along the circuit. I should make some electrical test videos at some point. It's worth mentioning that if there is an RCD covering the affected circuit then the original purpose of the R1 R2 test is rendered moot since the RCD will trip first in the event of a live to earth fault.
thanks for the reply.im new to testing and want to know exactly why I'm doing a particular test and why iv got a certain reading rather than just writing a figure down after testing.theres a guy called John ward who explains things well on UA-cam.not on a par with you though.cheers mate
pls put it on 240v, I wanna see it blow up
you will go blind.haha
+Joshua Nicoll I've tried blowing up the power LEDs on 240. But they fail in a very controlled and boring manner like an HRC fuse.
I meant the little power supply, LEDs tiny gold bond wires are designed to be fusable to an extent
+bigclivedotcom I wouldn't mind seeing unfused 240V straight across the 10A input of that "cheapie" meter.
+Brandon Fesser Strangely, I was thinking about that... And pondering whether to test the 10A or the lower ranges first.
yo Dr Clive I just got a 8 pack of these exact lights from eBay to run in conjuction with my ista breeze i500 wind turbine and 6x lead acid batteries would u recommend running each of these of a 1a fuse and would u do a review of the i500. cheers Charlie fae Falkirk.
+Moonkiny dmf Lots of fusing is always a good idea.
@bigclivedotcom Can I ask how did you get the 900mA initial estimate? I've got a similar LED lamp with the same regulator circuit and chip (I blew my rectifier diodes up by stupidly plugging it into the mains. Super sparky and magic smoke! =__=), but has a white colour.
I've tested it on my power supply, and am getting 15V 0.66A (to get to the ~10W output). Any pointers on how I can get the proper operational voltage and current?
The packaging on my lamp didn't have this information (and because I haven't touched this light in over 2 years, the eBay page is gone :( ).
lol that is a huge bundle of resistors
Typical alternator output on a car is supposed to be 13.8-14.2. Not uncommon to see them around 14.5. I have seen regulators go south and cook the battery at 19 volts. One advice i have for people that have a dead battery. Check your charging voltage, you can fry a brand new battery quickly (learned from experience).
I use a similar cheapy meter as a 2nd/backup meter and I was happy with it for what it is until I blew the fuse and when I opened it to replace I found that there wasnt even a fuse holder, the fuse was actually soldered to the pcb. built down to a price is fine, I paid less than 5 quid for it, but seriously thats cost cutting taken too far
Have you ever compared the volts and ohms accuracy of the cheapie meter to something really expensive like your old fluke?
+Derp Herp I've just ordered a bunch of cheapo's for a suitable showdown. (With the Fluke.)
bigclivedotcom Looking forward to that video!
we call them chokes here in the US too, I think it applies to most English speaking countries.
Why not replace the painted window for plain glass?
I was wondering if a 12v version of these lights would turn up... :D
+twocvbloke been out for a long time, my portable led worklamp is one of these (put together by me) and a 12v 7ah lead acid, came out before the ones with a lithium pack on them, so about 4 years ago. both portable and charged via cigar lighter as was the need
jusb1066
I was referring to the entire package, not the LED module... :)
*****
yes the entire package is what i refer to also!, in fact back then i also wanted a 240v ac one, did not find one, so attacked an led bulb for its circuit to convert it
You should do a video with photonicinduction!!
I have put one of those cheapo meters across the mains ti see what would happen........it didn't end well. most cars actually charges at between 14v to 14.5 depending on load
BigClive, I need your help , I've started a project and I don't know what I am doing. I thought I had a fair idea about wiring a few parts together But the wiring wording and diagrams are not what I learned . When I say learned , I mean wiring simple 12V to a switch and then off to a light ,ETC. HELP.
Cheap meters will only frustrate beginners, just like cheap soldering irons are inherently more difficult to use. Get a regular meter second hand if you're a beginner
*****
Ah, one of THOSE soldering irons, I remember it and the small roll of unleaded solder quite well.
Absolute joy to the millionth degree. My current soldering iron is meh but it gets the job done decently.
Gonna get a butane one to use for the thicker stuff. It also has a torch function if you remove the end.
As for cheap meters, I use them when I don't feel like installing a measuring module with LED readouts. I just leave a couple sitting on top of said device for monitoring and I pull out my decent one for specific numbers. Like you said, I'd recommend something that's mid range, maybe $50 or so isn't too hard for a beginner.
Lots of Japanese cars, and some german cars charge at 14.4V nominally
they are for sale at harbor freight tools for 99 cents US this month limit 9
Just for interest, newer cars (mine included) use silver calcium batteries, which are rated at 14.8V (not 13.8V). They're common in modern vehicles with stop-start engines. www.yuasa.co.uk/info/technical/silver-calcium-batteries/
Choke is the same in the U.S translates to coil o wire
If you can't get that stuff off the glass maybe you could cut a new piece?
What would you use to run a 12v fan on a UPS Back up it has a 24v van in it and it is going out needs replaced I have a 12v fan that will fit into it but don't know what to use to cut the power down from 24v to 12v.
Thanks for any help you could give.
+Big Don Big Don You can buy cheap buck regulator modules on ebay that will reduce the 24V to 12 or indeed any voltage you like. (So the fan could be nudged down a bit for noise reasons.)
Get two fans and run them in series.
+Richard Deasington Running two in series is complicated slightly by the fact that each fan is drawing its current in pulses as it energises each winding in turn as it runs at its own speed. So the voltage across each fan will be spiking at higher than 12V when one fan is trying to draw current and the other is between driving two windings. It can be done, but some fans may behave oddly and make strange noises.
+bigclivedotcom Interesting point - didn't think of that. Perhaps a decent capacitor across each motor would smooth it out enough - say 470 mic?
+Richard Deasington That could certainly help. In the past I've also used a 15V zener across the fan to limit the peak voltage without conducting at the normal voltage.
cement resistors at close to their rated wattage get smoking hot. I would go with a metal strap as a hold down. Actually I'd likely use a resistor more than double the wattage. Because whoever rates those things is clearly insane.
"it has a full bridge rectifier" - have you been watching electroboom?
For whoever is interested: CL6807 datasheet akizukidenshi.com/download/ds/chiplink/CL6807_p.pdf
is the active circuitry cheaper for china to supply than a 5w ceramic resistor?
*****
as always its a middle man who squeezes the price, and on ebay its to appear above the list of other sellers, my question was not anti chinese but one of an economics one
+Roland usually industrial stuff is built fairly well (but there are rubbish products in the industrial field as well, remember the unreliable ETR470?) but consumer products are often chinese products rebadged as "made Italy ®"
+jusb1066 well I don't know what the actual price is but you can get those regulators on aliexpress for as low as 70 cents and ten 5W resistors for about $1-2, so I would presume that the resistors are indeed cheaper but it only costs them about double or triple of one to just put a regulator in it and offer a slightly better product.
Choke is a term that works in the US
A bit of sand paper might take off that black coating.
That piece of glass, you could replace with regular picture glass, the only cuts required would be straight (4 edges, knock off 4 corners)
+TheChipmunk2008 Thought about the picture glass, but the existing stuff is quite thick.
+bigclivedotcom Maybe acrylic of some kind? Places who do license plates for cars have it available :D
Try soaking the glass in brake fluid for a day or three.
+madmat2001 I think brake fluid might work too but just cutting a new piece is very easy.
I have one of those yellow meters by blue spot
Dose he even realize he now has more than 100,000 subscribers.
Doesn't strike me as being the kind of fellow who gives two hoots. I'm sure he's glad to have a following, but I think Clive makes these vids as an enjoyment more than anything.
That said, I look forward to the video where LEDs are added to a silver play button...
You forgot to subtract the power dissipated by the resistors.
+aszi88 I just threw it all in to one power rating deliberately. If I'd thought about it at the time I'd have monitored the LED voltage at each current level to give its actual power dissipation.
+bigclivedotcom I mean at the end when you measured the power at 12V you said it's 7.2 W which is still pretty acceptable and same as with the regulator. But the resistors dissipate 0.6^2*3 = 1W so the LED only provides 6.2W. (I don't know how much the regulator dissipates though.) Same for the 10V measurement. You don't have to measure the voltage on the LED as you know the resistor value and the current, so voltage on the LED is U-R*I, or the power provided by the LED is U*I-R*I^2.
Clive, as you were describing this little PCB and then the full bridge rectifier, I was almost sure you would identify the IC as a BP1601 a similar tasked chip whos input range is smaller typically 12v ac or dc, driving 4 to 7 - 1watt LEDs And you may have them for a small pile of beans on ebay. They have peculiar two pronged 1" long spears >> goo.gl/C7u5Be