Just as "i" is the symbol for current and [A] is its unit, 'u' is the symbol for EMF (sic. voltage) and [V] is its unit. It is one of those quantities where people tend to use "u" and "v" interchangeably, but the correct and unambiguous notation would be to use "u" like the manufacturer has used here. To be sure, for DC EMF, the symbol would be a capitalized "U" (again, they've used this correctly). Finally, someone who got it right :) . If you feel like arguing: "But why be so pedantic, and use 'EMF' instead of 'voltage'?" ask yourself this - How much 'amperage' do you charge your LiPo with? gah! "Current" sounds so much nicer...
It depends. It's the SI-system. As I know USA still use gallons, miles, inches and probably V and E too. At least for some time ago. It's a cool table for SI-parameters for electromagnetism a little donw this wikipage. en.wikipedia.org/wiki/Electromagnetism
I have no clue if the U.K. test-certification is consistent in its nomenclature. The SI is. They use V as the symbol for electric potential (and not U). As I said earlier, people tend to use it interchangeably. In mainland Europe, for example, the word for this electrical quantity roughly translates to "tension" - not the kind of tension you'd get in a spring, but rather there is a separate word, also used for e.g. social tension, perhaps used similarly to the English "high-tension-cable" (I know that the cable-analogy is bad, since a high tension cable actually refers to its elastic tension.). That being said, any EE would understand what you meant if you consistently used either V or U as a symbol for electric potential. The down-side to using "V" is that the symbol for the unit is exactly the same "V". This makes an (in?)equality like "V = 12V" give me the creeps. In any case, I'd recommend NOT using the symbol E. This is used categorically and universally to denote the electric-field, with a unit volt-per-meter (V/m) [which is the same as newton per coulomb N/C].
Aditya Mehendale rather than I = 5amps where as v can often stay as a constant measurement and unit I understand not fully grasping the cable elasticity thing but I'm not electronic so much as electrical if that that makes sense I guess in the long haul it doesn't really matter as long as you know not to earth it or short it your ok
U is symbol for voltage and it is measured in Volts -> U = 5V I is symbol for current and it is measured in Amps -> I = 2A Ohms Law is normally written as U = R * I OVP, OCP, OPP are abbreviation so they use V/C/P instead for symbol used in physics expressions. Be carefully with those protections. Depending on device it may be only hard limit, it may shutdown or clamp input. The last option with no protection on input may ruin your day (although it seems that this meter simply power down). Thanks for review, I was thinking that I get this device and now I know that I want it :)
The answer to your question regarding the Letter U - That's us scot's fault, now adopted across Europe. Traditionally quantity (here voltage) and its unit (volts) are kept separate, which means using different characters for either: current (I) is measured in amperes (A) and resistance (R) is measured in ohms (the upper-case omega). Having V to mean both quantity and unit sort of violates the spirit. So we use U to denote quantity.
V in our Europe is for Velocity. Letter U is for Unterschied which means "difference" in German like potential difference. And also at that time they ran out of letters for physical properties.
I must admit. U i have not heard of. At uni, our calcs were, I =E/R current, Electromotive force, Resistance. I would say the U is a typo in the translation. U is not a standard abreviation on the IEEE standards
Seems like U as a symbol for Voltage came from the latin word urgere. Also atleast in germany we have our own standard organisation for electronics stuff (VDE) which is often used which specifies U.
In the UK we still use V for voltage at school and for more advance courses an epsilon (Ɛ). I think at university we used an uppercase epsilon for DC voltage and lowercase for AC voltage, but that was over 10 years ago for me.
just to sort this out with an update. V is the symbol for voltage. ie, 2.5V. when making a calculation U is used because it is the outcome of a voltage/current or whatever calculation. my research has uncovered that the use of "U" is not a direct unit of voltage. The IEEE have confirmed this. I must admit, i didnt know this myself until it came up in the Video. V =voltage. U is used to indicate the result of a calculation in which voltage is one of the constants.
The overvolt protection 'normally' works by clamping the DC input short circuit if overvolt is detected. This might damage the DC supply, but save the DUT. Put a fuse inline with your battery pack please! Note: I suspect that your regulator/PSU may just open circuit the output, guess it is up to you to test.
I have 2 of these now. I love them I power them each from a lenovo laptop power supply (20 volt 4.5 Amp) and can use for 2 independent supplies or a +/- rail configuration. Have had no issues so far and the current and voltage displayed is spot on from my external metering.
That is the best option as they are isolated and will let you operate in serial ( 2x voltage) or back to back for a +/- supply. I haver a boatload of lenovo laptop bricks from work.
Hi friends. there is good news. we just publish the DPS power supply module ( DPS3003, DPS3005, DPS 5005 and DPS 3012) this is the link www.aliexpress.com/store/group/DPS-Programmble-control-power-supply/923042_508466030.html DPS series is updated version, it updates some function and measurement range is increasing, especially DPS 30V12 ( current is 12A)hz.aliexpress.com/store/923042 you can check ..
DPS series are updated version. Panel is different. In DPS series, we change the M1/↑and M2/↓ into V/↑and A/↓. You can press those button set the voltage and current fast. We add a new function “set default boot open or close output” Others are not changed.. DPS5005 still need diode to charge the battery.
U is the letter used in physics for energy potential which is relative to some other potential, this difference is measured in Volts which is derived from the potential energy needed to move charge based on Newtons as a measure of power and so on. In English U is voltage and measured in V which is volts which makes the definitions muddy. In other languages these are sometimes separated by calling U for example potential or something else which is measured in volts (V). You can't increase volt (V) no more than you can increase a meter but you can increase voltage (U) just as you can increase distance which is then measured in V, it's a fairly subtle difference but an important one.
In Germany voltage always gets named U. Uin - Uout - Udiff etc. U=R*I Why it's that way is pretty much unknown and very much limited to Germany. Some say it comes from latin "urgere" (drive, push)
The S-OVP, S-OCP, S-OPP are for the power source i suppose. If you have a power supply that is 50V, 2A to power this regulator you can set these values so it won't overload if it is unprotected. Pretty nice feature to have for diy projects i must say.
That was a great video , I’ just purchased the same. Looking device from eBay for $75 it has a higher output of 20 amps I intend to use it for some projects that run multiple large stepper motors
V is the (ISO) unit (Volt) of tension, U is the letter for the physical dimension (same as A stands for the unit of Ampere and I for the dimension of current). Not sure if in the US you use V also for the dimension, but as it is an ISO unit, you shouldn't.
Interesting little module, now just to get a 3D printed case with an external cooling fan on back with banana plugs on the front bottom under the display for power output out of the front. Pretty cool it has the CC/CV and protections cutouts built in. Not bad for $30, too bad it's not a boost/buck converter where you can feed it in 12vdc from an old busted 300~+ watt ATX power supply, have it be able to step up to 50~vdc or all the way down to it's minimum, right now it just looks like it is a buck converter and you must supply more input voltage than output voltage. Either way...pretty interesting little module, thanks for the review
I have this module and the 50v 20A version, I use it to charge 18650's, no need to use the diode just always connect and disconnect with the output turned on with the current limit set low, the diode will have a voltage drop so the output voltage will be less than on the display.
Well done! Your explanation showing CV vs CC modes was nice. A test with an LED strip would also show how CC mode can be used to control the LED brightness. Thanks for the video!! PS: I have always used V to describe voltage and E to describe electromotive force.
bought one even before this video ended. hopefully it will hold up - but seems like a great value & i'll find it very useful in some of my projects not only w/ Arduino, but with high-power LED's. thanks for this - you are an experimenter after my own heart! found you after watching iNav vids. Russ from Coral Springs, FL, USA
Hi friends. there is good news. we just publish the DPS power supply module ( DPS3003, DPS3005, DPS 5005 and DPS 3012) this is the link www.aliexpress.com/store/group/DPS-Programmble-control-power-supply/923042_508466030.html DPS series is updated version, it updates some function and measurement range is increasing, especially DPS 30V12 ( current is 12A)hz.aliexpress.com/store/923042 you can check ..
i have been using this 505v for some time now and really like it. i just gave mine away to my granddaughter who is very interested in learning all things Arduino (and eventually flying quads)... i'm not even all the way home (from Portand Maine to Coral Springs Florida) and i'm missing my supply/meter so much that i'm now ordering the DPS5015. nice unit! Russ from Coral Springs, Fl usa
About the U as volts, here in Norway we use U as volts, R for resistance and i for ampere. don't remember why we use U as volts since we only use URI in ohm's law at school where you use VRI? and I have never seen U instead of volt in real life outside school (working as a mechanic last 7 years)
Small, neat & I guess accurate; but unless you use regularly the setting routines would prove a challenge. I notice that any tripping of a protection setting might easily go un-noticed; maybe a flashing indicator would help?
The problem with this unit is simply that it is really involved to set the parameters for a data set, then saving. The instructions are very poorly laid out so initially at least it's quite demanding. The instructions (for example) refer to a potentiometer not the rotary encoder which it is. Ideally this should couple via SW to a PC & enable much faster & more reliable programming.
In school I was told the formula to calculate the power usage P=UxI (Power=voltage X amperage). This is ohm's law I always hated that formula and always wrote it down as W=VxA and got in a couple of arguments with my teacher. more than 10 years later, I saw that teacher in a supermarket, and he still remembered me. He told me I was one of the few students that actually cared about what he was teaching. And that he mist the arguments in class after I drop his course and went on with metalworking the next year. I stilt think of that teacher every time I use ohm's law
U, I and P is the SI-system's symbols for voltage (V), current (A) and power (W). So it's probably intentional. However, thanks for this video. One is on the way ;) If the maximum current can be preset, this unit will be perfect for powering high power laser diodes (which are current hungry, but easily destroyed at just a little overcurrent).
Interesting! Came across it as well.. Thanks for sharing this! :) Damn.. glad to see that loose wire didn't short something out :| Handy pandy thing by the looks of it :D
What I want to see is someone putting a 100W load on it and hooking it up to a scope to see just how much the output oscillates. The last Chinese bench supply I tested was going almost 1V peak to peak under load.
I bought one of these not long ago and use it all the time. I only wish when you push the button to change voltage or current that it would stay in the change mode until I push the button again to end or even better, have an option in the settings to have it work that way or the default way which is automatically exit the change mode after 10 or 15 seconds or no input. When I am experimenting and want to play with voltage and/or current it is annoying to have it exit change mode by itself so I have to push the volt or current button again then push the knob two or three times to get to the digit I want to change... wash, rinse, repeat.... Also, interesting that the manual calls it the coding potentiometer since, as you mentioned, it is not a potentiometer but then no surprise from a translated document.
I bought another one more recently that has the feature you mention, where the voltage changing mode stays until you turn it off. It's a larger power one though, so not sure if they have made this modification to the lower spec ones as well: ua-cam.com/video/siZTPRpyVrM/v-deo.html
Pretty neat device. It would be cool if it would have some data logging, or at least serial output with current voltage and current being drawn. The screen refresh is pretty low, at about 1-2Hz. I assume the protection mechanisms are implemented in software, and not using dac and comparators that triggers something. (other than current limiting I assume), which might be a bit unsafe. It most likely will deliver more current or power for about half a second, than what is set in settings, so still be careful. Any ideas about turnup / turndown behavior, noise, ripple and load regulation.
Well, it's been a year since the release of the video. Is this neat gadget still performing OK? Would you recommend it for a hobby-class variable power supply?
Late but hell just found this vid. U is potential energy, V(volt) is unit of measure of electrical potential. In electrical just kinda became voltage or just volts, as well but not as much I=current some times is referred to amperage or just amps.
2:00 the input voltage is 6-55V but there is no indication of an input current. Does it even matter because it will draw as much current as needed? And also, what should the min. input current be? btw. great video. EDIT: I researched a bit and as I thought, it depends on how much current you use and there's is a way to calculate it if you know the efficiency.
Thanks for sharing. I've been eyeing these lately. I have some higher voltage power adapters floating around, plus some 40 volt lithium batteries for lawn equipment. Would probably work out quite well.
if you want charge battery? it can charge the battery , but it need a diode. and when you buy this , the diode will be in the package. 40v lithium batteries is ok. input voltage is max 55v.. don;t worry , you can try hz.aliexpress.com/store/product/RD-DP50V5A-Constant-Voltage-current-Step-down-Programmable-Power-Supply-module-buck-Voltage-converter-color-LCD/923042_32596330856.html
I am wanting to build a case for this unit and was curious if I could wire the diode into the circuit all of the time or should it only be used when charging batteries? Any problem with leaving it installed all of the time?
Texas Ace If you put it in a case, you can easily wire a switch in the output that would change between diode and non diode output. It wouldn't take much effort to make that work.
Thats a good ideal, had no thought of a switch. I ended up just putting 2 sets of power jacks on it, 1 directly connected and the other run through the diode. Figured that having 2 outputs would not be the worst thing around anyways. Although for some reason I forgot that it is only a buck supply, so now I am on the hunt for a higher voltage power supply instead of an ATX PS. Think the best I have found is a 48v / A supply for $25ish, or since I doubt I will need that much power I might just go with the 3A version for $15. Still should come out to around $50 all said and done for a 50v/5A adjustable power supply, not bad at all.
J IJzer I received my electrical engineering degree in the 80’s and we were taught E=I x R. .E = voltage or electromotive force. They eventually changed to V. New engineers i meet in the field use V., but i still use E. I have personally never heard U used. I have worked with Engineers all over the world, but never heard them use U for Voltage. New to me. I’m not denying it, i have just never heard of it.
I think you are confusing voltage (across a component) which is often noted as "U" and electric potential of a node, which is often noted "V". U across the component between nodes A and B is equal to V at point B minus V at point A...
250 Watts! I have a 2 channel 150W Mastec that's 10 times the size of that thing that I paid $200 for. Wondering if I should replace it with 2 of these?
+iforce2d It's a european thing, that I know. But I don't think the origin is quite clear, maybe it's only done to not have two v's in V=12v, or because U was unused. Also, Unterscheid is difference in german... who knows?
U is the general abreviation for voltage :) U= Voltage I = Current R = Resistance U=R*I etc.
8 років тому
U is the potential difference and it is the correct symbol or letter to stand for electrical potential difference. The unit of U is Volt(s). The word " voltage" is an informal and wrong expression.
Very nice, I plan to combine something like this with an old ATX PSU to have strong cv rails and a variable output with these features. But I still have questions: what is the minimum output voltage and current?
Nice video test. For about $15 more aliexpress sells a Gophert power supply with its own power supply and a case. No including shipping. I would probably want that if I were to splurge on a this type of thing. It does not have that confusing u designation for voltage.
Gophert power supply , I know this , display is led display.. and it sells very expensive and it is very heavy. in fact it isn't worth the price .. you can this module .. 50v/5a , high precision and small volume.. it is very worth.. hz.aliexpress.com/store/product/RD-DP50V5A-Constant-Voltage-current-Step-down-Programmable-Power-Supply-module-buck-Voltage-converter-color-LCD/923042_32596330856.html
If you use this power supply to charge a battery, the manufacturer states you must add a diode in series to avoid back current destroying this module. I wonder if adequate protection would be there if you simply add a diode between the input and output +ve terminals, i.e cathode to the input and anode to the output? I remember when I built variable voltage/current power supplies around 30 years ago, this method got around the problem, otherwise damage always resulted when the battery voltage was higher than the power supply voltage. Otherwise if you just place a diode in the positive output leg, you're going to need to allow for a 0.6V drop across the diode and accuracy suffers. As the designer Glen Liu has been active here, I'd be interested in your comments.
Yes, I did see that in the video. I don't think you understand what I'm actually asking. When charging batteries, each type has a recommended voltage they should be charged to, for example a 12V SLA = 13.8V. By placing a diode on the output you need to compensate for the 0.6V drop across the diode junction. While not difficult, it's one more thing you'd need to consider when possibly this isn't necessary if a reverse bypass diode is fitted? That's why I'm hoping the designer can clarify this as he's been here recently.
Correct, I don't see what you're asking. To be honest I didn't see any difference between the two scenarios in your first comment, ie. "a diode between the input and output +ve terminals" and "a diode in the positive output leg". Both of these sound the same and are what that given diagram looks like to me. I better let Glen answer...
There's a big difference between those 2x scenarios. I'd show you on a circuit diagram if it was easy to do so. When I state the input and output +ve terminals, I'm relating this to the input and output positive terminals of the module. A diode fitted between the positive output terminal and the load (battery) is the method recommended by the supplier, but this is not ideal when setting the exact voltage seen by the load as a silicon junction (diode) has a 0.6V drop that is not exactly linear at low currents.
I see, I think. But that makes even less sense to me. So for example in my video here where I'm powering the module from a 3S lipo, the cathode of the diode would be connected to the positive terminal of my lipo, and the anode would be connected to the (in this case) 5V output of the module? Under what circumstances would current ever flow through that diode? And how does this protect the module from current flowing back from the battery? There are plenty of quick sketch sharing sites around - let me know if I'm getting this wrong: sketch.io/render/sk-9bc212b02d9709cd0a4df5ce2beaa593.jpeg
I just bought 1 of these but the 5015 witch is 50 volt 15 amp it comes with a driver and was $49 I am going to use an atx power supply to run it so should be good
So alternating current would burn it out so you have to have a battery. So I can't use it on a small generator. I never liked batteries because they will run out of power in the end. But I have to get my scooter running. I'm sure these medicaid people will want me to check in with my new doctor once they get the new of where I live. Last time it took them almost 8 month to get me a new doctor. I moved on the day I got their paper work. Just could not be helped. Thank You Loader.
Good review video. But for 30$ one can buy a complete ATX power supply capable of say 350W + ... Can be adapted/hacked to become a very good lab power supply with regulated outputs.
Oh for sure ... I mean it is a elegant and ready to go solution, no doubt. I only wish the price could be lower ... when compared with say a massively made ATX PSU ... looks expensive, otherwise it's no doubt very nice and very practical . I was by no means criticizing your choice. I am thinking to get one of those also, just sayin' hey seem expensive tho ...
I am the designer of this goods. we have my own shop on aliexpress hz.aliexpress.com/store/product/RD-DP50V5A-Constant-Voltage-current-Step-down-Programmable-Power-Supply-module-buck-Voltage-converter-color-LCD/923042_32596330856.html there are many other version. you can check
Hi friend how you get 0.9. are you sure you get 0.900? our module max error 10mA, please use a better mulitmeter to compare . and our module can't be calibarted. because we don't need.. thank you and Hi friends. there is good news. we just publish the DPS power supply module ( DPS3003, DPS3005, DPS 5005 and DPS 3012) this is the link www.aliexpress.com/store/group/DPS-Programmble-control-power-supply/923042_508466030.html DPS series is updated version, it updates some function and measurement range is increasing, especially DPS 30V12 ( current is 12A)hz.aliexpress.com/store/923042 you can check ..
Hi, thanks for sharing the info! Do you know you could series connect 2 of those to get a negative/positive power supply? Could not find any info on that or any datasheet.
hi, gr8 review, cud u pls tel wethr i can use it for supplying power to my lap top externally by using rechrg batteries, as the internal battery is dead and not available
To be honest, I'd much prefer a lab power supply with nice big analog gauges and one dial per parameter. Is space that expensive in NZ? Just kidding ;) Would probably be more expensive, obviously
Because I'm not a pro and this is a 'first look' as the title says, not a test or review. The voltage is very accurate, not sure if I ever checked current accuracy.
Is the output on this floating? I'd like to hook up two of these to the same power source to create a dual channel supply where I can hook the positive of one of the outputs to the negative of the other output so I can do -V/Common/+V for running op amps, but the supplies need to be floating for this to work. Thanks!
can I connect 11.1 volt lipo battery and get out 54 volts ? I connecting 4 led strips to 11.1 volt lipo and power is to low to get them to be very bright if I connect 2 x 11.1 volt lipo they are very bright but wires getting very hot after short time trying to find solution or boosting power from 11.1 or reducing, What you think ?
hey how about a new video showing it operate a 775 at .17 amps and 12 volts. that is the level of the 775 motor and i want to see or here from you that it will work so i can take apart a 20 amp and 12 volt tractor yanmar (permanent magnet alternator) and then attach the magnet to the motor rotate and the put it near the receiving coil to get the energy without a tractor motor i here all the country people who own radrunner are doing and that it extend the one hour battery to 72 hours of charge and they use them for herding animals but they have issues with not having shocks. they get back issues. oooowwwwwww. but if it goes that low then anything that can carry the extra weight goes forever. someone other motor willl break and the 775 so open body and attach fans like it is an alternator have been suggested.
Probably a dumb question but I’ll ask it anyway. I have a solar panel with variable output, that I want to use to power a device that has a minimum requirement, and gets fussy if it gets less than what it needs. Could I use this device to set output parameters for my device, so that it never receives less than 8V or less than 1A? If the solar panel can’t meet either of those requirements because of the light levels I’d like this controller to just switch off the output and wait until those levels can be met. Is that possible???
It doesn't really sound like a suitable thing for that purpose. No ability to get it to switch off at a certain input voltage at least. Usually things using solar will have a battery between them as a buffer, which the solar can charge when sunny, and the end-user device can still use when not sunny. Only problem is, you then need a circuit between the solar panel and battery so that the battery doesn't simply try to 'power' the panel when not sunny... I've never tried it myself but I have seen that it's not trivial.
Just as "i" is the symbol for current and [A] is its unit, 'u' is the symbol for EMF (sic. voltage) and [V] is its unit. It is one of those quantities where people tend to use "u" and "v" interchangeably, but the correct and unambiguous notation would be to use "u" like the manufacturer has used here. To be sure, for DC EMF, the symbol would be a capitalized "U" (again, they've used this correctly). Finally, someone who got it right :) . If you feel like arguing: "But why be so pedantic, and use 'EMF' instead of 'voltage'?" ask yourself this - How much 'amperage' do you charge your LiPo with? gah! "Current" sounds so much nicer...
In other words; U is "voltage", not "volts". I is "current", not amperes. Etc.
It depends. It's the SI-system. As I know USA still use gallons, miles, inches and probably V and E too. At least for some time ago.
It's a cool table for SI-parameters for electromagnetism a little donw this wikipage.
en.wikipedia.org/wiki/Electromagnetism
Aditya Mehendale why on U.K. Test certification is v denoted as u on ac systems and Uo as measured voltage on the supply characteristics page
I have no clue if the U.K. test-certification is consistent in its nomenclature. The SI is. They use V as the symbol for electric potential (and not U). As I said earlier, people tend to use it interchangeably. In mainland Europe, for example, the word for this electrical quantity roughly translates to "tension" - not the kind of tension you'd get in a spring, but rather there is a separate word, also used for e.g. social tension, perhaps used similarly to the English "high-tension-cable" (I know that the cable-analogy is bad, since a high tension cable actually refers to its elastic tension.). That being said, any EE would understand what you meant if you consistently used either V or U as a symbol for electric potential. The down-side to using "V" is that the symbol for the unit is exactly the same "V". This makes an (in?)equality like "V = 12V" give me the creeps. In any case, I'd recommend NOT using the symbol E. This is used categorically and universally to denote the electric-field, with a unit volt-per-meter (V/m) [which is the same as newton per coulomb N/C].
Aditya Mehendale rather than I = 5amps where as v can often stay as a constant measurement and unit I understand not fully grasping the cable elasticity thing but I'm not electronic so much as electrical if that that makes sense I guess in the long haul it doesn't really matter as long as you know not to earth it or short it your ok
U is symbol for voltage and it is measured in Volts -> U = 5V
I is symbol for current and it is measured in Amps -> I = 2A
Ohms Law is normally written as U = R * I
OVP, OCP, OPP are abbreviation so they use V/C/P instead for symbol used in physics expressions.
Be carefully with those protections. Depending on device it may be only hard limit, it may shutdown or clamp input. The last option with no protection on input may ruin your day (although it seems that this meter simply power down).
Thanks for review, I was thinking that I get this device and now I know that I want it :)
The answer to your question regarding the Letter U - That's us scot's fault, now adopted across Europe. Traditionally quantity (here voltage) and its unit (volts) are kept separate, which means using different characters for either:
current (I) is measured in amperes (A) and resistance (R) is measured in ohms (the upper-case omega). Having V to mean both quantity and unit sort of violates the spirit. So we use U to denote quantity.
V in our Europe is for Velocity. Letter U is for Unterschied which means "difference" in German like potential difference. And also at that time they ran out of letters for physical properties.
U is pretty common in Europe.
I've been taught U=R*I.
Same. R is meaused in Ω, I is measured in A, and U is measured in V.
I must admit. U i have not heard of. At uni, our calcs were, I =E/R current, Electromotive force, Resistance. I would say the U is a typo in the translation. U is not a standard abreviation on the IEEE standards
Seems like U as a symbol for Voltage came from the latin word urgere. Also atleast in germany we have our own standard organisation for electronics stuff (VDE) which is often used which specifies U.
In the UK we still use V for voltage at school and for more advance courses an epsilon (Ɛ). I think at university we used an uppercase epsilon for DC voltage and lowercase for AC voltage, but that was over 10 years ago for me.
just to sort this out with an update. V is the symbol for voltage. ie, 2.5V. when making a calculation U is used because it is the outcome of a voltage/current or whatever calculation. my research has uncovered that the use of "U" is not a direct unit of voltage. The IEEE have confirmed this. I must admit, i didnt know this myself until it came up in the Video. V =voltage. U is used to indicate the result of a calculation in which voltage is one of the constants.
The overvolt protection 'normally' works by clamping the DC input short circuit if overvolt is detected.
This might damage the DC supply, but save the DUT.
Put a fuse inline with your battery pack please!
Note: I suspect that your regulator/PSU may just open circuit the output, guess it is up to you to test.
NoName He doesn't need a fuse for testing purposes, the circuit has adequate protection, unless your anal, then use a fuse!
I have 2 of these now. I love them I power them each from a lenovo laptop power supply (20 volt 4.5 Amp) and can use for 2 independent supplies or a +/- rail configuration. Have had no issues so far and the current and voltage displayed is spot on from my external metering.
Good to hear. Yeah I was thinking to power this from a retired laptop power brick too.
That is the best option as they are isolated and will let you operate in serial ( 2x voltage) or back to back for a +/- supply. I haver a boatload of lenovo laptop bricks from work.
Hi friends.
there is good news. we just publish the DPS power supply module ( DPS3003, DPS3005, DPS 5005 and DPS 3012)
this is the link www.aliexpress.com/store/group/DPS-Programmble-control-power-supply/923042_508466030.html
DPS series is updated version, it updates some function and measurement
range is increasing, especially DPS 30V12 ( current is 12A)hz.aliexpress.com/store/923042
you can check ..
Where can we find info on what is updated/changed/improved?
DPS series are updated version. Panel is
different. In DPS series, we change the M1/↑and M2/↓ into V/↑and A/↓. You can
press those button set the voltage and current fast. We add a new function “set
default boot open or close output”
Others are not changed..
DPS5005
still need diode to charge the battery.
U is the letter used in physics for energy potential which is relative to some other potential, this difference is measured in Volts which is derived from the potential energy needed to move charge based on Newtons as a measure of power and so on. In English U is voltage and measured in V which is volts which makes the definitions muddy. In other languages these are sometimes separated by calling U for example potential or something else which is measured in volts (V). You can't increase volt (V) no more than you can increase a meter but you can increase voltage (U) just as you can increase distance which is then measured in V, it's a fairly subtle difference but an important one.
In Germany voltage always gets named U.
Uin - Uout - Udiff etc.
U=R*I
Why it's that way is pretty much unknown and very much limited to Germany. Some say it comes from latin "urgere" (drive, push)
Distortionize is ohm law where U (voltage) = I (corrent)× R (resistance)
Someone needs to send one of these into Dave EEVblog lol...He would love this....
haha ua-cam.com/video/Cw2AjcczHg4/v-deo.html
In Austria we use U for Voltage I for Current and R for Resistance
u = voltage in general and v = Volt is the unit in which it is measured kg*m^2/s^3 *A
just like I stands for current and A is the unit of measurement for current (I) ;-)
The S-OVP, S-OCP, S-OPP are for the power source i suppose. If you have a power supply that is 50V, 2A to power this regulator you can set these values so it won't overload if it is unprotected. Pretty nice feature to have for diy projects i must say.
That power supply is awesome for the price. Looks like a good power supply for someone like me who has very little electronics experience.
That was a great video , I’ just purchased the same. Looking device from eBay for $75 it has a higher output of 20 amps I intend to use it for some projects that run multiple large stepper motors
V is the (ISO) unit (Volt) of tension, U is the letter for the physical dimension (same as A stands for the unit of Ampere and I for the dimension of current).
Not sure if in the US you use V also for the dimension, but as it is an ISO unit, you shouldn't.
Interesting little module, now just to get a 3D printed case with an external cooling fan on back with banana plugs on the front bottom under the display for power output out of the front. Pretty cool it has the CC/CV and protections cutouts built in. Not bad for $30, too bad it's not a boost/buck converter where you can feed it in 12vdc from an old busted 300~+ watt ATX power supply, have it be able to step up to 50~vdc or all the way down to it's minimum, right now it just looks like it is a buck converter and you must supply more input voltage than output voltage.
Either way...pretty interesting little module, thanks for the review
God I love your modesty. UA-cam, especially from down under, has become a pit of writhing egos. Care on man.
I have this module and the 50v 20A version, I use it to charge 18650's, no need to use the diode just always connect and disconnect with the output turned on with the current limit set low, the diode will have a voltage drop so the output voltage will be less than on the display.
Well done! Your explanation showing CV vs CC modes was nice. A test with an LED strip would also show how CC mode can be used to control the LED brightness. Thanks for the video!!
PS: I have always used V to describe voltage and E to describe electromotive force.
bought one even before this video ended. hopefully it will hold up - but seems like a great value & i'll find it very useful in some of my projects not only w/ Arduino, but with high-power LED's. thanks for this - you are an experimenter after my own heart! found you after watching iNav vids.
Russ from Coral Springs, FL, USA
if you want to buy high power? we are designing DP30v/12A module . you can keep eye on my shop hz.aliexpress.com/store/923042
Hi friends.
there is good news. we just publish the DPS power supply module ( DPS3003, DPS3005, DPS 5005 and DPS 3012)
this is the link www.aliexpress.com/store/group/DPS-Programmble-control-power-supply/923042_508466030.html
DPS series is updated version, it updates some function and measurement
range is increasing, especially DPS 30V12 ( current is 12A)hz.aliexpress.com/store/923042
you can check ..
i have been using this 505v for some time now and really like it. i just gave mine away to my granddaughter who is very interested in learning all things Arduino (and eventually flying quads)... i'm not even all the way home (from Portand Maine to Coral Springs Florida) and i'm missing my supply/meter so much that i'm now ordering the DPS5015. nice unit!
Russ from Coral Springs, Fl usa
About the U as volts, here in Norway we use U as volts, R for resistance and i for ampere.
don't remember why we use U as volts since we only use URI in ohm's law at school where you use VRI?
and I have never seen U instead of volt in real life outside school (working as a mechanic last 7 years)
I HAVE built a simple digital automatic 18650 3s charger last night. Esp8266 n oled are being used.
OPP, you know me! too funny, I started thinking the same thing when u were talking about OCP...lol
the constant current fuction can realize OCP. This one has CC mode. it can protect module ..
Small, neat & I guess accurate; but unless you use regularly the setting routines would prove a challenge. I notice that any tripping of a protection setting might easily go un-noticed; maybe a flashing indicator would help?
yes, the silent tripping of a limit has got me many times...
The problem with this unit is simply that it is really involved to set the parameters for a data set, then saving.
The instructions are very poorly laid out so initially at least it's quite demanding.
The instructions (for example) refer to a potentiometer not the rotary encoder which it is.
Ideally this should couple via SW to a PC & enable much faster & more reliable programming.
In school I was told the formula to calculate the power usage P=UxI (Power=voltage X amperage). This is ohm's law I always hated that formula and always wrote it down as W=VxA and got in a couple of arguments with my teacher. more than 10 years later, I saw that teacher in a supermarket, and he still remembered me. He told me I was one of the few students that actually cared about what he was teaching. And that he mist the arguments in class after I drop his course and went on with metalworking the next year. I stilt think of that teacher every time I use ohm's law
I wish they could make one with a bigger screen size,
I have one of the 50v 15 amp ones, very happy with it
U is also used for voltage in France !
U, I and P is the SI-system's symbols for voltage (V), current (A) and power (W). So it's probably intentional. However, thanks for this video. One is on the way ;) If the maximum current can be preset, this unit will be perfect for powering high power laser diodes (which are current hungry, but easily destroyed at just a little overcurrent).
Interesting! Came across it as well.. Thanks for sharing this! :) Damn.. glad to see that loose wire didn't short something out :|
Handy pandy thing by the looks of it :D
What I want to see is someone putting a 100W load on it and hooking it up to a scope to see just how much the output oscillates. The last Chinese bench supply I tested was going almost 1V peak to peak under load.
I bought one of these not long ago and use it all the time. I only wish when you push the button to change voltage or current that it would stay in the change mode until I push the button again to end or even better, have an option in the settings to have it work that way or the default way which is automatically exit the change mode after 10 or 15 seconds or no input. When I am experimenting and want to play with voltage and/or current it is annoying to have it exit change mode by itself so I have to push the volt or current button again then push the knob two or three times to get to the digit I want to change... wash, rinse, repeat.... Also, interesting that the manual calls it the coding potentiometer since, as you mentioned, it is not a potentiometer but then no surprise from a translated document.
I bought another one more recently that has the feature you mention, where the voltage changing mode stays until you turn it off. It's a larger power one though, so not sure if they have made this modification to the lower spec ones as well:
ua-cam.com/video/siZTPRpyVrM/v-deo.html
@@iforce2d Hear that? It's the sound of slightly less than $40 leaving my wallet...LOL
I got the 30V 5A version, because it was half the price of the 50V model and I am only running it off 24V
Pretty neat device. It would be cool if it would have some data logging, or at least serial output with current voltage and current being drawn. The screen refresh is pretty low, at about 1-2Hz. I assume the protection mechanisms are implemented in software, and not using dac and comparators that triggers something. (other than current limiting I assume), which might be a bit unsafe. It most likely will deliver more current or power for about half a second, than what is set in settings, so still be careful.
Any ideas about turnup / turndown behavior, noise, ripple and load regulation.
Well, it's been a year since the release of the video. Is this neat gadget still performing OK? Would you recommend it for a hobby-class variable power supply?
Good review, going to get some of these for test kit at work off the back of this.
Voltage is noted with both V or U. Thanks for the video.
Great review for me, this unit is going straight into my cheap QJE PS3005 30v 5a supply. Thanks :)
Just wanted to say nice job on all of your videos. Keep up the gear work
Thankyou!
Late but hell just found this vid. U is potential energy, V(volt) is unit of measure of electrical potential. In electrical just kinda became voltage or just volts, as well but not as much I=current some times is referred to amperage or just amps.
lol, gotta love when you overlook the simple stuff
In Croatia we always used U for voltage and I for current. I=U/R
2:00 the input voltage is 6-55V but there is no indication of an input current.
Does it even matter because it will draw as much current as needed?
And also, what should the min. input current be?
btw. great video.
EDIT: I researched a bit and as I thought, it depends on how much current you use and there's is a way to calculate it if you know the efficiency.
in lithuania we use U for voltage
I was taught E=IR for Ohm's Law.
Thanks for posting this! I ordered one from Amazon!
Thanks for sharing. I've been eyeing these lately. I have some higher voltage power adapters floating around, plus some 40 volt lithium batteries for lawn equipment. Would probably work out quite well.
if you want charge battery? it can charge the battery , but it need a diode. and when you buy this , the diode will be in the package. 40v lithium batteries is ok. input voltage is max 55v..
don;t worry , you can try hz.aliexpress.com/store/product/RD-DP50V5A-Constant-Voltage-current-Step-down-Programmable-Power-Supply-module-buck-Voltage-converter-color-LCD/923042_32596330856.html
I am wanting to build a case for this unit and was curious if I could wire the diode into the circuit all of the time or should it only be used when charging batteries? Any problem with leaving it installed all of the time?
Hi friend
good, you can add it what you want. about the diode, only when you charge the battery, you can wire the diode, understand ?
Texas Ace
If you put it in a case, you can easily wire a switch in the output that would change between diode and non diode output. It wouldn't take much effort to make that work.
Thats a good ideal, had no thought of a switch. I ended up just putting 2 sets of power jacks on it, 1 directly connected and the other run through the diode. Figured that having 2 outputs would not be the worst thing around anyways.
Although for some reason I forgot that it is only a buck supply, so now I am on the hunt for a higher voltage power supply instead of an ATX PS. Think the best I have found is a 48v / A supply for $25ish, or since I doubt I will need that much power I might just go with the 3A version for $15.
Still should come out to around $50 all said and done for a 50v/5A adjustable power supply, not bad at all.
I'm planning to order one, really nice video. Thank you.
Thats the same case az the freq counter / tak units I uzed in my car. Kinda funny that they stuffed all that in there insted uv making a bigger case.
U = voltage I= current R= resistance first thing you learn in school just basic.
We learned the same with k,p,x
J IJzer Went to Naval Electronics Core school and we never used U. Instead we used E.
E (for electromotive force) is what we were taught in electrician school.
me too!!!
J IJzer I received my electrical engineering degree in the 80’s and we were taught E=I x R. .E = voltage or electromotive force. They eventually changed to V. New engineers i meet in the field use V., but i still use E. I have personally never heard U used. I have worked with Engineers all over the world, but never heard them use U for Voltage. New to me. I’m not denying it, i have just never heard of it.
I think you are confusing voltage (across a component) which is often noted as "U" and electric potential of a node, which is often noted "V". U across the component between nodes A and B is equal to V at point B minus V at point A...
U = the abbrevation for Voltage
V = the unit for voltage
250 Watts!
I have a 2 channel 150W Mastec that's 10 times the size of that thing that I paid $200 for.
Wondering if I should replace it with 2 of these?
That thing however is only the controller, you still need a DC Power supply to attach that to.
One that can output 40v at 6/7A
U is voltage, 1 V is a unit of voltage - pretty big difference here.
Depends on which book/source, it used to be U more often in books and such I believe. U=12v or V=12v ... I think U is a bit more sensible also.
Where does the U come from?
+iforce2d It's a european thing, that I know. But I don't think the origin is quite clear, maybe it's only done to not have two v's in V=12v, or because U was unused. Also, Unterscheid is difference in german... who knows?
In Europe, or at least in Germany, we always use "U" for voltage. No idea why ;-)
U is the general abreviation for voltage :)
U= Voltage
I = Current
R = Resistance
U=R*I etc.
U is the potential difference and it is the correct symbol or letter to stand for electrical potential difference. The unit of U is Volt(s). The word " voltage" is an informal and wrong expression.
Very nice, I plan to combine something like this with an old ATX PSU to have strong cv rails and a variable output with these features. But I still have questions: what is the minimum output voltage and current?
opp yeah you know ME!.... liked that one, made me chuckle
Nice video test. For about $15 more aliexpress sells a Gophert power supply with its own power supply and a case. No including shipping. I would probably want that if I were to splurge on a this type of thing. It does not have that confusing u designation for voltage.
Gophert power supply , I know this , display is led display.. and it sells very expensive and it is very heavy.
in fact it isn't worth the price .. you can this module .. 50v/5a , high precision and small volume..
it is very worth.. hz.aliexpress.com/store/product/RD-DP50V5A-Constant-Voltage-current-Step-down-Programmable-Power-Supply-module-buck-Voltage-converter-color-LCD/923042_32596330856.html
The lock makes it so you can't accidently knock the knob and change the voltage
If you use this power supply to charge a battery, the manufacturer states you must add a diode in series to avoid back current destroying this module. I wonder if adequate protection would be there if you simply add a diode between the input and output +ve terminals, i.e cathode to the input and anode to the output? I remember when I built variable voltage/current power supplies around 30 years ago, this method got around the problem, otherwise damage always resulted when the battery voltage was higher than the power supply voltage. Otherwise if you just place a diode in the positive output leg, you're going to need to allow for a 0.6V drop across the diode and accuracy suffers. As the designer Glen Liu has been active here, I'd be interested in your comments.
Not sure if you missed it but at 3:24 I show the included diode, and a connection diagram given.
Yes, I did see that in the video. I don't think you understand what I'm actually asking. When charging batteries, each type has a recommended voltage they should be charged to, for example a 12V SLA = 13.8V. By placing a diode on the output you need to compensate for the 0.6V drop across the diode junction. While not difficult, it's one more thing you'd need to consider when possibly this isn't necessary if a reverse bypass diode is fitted? That's why I'm hoping the designer can clarify this as he's been here recently.
Correct, I don't see what you're asking. To be honest I didn't see any difference between the two scenarios in your first comment, ie. "a diode between the input and output +ve terminals" and "a diode in the positive output leg". Both of these sound the same and are what that given diagram looks like to me. I better let Glen answer...
There's a big difference between those 2x scenarios. I'd show you on a circuit diagram if it was easy to do so. When I state the input and output +ve terminals, I'm relating this to the input and output positive terminals of the module. A diode fitted between the positive output terminal and the load (battery) is the method recommended by the supplier, but this is not ideal when setting the exact voltage seen by the load as a silicon junction (diode) has a 0.6V drop that is not exactly linear at low currents.
I see, I think. But that makes even less sense to me. So for example in my video here where I'm powering the module from a 3S lipo, the cathode of the diode would be connected to the positive terminal of my lipo, and the anode would be connected to the (in this case) 5V output of the module? Under what circumstances would current ever flow through that diode? And how does this protect the module from current flowing back from the battery? There are plenty of quick sketch sharing sites around - let me know if I'm getting this wrong: sketch.io/render/sk-9bc212b02d9709cd0a4df5ce2beaa593.jpeg
Ohms law : I=U/R so yes you WERE sleeping in school!!! Lol
I have been servicing electrical equipment for over 60 years here in the UK, and never seen the U used to describe or identify voltage.
I just bought 1 of these but the 5015 witch is 50 volt 15 amp it comes with a driver and was $49 I am going to use an atx power supply to run it so should be good
Excellent video!
Thanks are you still happy with this? Have you tried charging Lithium batteries with it?
So alternating current would burn it out so you have to have a battery. So I can't use it on a small generator. I never liked batteries because they will run out of power in the end. But I have to get my scooter running. I'm sure these medicaid people will want me to check in with my new doctor once they get the new of where I live. Last time it took them almost 8 month to get me a new doctor. I moved on the day I got their paper work. Just could not be helped. Thank You Loader.
Are you still happy with it ? I'm planning to get one due to its neatness!
yup, it's working fine :)
Still good? I'm looking at one to build an adjustable power supply for a couple machines.
Still working i think ?!
Dont wanna spend 30$ for a 2 Month wonder
Yes still working.
btw there is a discount ATM at banggood for this one
AWESOME I need to power mine up remotely - and it needs to come ON - by default... I'm not there to press the button!
Help required! My instruction are in chinglish, spanglish and germish. What does "Please to not off turn, yes." mean?
Tayro Thinkingoutloud lol
I've heard the electric company charges us by the unit I think,
Excellent functional review !! Thanks !! ;) ;)
Can we use this to directly charge my MacBook, iPad and iPhone? Instead of using chargers that came in the box that plugs to 110v?
in Bosnia we use U for voltage
buen review, de ese modulo controlador de fuentes, muy completo
U = Electric Potential.
Voltage is potential difference (Ub-Ua)
Nice device!
Good review video. But for 30$ one can buy a complete ATX power supply capable of say 350W + ... Can be adapted/hacked to become a very good lab power supply with regulated outputs.
"can be adapted".... sure, you can say that about almost anything. Here you have a nice package ready to go.
Oh for sure ... I mean it is a elegant and ready to go solution, no doubt. I only wish the price could be lower ... when compared with say a massively made ATX PSU ... looks expensive, otherwise it's no doubt very nice and very practical . I was by no means criticizing your choice. I am thinking to get one of those also, just sayin' hey seem expensive tho ...
Yep, I definitely need one, I have a
HP power supply (19.5V 3.5A), and IDK is small and kawaii lol
I am the designer of this goods.
we have my own shop on aliexpress hz.aliexpress.com/store/product/RD-DP50V5A-Constant-Voltage-current-Step-down-Programmable-Power-Supply-module-buck-Voltage-converter-color-LCD/923042_32596330856.html
there are many other version. you can check
I have the DP30V5A but I-set and U-set are way off. When I-set is on 1.000A, it runs in CC at 0.900A !
Can I calibrate these values?
Hi friend
how you get 0.9. are you sure you get 0.900? our module max error 10mA, please use a better mulitmeter to compare . and our module can't be calibarted. because we don't need..
thank you
and Hi friends.
there is good news. we just publish the DPS power supply module ( DPS3003, DPS3005, DPS 5005 and DPS 3012)
this is the link www.aliexpress.com/store/group/DPS-Programmble-control-power-supply/923042_508466030.html
DPS series is updated version, it updates some function and measurement
range is increasing, especially DPS 30V12 ( current is 12A)hz.aliexpress.com/store/923042
you can check ..
It shows on the display of the DP30V5A not on multimeter: the DP30V5A show I-set op 1.000A and shows current of around 0.900A when going into CC mode
Hi friend，
could you send a picture to me , my email 1749808860@qq.com. or you can make video on youtube, and tell me the link
thank you
think U is just used to make a diference from IN voltage and OUT
Hi, thanks for sharing the info!
Do you know you could series connect 2 of those to get a negative/positive power supply?
Could not find any info on that or any datasheet.
nice Naughty by Nature reference haha
hi, gr8 review, cud u pls tel wethr i can use it for supplying power to my lap top externally by using rechrg batteries, as the internal battery is dead and not available
To be honest, I'd much prefer a lab power supply with nice big analog gauges and one dial per parameter. Is space that expensive in NZ? Just kidding ;) Would probably be more expensive, obviously
Why there were no tests under load? Why there were no tests with actual precise multimeter and comparison?
Because I'm not a pro and this is a 'first look' as the title says, not a test or review. The voltage is very accurate, not sure if I ever checked current accuracy.
Is the output on this floating? I'd like to hook up two of these to the same power source to create a dual channel supply where I can hook the positive of one of the outputs to the negative of the other output so I can do -V/Common/+V for running op amps, but the supplies need to be floating for this to work. Thanks!
is this the one use for voltage injection in repair motherboard?
what is the minimum current limit?
cause the LTC3780 is much cheaper but with no display and also the minimum current limit is 300mA
So helpful, thanks.
can I connect 11.1 volt lipo battery and get out 54 volts ?
I connecting 4 led strips to 11.1 volt lipo and power is to low to get them to be very bright if I connect 2 x 11.1 volt lipo they are very bright but wires getting very hot after short time trying to find solution or boosting power from 11.1 or reducing,
What you think ?
7-Segment Displays, cannot display "V" and uses "U" in place of V. But there was no need of using U instead of V here.
I have the DP30V5A but I-set and U-set are way off. When I-set is on 1.000A, it runs in CC at 0.900A !
Can I calibrate these values?
So combining it with a PC PSU to use on the bench?
It's only a buck converter so you can't get anything higher than 12 volts.
16:20 had me cracking up!
Nice explanation :) keep it up!
Can someone suggest a cheap case and fitting AC adapter for this ?
the stuff on the internet is so much fancier than the electronics store... why?
I have seen the these 10$ cheaper without the m1, set, and m2 buttons does anyone know what the difference is?
hey how about a new video showing it operate a 775 at .17 amps and 12 volts. that is the level of the 775 motor and i want to see or here from you that it will work so i can take apart a 20 amp and 12 volt tractor yanmar (permanent magnet alternator) and then attach the magnet to the motor rotate and the put it near the receiving coil to get the energy without a tractor motor i here all the country people who own radrunner are doing and that it extend the one hour battery to 72 hours of charge and they use them for herding animals but they have issues with not having shocks. they get back issues. oooowwwwwww. but if it goes that low then anything that can carry the extra weight goes forever. someone other motor willl break and the 775 so open body and attach fans like it is an alternator have been suggested.
Question does it have a protection for back feed into your battery or was that package needed?
I assume it doesn’t have it built in and that diode is needed for reverse protection
Probably a dumb question but I’ll ask it anyway.
I have a solar panel with variable output, that I want to use to power a device that has a minimum requirement, and gets fussy if it gets less than what it needs.
Could I use this device to set output parameters for my device, so that it never receives less than 8V or less than 1A? If the solar panel can’t meet either of those requirements because of the light levels I’d like this controller to just switch off the output and wait until those levels can be met. Is that possible???
It doesn't really sound like a suitable thing for that purpose. No ability to get it to switch off at a certain input voltage at least. Usually things using solar will have a battery between them as a buffer, which the solar can charge when sunny, and the end-user device can still use when not sunny. Only problem is, you then need a circuit between the solar panel and battery so that the battery doesn't simply try to 'power' the panel when not sunny... I've never tried it myself but I have seen that it's not trivial.
I have brought this stuff to bring down 40 volt voltage into 24 volt for my a e-cycle my a cyclist 24-volt 450 Watt motor