Thanks Mr. Pete. I'm 61 years old and have been a helicopter mechanic for 40 years so figuring out mechanical things is in my nature but you just taught me something that I've wondered about on a few occasions. Hopefully age will never prevent me from learning new things. Carry on please, sir!
From what I've seen over the years, there's not a lot of people who have ever even heard the click of the flasher because they NEVER use their turn signals!! P.S. Love the What Makes It Work series!
That little metal piece that bends with heat is called a bimetal. Two pieces of metal with different rates of heat/ expansion laminated together. When heated, one expands more than the other causing it to bend. Same technology used in the thermal trip side of most circuit breakers. Neat video Pete!
+Michael Murray "Bimetal" refers specifically to a strip made of two layers of different metals sandwiched together. While it is true that this is used in breakers, and thermostats, and many flashers, if you look closely you will see it is not the case here. The strip with the heating wire around it is spot welded on the two ends to the larger spring. As the strip heats it expands, causing the spring to click over. It just relies on the lengthwise expansion of the metal compared to the cold spring rather than bending from different expansion of dissimilar metals in a bimetal strip heated to the same temperature. The difference is subtle, but important.
Brings the feeling of those 1950's cars where the whole body was vibrating when the flashers were actuated, every piece of steel in those cars were welded solid together, so the KLUNK was really loud... My first memories were my dad's 1953 Pontiac... ;)
My daughter and I were working on replacing her flasher in her truck when you posted this video. Great timing, and yes girls also like watching your videos. Keep up the good work!
Hi my husband and l restored a 1948 bsa motorcycle it needed flashers we had no idea how a flasher worked, thanks to you we now have flashers on the old bike thanks again for the information cheers from Australia
I'll keep the idea of moving the flasher unit out from under the dash in mind. Tinitis and road noise won't let me hear them anymore. Too many hours on an old Cats with loose decking plates and un-muffled pony motors. As a young man, I spent a day running a series of errands with my Father. One task took us by where he worked at the rail yard. At the board marker's office he met one of his peers, Mr. Raymond "Ollie Dolly" (as the female clerks called him) Oliver. They hadn't seen each other for a while, so there was the usual greetings and exchange of news, part of that was about the recent influx of new 'kids' (switchmen) and how 'green' they were. Ollie asked: "Kenny, do you remember when we looked across the yardmaster's desk and thought 'when is this old prune-face going to retire?'" Dad nodded. "Now we are the prune-face." and now I are...
Great informative video. Loved your comments about the elderly Florida drivers. I'm there for the month and I agree with your observations completely. Lots of youthful aggressive drivers on the road too. I haven't decided which is worse.
I recall when Dad had to hang his arm out the window to signal!! ;-) For years, he did that even with the turn signal on. Thanks for sharing and bringing back some good memories!!
Thanks for another great video. I'd like to add that I solved the problem of not being able to hear the "click" by wiring a seat belt buzzer in series with the flasher thus making an intermittent "buzzing" sound. It was just obnoxious enough that I never again forgot to cancel my turn signal. :)
Nice video thank you- Im replacing the turn signal lamps to LEDs on my 61 Chev. This is why I have to also upgrade to a solid state flasher for LED as LEDs do not impose enough load to allow the mechanical fisher to work properly. This was a good refresher to remind me why this is necessary.
Nice video. I troubleshooted a similar flasher (turn signal relay) a few decades ago when my 1962 VW beetle was acting up. The flasher in my old VW even had an adjustment screw to adjust the on/off time ratio (IIRC).
Great video and thanks for making it. But, I think that at about six minutes into the video, you may have said it backwards. I think the heating element heats up when the contact is closed, and cools off when the contact is open. When the contact is open, no current can flow, and hence the heating element can't heat up.
+Physics Videos by Eugene Khutoryansky I think there are two different configurations and his various cut opened examples show both. BTW the older designs had three prongs. The heater circuit was somewhat separate. Missed his six minute explanation.
The old style flashers worked that way (like a thermostat) and started in the ON state but they had some shortcomings: 1. They had to be matched to the current of all the lamps to get the timing right. Say your car has 4 lamps per side - one lamp fails and now there's not enough current draw to heat the bi-metallic strip and open the contact. This lights stayed on and no flashing occurred. If you added a trailer so you now had 5 or 6 lamps per side, the higher current draw heated the strip too quickly and the flasher went too fast for the lamps to reach full brightness. 4 lamp flashers were very common; front, back, and 2 side markers. If a designer wanted to deviate from that he/she had to play with the lamp size to stay within the flasher's range or use a differently tuned flasher. 2. Making and tuning bi-metallic strip flashers was a bit fiddly and took skill to get them all flashing at the same rate like the designers wanted. To get around all that the bi-metallic strip was eliminated and a low current heater was connected across the terminals full time. Now the flasher could work with only 1 lamp or 10 - as long the circuit was completed the heater would operate. A spring steel snap acting switch replaced the bi-metallic strip. The switch is bent back away from the contacts and a small splint (lack of a better term) is attached to hold the contacts open. The heater coil is wrapped around this splint. These flashers start in the LAMP OFF state. The heater causes splint to expand allowing the spring contact to close and light the lamps. While closed, the heater is shorted and all the current goes to the lamps. When the splint cools it shrinks and pulls the contacts apart and repeats the cycle. Remember back when we'd manually flash the signals to make a lane change? The lights came on as soon as we nudged the lever as we had the old style flashers. Then somewhere along the line they no longer did that (new style flashers) and we had to hold the lever until it started flashing on it's own. This caused accidents as folks used to doing the quick flash were changing lanes not realizing the flasher hadn't started yet. I think it was around this time that many people stopped using flashers altogether as they couldn't be bothered to wait that 1 second for something to happen.
+Eddie the Grouch, in the particular example shown in this video, the flasher only has two terminals, and it is connected in series with the light bulb. Therefore, I think it has to be one of the old style flashers, as there is no way that the flasher, in this configuration, can simultaneously interrupt current flowing to the light bulb, and still have a closed loop for current to flow through the heating element.
+Physics Videos by Eugene Khutoryansky could the resistive heater be connected in parallel, passing current through the light but not enough to notably light the lamp?
The clue is in what state the flasher's switch is in un-powered. If the switch is closed, the heater is in series with the switch and merely replaces the function of a bi-metallic strip. All the lamp current must past through the heater and the total lamp current can effect the flash rate. I called this the "Olde Style" or type 1 flasher. If the switch starts in the open state (as in the close-up example), the heater is bridged across the terminals in parallel all the time. The high resistance heater only needs a small current to operate and itself passes only a small current to the lamps, not enough to light them, while the flasher switch is open. Once the heater operates and the switch closes, the heater stops because the current flows through the lower resistance path of the switch. The heater is effectively shorted out and ignored. This why the number of lamps has little effect on the flash rate. When the heated strip cools and retracts the switch, the current has to flow through just the heater again and the cycle repeats. This I call New Style or type 2 flashers.
The mother-in-law took her car in for the "flasher" to be fixed. It was but the clicking sound went away. She told the mechanic, with a very strict voice to put the clicking back again,...which he did. Nice video Mr. Pete
Another excellent how it works vid ! ! After seeing this I think I now know why the clicking cycle seems to speed up when you have a signal bulb burned out. The extra current not being used by the burned out bulb heats up the bi-metal quicker - with the extra current it quickens the cycle time.
I was just wondering about this - but I think this is not correct. This flasher acts as a switch, and the current flowing through it is defined by the resistance (the bulbs) and the voltage of the battery. If you take out one bulb, the current will be lower, because you have higher resistance for the same voltage, therefore the flasher will heat up slower. However, what I think really happens is, that the final temperature it reaches, before it turns on, is lower, just a bit over the switching limit, and so it cools down to the turn off limit in a shorter period of time. So the "temperature swing" is reduced, and so also the mechanical movement gets limited, and this results in a higher switching frequency.
MR. PETE, IT IS INTERESTING TO NOTE THAT LIONEL TRAINS USED THAT SAME METHOD TO BLINK LIGHTS ON SOME OF THE ACCESSORIES. IT WAS ALSO USED TO RING THE BELL IN SOME OF THE TENDERS. GREAT VIDEO, THANKS.,
Great video. The current flows through the heater element and completes the electrical circuit through the filament in the bulbs, however the heater element consumes just enough current to cause the heater element to heat up but not light up the bulbs. When the strip of metal flexes due to being heated it closes the contact points and gives the current a direct path to the bulbs causing the filaments to light up, at the same time the heater element cools down and the strip of metal relaxes and the contacts open and the cycle repeats itself. The reason that the flasher cycles faster when a bulb burns out is because there is LESS electrical resistance in in the circuit and the heater element heats up faster.
Why would be less resistance? The bulbs are conneced in parallel, if one of them falls out from the circuit, the resistance will be more and not less. The current will be less and not more.
The strip of metal he's referring to is a bi-metal. Two different metals are sandwiched together to form the strip. Each metal expands at a different rate, when current is applied, which causes the strip to flex...hence, opening the circuit. Once the strip cools off, it regains its original form (closing the circuit) and the process repeats.
MrPete222 as stated below, and as I understand it, the "spring steel" part is indeed a a Bi metal strip with a Kink (or bend) in it and when heated it expands deferentially (one side more than the other) and Clicks (AKA Oil canning) and disconnects the heater then after cooling it relaxes, clicks back again and reconnects the heater for another cycle. I hope i've gotten it right :-) thanks for all your "Classes" in Machining etc.
My only disappointment was when you disconnected the still-hot wires from the working flasher setup (4:51), and laid them down, they didn't touch each other and create the world's smallest fireworks show, as they most certainly would have done for me...your comments would have been fun. I'm a BIG fan, Pete, and always look forward to the email notice about your newest video being ready for viewing...thank you for being who you are, and for doing what you do.
@mark spencer I see this is an old comment of yours, but maybe you still will read my response. :) This went through my mind too, but in fact, only the light would be turned on, if the two leads had touched each other. So no fireworks, because that would not have been a short circuit. :)
Very nice! I have found out that the original General Motors flashers are irreplaceable. The aftermarket ones don't work the same and don't sound the same. Therefore, whenever I am at the junkyard, I collect original GM ones for my project cars.
the newer ones, newer than the thermal ones use a condenser. the condenser stores a charge but takes some time to be filled, once its filled the relay can switch to drain the condenser thru the tail lights, once the charge is drained the relay opens and power is then allowed to flow into the condenser which takes time to fill before energizing the relay and allowing the turn signal to light. these work good with incandescent bulbs but not so well with led bulbs, the interval is longer since led's take less power to light. also if a bulb burns out you have a slower flash rate. once thing i noticed is that when you turn on your 4 way flashers, the flash interval is somewhat faster.
This is awesome! I didn't know anything about this series, I thought you only made metalworking videos. If you get an FLIR attachment for your phone, you'll be able to see and record temperature changes such as this. Keep up the great work!
Nice video. I've been in and out of electronics since the early 1990's and was unaware of these thermal flashers. Simple concept though certainly, but very energy inefficient compared to digital technology. Well done video!
Really great explanation / demonstration. Any idea what can cause one of these to go bad? I had two go bad in the last month. My signals would just stay on all the time instead of flash
Great video Mr. Pete! Very enlightening for sure! Interesting, at 6:46 it looks like the soldered connection in the upper left is liquified! I know it can't be so it must be a trick of the eye, but it really looks like the solder is moving in liquid form.
The spring that changes shape is called a Bi-Metal spring. It is a sandwich of two layers of different metals. Different metals expand and contract at different rates and at different temperatures. When the element heats the spring, one side expands faster the other, causing it to warp.
You touched upon a good question; how does the complex turn single switch work? The opposite break light canceled by the turn single was a tough one to figure out.
+mrpete222 I actually wired in two, wired directly off the rear flashers. It was made easier with it being an estate. I also seldom have rear passengers to annoy ;-)
+mrpete222 That's all I did, cheap 12v buzzers from eBay, wired in series with the bulb. I left them behind the trim and they were still too loud so I wrapped a bit of foam round them. Been working for 5 years now.
Have you considered fitting a small buzzer tapped into the indicator output? many available on e-bay. Could use the simple buzzer and chewing gum approach to adjust volume - or a more sophisticated volume control using a variable resistor so you can set a comfortable level.
Very cool. Thanks for another great video Mr Pete. In your playlist for "What makes it work" there are 4 more videos that are [Private video], and therefore not viewable. Wasn't sure if you are aware of that. If you have 4 videos that aren't getting any views, that would be the reason. Don't misunderstand, this is total selfishness on my part. If you have made other videos, I want to see 'em!
The flasher is an auto resetting circuit breaker. The on time and off time are dependent on the current draw of the bulbs. A failed bulb reduces the current draw and alters the timing. Likewise, adding a bulb would have an opposite effect - towing a trailer for example.
Although your statement is correct, it does not explain why a failed bulb would increase the frequency of the flash. More bulbs = higher current. Higher current means the strip will expand quicker. This would imply an increase in frequency as more bulbs are added to the circuit. But, the opposite seems to be the case. As you reduce the number of bulbs it reduces the current, yet the frequency increases. This timing question has puzzled me for years.
+KevCarrico, current is the flow of electrons through a circuit and doesn't exist until it is being used/consumed by a load. There is no such thing as 'excess current' that is not being used. The bulb's filament is a load and current flows while it's connected to the battery. When the bulb's filament breaks there is no longer a path for the flow of elections and therefore no longer any current.
Great video! Thanks Tubal Cain! How about taking apart some circuit breakers. Maybe square D QO? I just replaced a bunch in a panel that was overheating from bad breakers.
Hrm, perhaps this explains why the turn signals on my old motorsickle just burn solid and won't flash. Either the relay is seized up or it isn't getting enough current to heat up sufficiently to cycle.
I really enjoyed watching this, and I have a question, I have a 78 gmc tiltwheel pickup, its been shall we say, upgraded to what ever fits the owner at the time, its rusty, but I had everything working well, Then the blower motor seized up, so I installed a new one, and it would not work, I had to hot wire it from the fuse box, and then found out the turn signals wont work, I checked bulbs, and wires, and put in a new switch, and still, they dont work, I have power going into the switch, and the 4 ways work, and running lights, and brake lights, but no power coming out of the switch, for turn signals?, I tried 3 different flashers as well, Ground? bulb?. why would both heater fan, and signals stop together?
I bought an aftermarket "loud" beeping flasher for my toyota tundra, but I wish I could find the "old school" style from the 60's that really sounded off with a double click. Anyone have any ideas to make the clicking louder??? Another Great video Mr Pete.
I must say I am enjoying your You Tube videos very much, especialy the 'how it works' ones. I always wondered about that coaster brake. Where could I find out about cutting multiple threads?
The color of the plastic shells (and the stripe on the aluminum shells) of the Wagner, Sylvania and Signal-Stat round flashers told you which model they were and what the load rating was. From the '60s through the mid-'90s, these thermal flashers were almost universally used among all U.S. car manufacturers. The color coding of the most commonly used ones during the '70s and later was: Green - # 552 (variable load used for hazard flashers - up to 6 27 watt bulbs, did not show lamp outage) Light blue - # 224 (fixed load for 2 27 watt bulbs) Gray - # 228 (fixed load for 2 27 watt bulbs plus a little extra, maybe a signal harness relay or higher wattage bulb like a 2357) Yellow - # 323 (fixed load for 3 27 watt bulbs) White - # 325 (fixed load for 3 27 watt bulbs plus a little extra) I miss the metallic click and the variation of flash speed of these old school flashers.
Great video! I was looking for an instructional video such as this one explaining how to wire everything. I have two questions for you. Can a 12v Heavy Duty Flasher 537 be used with two 12v LED lights? How would I wire them?
HI THERE,GOOD VIDEO',I HAVE THIS 1979 KAWASAKI KE 100 ENDURO,I REPLACED THE REGULAR SIX VOLT TURN SIGNALS WITH AN LED SIX VOLT TURN SIGNALS.WHEN I SWITCH TO THE LEFT,ALL 4 BULBS ARE FLASHING,SAME WAY TO THE RIGHT.WHERE DID I GO WRONG?PLEASE GIVE SOME ADVISE.THANK YOU
+mrpete222 Thanks for replying Mr. Pete -- My theory was the outside temperature would affect the heating & cooling speed of that metal strip, which would in turn change the blink frequency. So in the winter when the temperature was -30 outside, the metal strip would take longer to heat up and cool quicker which would mean the blinker would blink quicker and pause longer between blinks. The inverse would happen in the summer. I've done some poking around the internets, and from what I can tell there would be a change, but it would be very small, so not noticeable difference... Testing my theory would be a neat experiment though...
@@2121jwill Temperature dependence is small, because the switching happens due to the temperature difference between the heated and non heated part of the mechanics. So, in wintertime both will be at lower temperature and in summer both at higher temp. The electrical power for the heating will provide in both cases the same "delta T" (temperatur increase), thus the switching process will have the same (or very similar) flow.
Greetings, I have a question for you. I’m trying to make a DIY European style two-tone siren using car horns and need a flasher capable of handling the task. I’m using two Seineca horns, one at 335Hz (3.0 amps) and the second at 435Hz (3.0 amps). Any suggestions ?
When the contact point on the steel strip touches the stationary contact point (which closes the circuit to turn on the light), the heat accumulated in the steel strip drains through the contact point into the stationary piece of steel more quickly than heat accumulating in the heating coil, so the steel strip cools and returns to its previous position, thereby opening the circuit, and the cycle repeats. Also, I'm guessing the resistance through the heating coil is greater than the resistance through the bulb, so when the circuit is closed, the electricity prefers to flow through the bulb rather than through the heating coil, which also allows the coil to cool down. When both front and rear bulbs are ok, you get a nice slow repetition rate, but if one of the bulbs burns out, the repetition rate increases, because the resistance through the bulb pair increases (the bulbs are connected in parallel, and the resistance through one of the bulbs goes to infinity), so more current continues to flow through the heating coil, so it does not cool as thoroughly as when both bulbs are working, so it breaks electrical contact sooner, so you get more rapid cycling, which alerts you to the fact that one of the signal bulbs is out.
The key is, the current does not flow continually through the heating coil. The process is like this: The heating coil is permanently connected to the two outside connectors of the flasher. When the indicator light switch closes the circuit, the current starts to flow on the heater coil, but this is a relatively low current (say 100-200mA), which is not enough for the bulbs to light up. They have a relativeley low resistance (a few ohms), while the heater coil has a higher value (say around 50-150 ohms) to reach the mentioned current. So at first the heater coil starts to heat up, and the bulbs dont do anything. As the temperature of the small steel part is rising, it is expanding in length, and starts to bend the other larger part of the swithching mechanics. When the switching point is reached, the contacts are closed. At this point the heating coil is shorted by the contacts, so there will be no more voltage on the heating coil, and of course no more current either. This is the main reason why the heated part starts to cool down. Because there is no heat supply any more, to override or compensate the heat loss coming from the risen temperature. At the same time, as the contacts are closed, the bulbs are not "powered" through the high resistance of the heating coil, which was not enugh to power them up, but directly through the closed contacts with no resistance, and so the current starts to flow on a higher level according to the resistance of the bulbs. Then in the meantime the smaller steel part is cooling, and contracting, pulling the larger plate back. With decreasing temperature it will reach a point, where the increasing pulling force is enough to turn the larger plate back in the off position. And then the cycle starts all over again.
I've got a 3-prong thermal flasher, and just tried hooking it up to a 12v power supply. Smoke came off the tiny wire! I wondered if I had it wired backwards, so switched my wires around. Again, more smoke, and still no clicking. Any thoughts on what I am doing wrong? I don't seem to have burned anything out yet, but I think I am close. Smoke is never good.
Thanks Mr. Pete. I'm 61 years old and have been a helicopter mechanic for 40 years so figuring out mechanical things is in my nature but you just taught me something that I've wondered about on a few occasions. Hopefully age will never prevent me from learning new things. Carry on please, sir!
You must be 65 now, how are you doing sir
From what I've seen over the years, there's not a lot of people who have ever even heard the click of the flasher because they NEVER use their turn signals!!
P.S. Love the What Makes It Work series!
+suzukichopper LOL--thats the best one yet--Thanks for watching
bmw
Lol bulb savers
That little metal piece that bends with heat is called a bimetal. Two pieces of metal with different rates of heat/ expansion laminated together. When heated, one expands more than the other causing it to bend. Same technology used in the thermal trip side of most circuit breakers. Neat video Pete!
+Michael Murray "Bimetal" refers specifically to a strip made of two layers of different metals sandwiched together. While it is true that this is used in breakers, and thermostats, and many flashers, if you look closely you will see it is not the case here.
The strip with the heating wire around it is spot welded on the two ends to the larger spring. As the strip heats it expands, causing the spring to click over. It just relies on the lengthwise expansion of the metal compared to the cold spring rather than bending from different expansion of dissimilar metals in a bimetal strip heated to the same temperature.
The difference is subtle, but important.
+Michael Murray Thanks for watching
+stefantrethan You are right on--not bimetal
Brings the feeling of those 1950's cars where the whole body was vibrating when the flashers were actuated, every piece of steel in those cars were welded solid together, so the KLUNK was really loud... My first memories were my dad's 1953 Pontiac... ;)
My daughter and I were working on replacing her flasher in her truck when you posted this video. Great timing, and yes girls also like watching your videos. Keep up the good work!
One of those things you don't really ever think about how it operates... learned something new today... thanks.
Hi my husband and l restored a 1948 bsa motorcycle it needed flashers we had no idea how a flasher worked, thanks to you we now have flashers on the old bike thanks again for the information cheers from Australia
Wow what a fantastic video! This is how you make a proper video on how something works.
Thank you very much!
I'll keep the idea of moving the flasher unit out from under the dash in mind. Tinitis and road noise won't let me hear them anymore. Too many hours on an old Cats with loose decking plates and un-muffled pony motors.
As a young man, I spent a day running a series of errands with my Father. One task took us by where he worked at the rail yard. At the board marker's office he met one of his peers, Mr. Raymond "Ollie Dolly" (as the female clerks called him) Oliver. They hadn't seen each other for a while, so there was the usual greetings and exchange of news, part of that was about the recent influx of new 'kids' (switchmen) and how 'green' they were.
Ollie asked: "Kenny, do you remember when we looked across the yardmaster's desk and thought 'when is this old prune-face going to retire?'" Dad nodded.
"Now we are the prune-face."
and now I are...
Great informative video. Loved your comments about the elderly Florida drivers. I'm there for the month and I agree with your observations completely. Lots of youthful aggressive drivers on the road too. I haven't decided which is worse.
+eldoradony They are both bad
And another fine video class.
Thanks Mr. Tubalcain and to quote the famous teacher you are ..."So long for now"!
John
The old ways are still the best ways in my opinion. Great display and helped me with my 1971 HQ Monaro.
Thanks
I recall when Dad had to hang his arm out the window to signal!! ;-) For years, he did that even with the turn signal on. Thanks for sharing and bringing back some good memories!!
Thanks for another great video. I'd like to add that I solved the problem of not being able to hear the "click" by wiring a seat belt buzzer in series with the flasher thus making an intermittent "buzzing" sound. It was just obnoxious enough that I never again forgot to cancel my turn signal. :)
+Will Shankle good idea
Nice video thank you- Im replacing the turn signal lamps to LEDs on my 61 Chev. This is why I have to also upgrade to a solid state flasher for LED as LEDs do not impose enough load to allow the mechanical fisher to work properly. This was a good refresher to remind me why this is necessary.
Nice video. I troubleshooted a similar flasher (turn signal relay) a few decades ago when my 1962 VW beetle was acting up. The flasher in my old VW even had an adjustment screw to adjust the on/off time ratio (IIRC).
Great video and thanks for making it. But, I think that at about six minutes into the video, you may have said it backwards. I think the heating element heats up when the contact is closed, and cools off when the contact is open. When the contact is open, no current can flow, and hence the heating element can't heat up.
+Physics Videos by Eugene Khutoryansky
I think there are two different configurations and his various cut opened examples show both. BTW the older designs had three prongs. The heater circuit was somewhat separate. Missed his six minute explanation.
The old style flashers worked that way (like a thermostat) and started in the ON state but they had some shortcomings: 1. They had to be matched to the current of all the lamps to get the timing right. Say your car has 4 lamps per side - one lamp fails and now there's not enough current draw to heat the bi-metallic strip and open the contact. This lights stayed on and no flashing occurred. If you added a trailer so you now had 5 or 6 lamps per side, the higher current draw heated the strip too quickly and the flasher went too fast for the lamps to reach full brightness. 4 lamp flashers were very common; front, back, and 2 side markers. If a designer wanted to deviate from that he/she had to play with the lamp size to stay within the flasher's range or use a differently tuned flasher. 2. Making and tuning bi-metallic strip flashers was a bit fiddly and took skill to get them all flashing at the same rate like the designers wanted. To get around all that the bi-metallic strip was eliminated and a low current heater was connected across the terminals full time. Now the flasher could work with only 1 lamp or 10 - as long the circuit was completed the heater would operate. A spring steel snap acting switch replaced the bi-metallic strip. The switch is bent back away from the contacts and a small splint (lack of a better term) is attached to hold the contacts open. The heater coil is wrapped around this splint. These flashers start in the LAMP OFF state. The heater causes splint to expand allowing the spring contact to close and light the lamps. While closed, the heater is shorted and all the current goes to the lamps. When the splint cools it shrinks and pulls the contacts apart and repeats the cycle. Remember back when we'd manually flash the signals to make a lane change? The lights came on as soon as we nudged the lever as we had the old style flashers. Then somewhere along the line they no longer did that (new style flashers) and we had to hold the lever until it started flashing on it's own. This caused accidents as folks used to doing the quick flash were changing lanes not realizing the flasher hadn't started yet. I think it was around this time that many people stopped using flashers altogether as they couldn't be bothered to wait that 1 second for something to happen.
+Eddie the Grouch, in the particular example shown in this video, the flasher only has two terminals, and it is connected in series with the light bulb. Therefore, I think it has to be one of the old style flashers, as there is no way that the flasher, in this configuration, can simultaneously interrupt current flowing to the light bulb, and still have a closed loop for current to flow through the heating element.
+Physics Videos by Eugene Khutoryansky could the resistive heater be connected in parallel, passing current through the light but not enough to notably light the lamp?
The clue is in what state the flasher's switch is in un-powered. If the switch is closed, the heater is in series with the switch and merely replaces the function of a bi-metallic strip. All the lamp current must past through the heater and the total lamp current can effect the flash rate. I called this the "Olde Style" or type 1 flasher.
If the switch starts in the open state (as in the close-up example), the heater is bridged across the terminals in parallel all the time. The high resistance heater only needs a small current to operate and itself passes only a small current to the lamps, not enough to light them, while the flasher switch is open. Once the heater operates and the switch closes, the heater stops because the current flows through the lower resistance path of the switch. The heater is effectively shorted out and ignored. This why the number of lamps has little effect on the flash rate. When the heated strip cools and retracts the switch, the current has to flow through just the heater again and the cycle repeats. This I call New Style or type 2 flashers.
really enjoy the what makes it work series. Thank you Mr Pete.
The mother-in-law took her car in for the "flasher" to be fixed. It was but the clicking sound went away. She told the mechanic, with a very strict voice to put the clicking back again,...which he did. Nice video Mr. Pete
+Mike C. Good one
Pretty Neat!!! Never gave much thought about that annoying little switch lol Nice to finally see what is in there mystery solved Thanks !
This is an excellent series. Thank you for making them.
You're old. Yet you make a better video than most folks can produce! Seriously good work. Thank you #subscribed #sorryidrankwhiskey
Thanks
Wow! Great video! Thank you!!!
Glad you liked it!
Thank you! Great, thorough explanation and good quality visual representation.
Thanks
Always wondered how that worked. Thanks!
Pete....Like the way you explained and demonstrated...Great
Thank you
Beautiful. I love the level of detail in your film sir!
Thank you
Another excellent how it works vid ! ! After seeing this I think I now know why the clicking cycle seems to speed up when you have a signal bulb burned out. The extra current not being used by the burned out bulb heats up the bi-metal quicker - with the extra current it quickens the cycle time.
exactly
I was just wondering about this - but I think this is not correct. This flasher acts as a switch, and the current flowing through it is defined by the resistance (the bulbs) and the voltage of the battery. If you take out one bulb, the current will be lower, because you have higher resistance for the same voltage, therefore the flasher will heat up slower.
However, what I think really happens is, that the final temperature it reaches, before it turns on, is lower, just a bit over the switching limit, and so it cools down to the turn off limit in a shorter period of time. So the "temperature swing" is reduced, and so also the mechanical movement gets limited, and this results in a higher switching frequency.
MR. PETE, IT IS INTERESTING TO NOTE THAT LIONEL TRAINS USED THAT SAME METHOD TO BLINK LIGHTS ON SOME OF THE ACCESSORIES. IT WAS ALSO USED TO RING THE BELL IN SOME OF THE TENDERS. GREAT VIDEO, THANKS.,
+ROBERT HORNER Interesting--Thanks for watching!
Another title might have been 'What makes it tick'. Thanks for all your efforts, I've learned a lot.
+chuck fischer I like that. I just added it as a sub title. thanks
Great video.
The current flows through the heater element and completes the electrical circuit through the filament in the bulbs, however the heater element consumes just enough current to cause the heater element to heat up but not light up the bulbs. When the strip of metal flexes due to being heated it closes the contact points and gives the current a direct path to the bulbs causing the filaments to light up, at the same time the heater element cools down and the strip of metal relaxes and the contacts open and the cycle repeats itself.
The reason that the flasher cycles faster when a bulb burns out is because there is LESS electrical resistance in in the circuit and the heater element heats up faster.
Why would be less resistance? The bulbs are conneced in parallel, if one of them falls out from the circuit, the resistance will be more and not less. The current will be less and not more.
So interesting, Thanks!!
Great closeups. 👏🏻
Nice job, I'm enjoying this series. Thanks.
Thank you for teaching this old (well.....56 year old) man something he didn't know.
Great video
The strip of metal he's referring to is a bi-metal. Two different metals are sandwiched together to form the strip. Each metal expands at a different rate, when current is applied, which causes the strip to flex...hence, opening the circuit. Once the strip cools off, it regains its original form (closing the circuit) and the process repeats.
MrPete222 as stated below, and as I understand it, the "spring steel" part is indeed a a Bi metal strip with a Kink (or bend) in it and when heated it expands deferentially (one side more than the other) and Clicks (AKA Oil canning) and disconnects the heater then after cooling it relaxes, clicks back again and reconnects the heater for another cycle. I hope i've gotten it right :-) thanks for all your "Classes" in Machining etc.
My only disappointment was when you disconnected the still-hot wires from the working flasher setup (4:51), and laid them down, they didn't touch each other and create the world's smallest fireworks show, as they most certainly would have done for me...your comments would have been fun. I'm a BIG fan, Pete, and always look forward to the email notice about your newest video being ready for viewing...thank you for being who you are, and for doing what you do.
@mark spencer I see this is an old comment of yours, but maybe you still will read my response. :)
This went through my mind too, but in fact, only the light would be turned on, if the two leads had touched each other. So no fireworks, because that would not have been a short circuit. :)
What a great video! Thank you so much for making this. Very helpful and interesting
Very nice!
I have found out that the original General Motors flashers are irreplaceable. The aftermarket ones don't work the same and don't sound the same. Therefore, whenever I am at the junkyard, I collect original GM ones for my project cars.
+davida1hiwaaynet Thanks for watching--resourceful
I found that very interesting. Always wondered how that worked. Thanks for showing us!
the newer ones, newer than the thermal ones use a condenser. the condenser stores a charge but takes some time to be filled, once its filled the relay can switch to drain the condenser thru the tail lights, once the charge is drained the relay opens and power is then allowed to flow into the condenser which takes time to fill before energizing the relay and allowing the turn signal to light. these work good with incandescent bulbs but not so well with led bulbs, the interval is longer since led's take less power to light. also if a bulb burns out you have a slower flash rate. once thing i noticed is that when you turn on your 4 way flashers, the flash interval is somewhat faster.
This is awesome! I didn't know anything about this series, I thought you only made metalworking videos. If you get an FLIR attachment for your phone, you'll be able to see and record temperature changes such as this. Keep up the great work!
Thanks
I always wondered about it but finally looked it up. Very interesting. I always just thought the car sound system was playing the ticking!
Interesting!
Im amazed at how simple it is! back when you could actually understand how everything worked just by looking at it.
Excellent. Amazing what a little heat can do. Thanks for sharing. regards from the UK
+Gary C Thanks for watching
Excellent video.. Awesome work..! Clean and professional .. Thank you so much for the explanation ..
Sir you are the best teacher!. Thanks
😀😀😀
Like the way you explained it. Thank you
For some reason I really like the speed of the flasher at 8:48. Just like the ones in the older Chevy Colorados/GMC Canyons.
Nice video. I've been in and out of electronics since the early 1990's and was unaware of these thermal flashers. Simple concept though certainly, but very energy inefficient compared to digital technology. Well done video!
Thanks
Excellent video. I have a three prong flasher and was curious what the third prong is for.
Great explanation. Thank you! Can I wire something to my turn switch without turning off with the relay turning on and off (light blinking)
very helpful for me. putting turning light's on a motor cycle that never had them
Thanks sir, that was enlightening !
Keep on trucking (from France)
+MakeFix thanks for watching
Thank you a very helpful and informative video!
Thanks for the visual of the ROFs in FL.
Really great explanation / demonstration. Any idea what can cause one of these to go bad? I had two go bad in the last month. My signals would just stay on all the time instead of flash
Great video Mr. Pete! Very enlightening for sure!
Interesting, at 6:46 it looks like the soldered connection in the upper left is liquified! I know it can't be so it must be a trick of the eye, but it really looks like the solder is moving in liquid form.
+ShysterLawyer Ha, it really does look just like that.
In HD you can see it's just a reflection and the wire is actually spot welded there.
+ShysterLawyer Thanks for watching
explained in great detail as always.. thanks for sharing sir....
+Kevin Willis Thanks for watching
The spring that changes shape is called a Bi-Metal spring. It is a sandwich of two layers of different metals. Different metals expand and contract at different rates and at different temperatures. When the element heats the spring, one side expands faster the other, causing it to warp.
This is SO FASCINATING
Cool, now I know what that little tunk noise is with the blinker on! Thanks!
You touched upon a good question; how does the complex turn single switch work? The opposite break light canceled by the turn single was a tough one to figure out.
Great explaination Mr. Pete!
Mr Pete, I too can't hear the damn thing so I wired in a small 12v buzzer. Works a treat!
+Peter Fletcher I need to do that. But cannot even find the flasher on my new car-it is behind the speedometer in a tight spot
+mrpete222 I actually wired in two, wired directly off the rear flashers. It was made easier with it being an estate. I also seldom have rear passengers to annoy ;-)
+Peter Fletcher Can I tap into the tailight wires, instead of the actual flasher? Also, what kind of buzzer.
+mrpete222 That's all I did, cheap 12v buzzers from eBay, wired in series with the bulb. I left them behind the trim and they were still too loud so I wrapped a bit of foam round them. Been working for 5 years now.
Have you considered fitting a small buzzer tapped into the indicator output? many available on e-bay.
Could use the simple buzzer and chewing gum approach to adjust volume - or a more sophisticated volume control using a variable resistor so you can set a comfortable level.
Wonderful video thank you Pete
Great video and education... Thanks!
great video!! I use this video to show my Diesel Technology electrical class. thank you!!
Thanks
An interesting explanation. Thank you
Thanks
Very cool. Thanks for another great video Mr Pete. In your playlist for "What makes it work" there are 4 more videos that are [Private video], and therefore not viewable. Wasn't sure if you are aware of that. If you have 4 videos that aren't getting any views, that would be the reason. Don't misunderstand, this is total selfishness on my part. If you have made other videos, I want to see 'em!
Great video ,very detailed 👍👍
Thanks
Very informative and helpful!
Thanks
What makes it tick in double time if one of your bulbs is burnt out?
Thanks for the videos.
The flasher is an auto resetting circuit breaker. The on time and off time are dependent on the current draw of the bulbs. A failed bulb reduces the current draw and alters the timing. Likewise, adding a bulb would have an opposite effect - towing a trailer for example.
+Danny Morehouse Very well stated. I added your comment to the video at 5:35. thanks
Although your statement is correct, it does not explain why a failed bulb would increase the frequency of the flash. More bulbs = higher current. Higher current means the strip will expand quicker. This would imply an increase in frequency as more bulbs are added to the circuit. But, the opposite seems to be the case. As you reduce the number of bulbs it reduces the current, yet the frequency increases. This timing question has puzzled me for years.
excess current no longer used/needed by a blown-out bulb accelerates the blinker heating/cooling cycle.
+KevCarrico, current is the flow of electrons through a circuit and doesn't exist until it is being used/consumed by a load. There is no such thing as 'excess current' that is not being used. The bulb's filament is a load and current flows while it's connected to the battery. When the bulb's filament breaks there is no longer a path for the flow of elections and therefore no longer any current.
Great video! Thanks Tubal Cain! How about taking apart some circuit breakers. Maybe square D QO? I just replaced a bunch in a panel that was overheating from bad breakers.
+CRANEDRUMS Believe it or not, breakers are on my to do list.. I'm so cheap, that I'm watch for used ones
Nicely done!
Hrm, perhaps this explains why the turn signals on my old motorsickle just burn solid and won't flash. Either the relay is seized up or it isn't getting enough current to heat up sufficiently to cycle.
Wow I was curious about these! Thanks for this clear explanation. K.
I really enjoyed watching this, and I have a question, I have a 78 gmc tiltwheel pickup, its been shall we say, upgraded to what ever fits the owner at the time, its rusty, but I had everything working well, Then the blower motor seized up, so I installed a new one, and it would not work, I had to hot wire it from the fuse box, and then found out the turn signals wont work, I checked bulbs, and wires, and put in a new switch, and still, they dont work, I have power going into the switch, and the 4 ways work, and running lights, and brake lights, but no power coming out of the switch, for turn signals?, I tried 3 different flashers as well, Ground? bulb?. why would both heater fan, and signals stop together?
didnt expect that subject ,-but it was interesting!thx man.
pretty cool Thanks for Sharing!!!
I bought an aftermarket "loud" beeping flasher for my toyota tundra, but I wish I could find the "old school" style from the 60's that really sounded off with a double click. Anyone have any ideas to make the clicking louder??? Another Great video Mr Pete.
+GunPilot Thanks for watching
I must say I am enjoying your You Tube videos very much, especialy the 'how it works' ones. I always wondered about that coaster brake. Where could I find out about cutting multiple threads?
+Rusty Stebbins He's covered that, just look back through his other videos...
The color of the plastic shells (and the stripe on the aluminum shells) of the Wagner, Sylvania and Signal-Stat round flashers told you which model they were and what the load rating was. From the '60s through the mid-'90s, these thermal flashers were almost universally used among all U.S. car manufacturers. The color coding of the most commonly used ones during the '70s and later was:
Green - # 552 (variable load used for hazard flashers - up to 6 27 watt bulbs, did not show lamp outage)
Light blue - # 224 (fixed load for 2 27 watt bulbs)
Gray - # 228 (fixed load for 2 27 watt bulbs plus a little extra, maybe a signal harness relay or higher wattage bulb like a 2357)
Yellow - # 323 (fixed load for 3 27 watt bulbs)
White - # 325 (fixed load for 3 27 watt bulbs plus a little extra)
I miss the metallic click and the variation of flash speed of these old school flashers.
Thanks for teaching me.
Great video! I was looking for an instructional video such as this one explaining how to wire everything. I have two questions for you. Can a 12v Heavy Duty Flasher 537 be used with two 12v LED lights? How would I wire them?
HI THERE,GOOD VIDEO',I HAVE THIS 1979 KAWASAKI KE 100 ENDURO,I REPLACED THE REGULAR SIX VOLT TURN SIGNALS WITH AN LED SIX VOLT TURN SIGNALS.WHEN I SWITCH TO THE LEFT,ALL 4 BULBS ARE FLASHING,SAME WAY TO THE RIGHT.WHERE DID I GO WRONG?PLEASE GIVE SOME ADVISE.THANK YOU
Thanks Mr Pete
LOL -- men in florida, flashers and the "early bird special"!!!
Thanks a lot, keep them coming.
Mr Pete that was great
+Doug Van Allen thanks for watching
I was very surprised blinkers worked that way! So, does that mean blinkers would blink at different rates in the winter v.s. the summer?
+Jack Williams ???--Thanks for watching!
+mrpete222 Thanks for replying Mr. Pete -- My theory was the outside temperature would affect the heating & cooling speed of that metal strip, which would in turn change the blink frequency. So in the winter when the temperature was -30 outside, the metal strip would take longer to heat up and cool quicker which would mean the blinker would blink quicker and pause longer between blinks. The inverse would happen in the summer.
I've done some poking around the internets, and from what I can tell there would be a change, but it would be very small, so not noticeable difference... Testing my theory would be a neat experiment though...
@@2121jwill Temperature dependence is small, because the switching happens due to the temperature difference between the heated and non heated part of the mechanics. So, in wintertime both will be at lower temperature and in summer both at higher temp. The electrical power for the heating will provide in both cases the same "delta T" (temperatur increase), thus the switching process will have the same (or very similar) flow.
Greetings, I have a question for you. I’m trying to make a DIY European style two-tone siren using car horns and need a flasher capable of handling the task. I’m using two Seineca horns, one at 335Hz (3.0 amps) and the second at 435Hz (3.0 amps). Any suggestions ?
But I'm trying to undertand: why would the steel strip ever cool off if the current keeps flowing continually into it?
When the contact point on the steel strip touches the stationary contact point (which closes the circuit to turn on the light), the heat accumulated in the steel strip drains through the contact point into the stationary piece of steel more quickly than heat accumulating in the heating coil, so the steel strip cools and returns to its previous position, thereby opening the circuit, and the cycle repeats. Also, I'm guessing the resistance through the heating coil is greater than the resistance through the bulb, so when the circuit is closed, the electricity prefers to flow through the bulb rather than through the heating coil, which also allows the coil to cool down. When both front and rear bulbs are ok, you get a nice slow repetition rate, but if one of the bulbs burns out, the repetition rate increases, because the resistance through the bulb pair increases (the bulbs are connected in parallel, and the resistance through one of the bulbs goes to infinity), so more current continues to flow through the heating coil, so it does not cool as thoroughly as when both bulbs are working, so it breaks electrical contact sooner, so you get more rapid cycling, which alerts you to the fact that one of the signal bulbs is out.
The key is, the current does not flow continually through the heating coil.
The process is like this:
The heating coil is permanently connected to the two outside connectors of the flasher. When the indicator light switch closes the circuit, the current starts to flow on the heater coil, but this is a relatively low current (say 100-200mA), which is not enough for the bulbs to light up. They have a relativeley low resistance (a few ohms), while the heater coil has a higher value (say around 50-150 ohms) to reach the mentioned current. So at first the heater coil starts to heat up, and the bulbs dont do anything. As the temperature of the small steel part is rising, it is expanding in length, and starts to bend the other larger part of the swithching mechanics. When the switching point is reached, the contacts are closed. At this point the heating coil is shorted by the contacts, so there will be no more voltage on the heating coil, and of course no more current either. This is the main reason why the heated part starts to cool down. Because there is no heat supply any more, to override or compensate the heat loss coming from the risen temperature. At the same time, as the contacts are closed, the bulbs are not "powered" through the high resistance of the heating coil, which was not enugh to power them up, but directly through the closed contacts with no resistance, and so the current starts to flow on a higher level according to the resistance of the bulbs. Then in the meantime the smaller steel part is cooling, and contracting, pulling the larger plate back. With decreasing temperature it will reach a point, where the increasing pulling force is enough to turn the larger plate back in the off position. And then the cycle starts all over again.
I've got a 3-prong thermal flasher, and just tried hooking it up to a 12v power supply. Smoke came off the tiny wire! I wondered if I had it wired backwards, so switched my wires around. Again, more smoke, and still no clicking. Any thoughts on what I am doing wrong? I don't seem to have burned anything out yet, but I think I am close. Smoke is never good.
Thank you, I really enjoyed, that!!
Great video sir
Thank you
Please tell me sir what happens if we dont use indicator flasher relay
didn't know how it worked but I do now thanks