Homemade voltage regulator for rallye gauges

[Michael789]

Here is a homemade voltage regulator for my rallye gauges,it works perfectly at 4.96 volts.All gauges worked when tested and it cost about 6.00 dollars to make.Nice!!

 

[Chilsam]

Excellent!!!!

 

[aldsed]

Hi, Works great doesn't it . I have don it to several cars and it is imo the best way to go. Great work!!!

 

[D575]

Details please. :confused:

 

[snakeoil24]

Here is a homemade voltage regulator for my rallye gauges,it works perfectly at 4.96 volts.All gauges worked when tested and it cost about 6.00 dollars to make.Nice!!View attachment 141234

Brilliant

 

[Meep-Meep]

I've done that to a couple of cars and it seemed to work well. There is a failure mode that the regulator goes into to but I don't recall the conditions to make it fail. And I don't mean "poof" and it's gone in a cloud of smoke. What I remember is all my gauges going to full sweep after I start the car. Perhaps the initial starting from a slightly discharged battery (car sitting for a week or more), and having the alternator crank up to deal with the initial low voltage, caused the LM317 to go into overvoltage mode.

 

[Gone]

I've done that to a couple of cars and it seemed to work well. There is a failure mode that the regulator goes into to but I don't recall the conditions to make it fail. And I don't mean "poof" and it's gone in a cloud of smoke. What I remember is all my gauges going to full sweep after I start the car. Perhaps the initial starting from a slightly discharged battery (car sitting for a week or more), and having the alternator crank up to deal with the initial low voltage, caused the LM317 to go into overvoltage mode.

Occasionally, but not every time I drive my '70 Bee, my gauges will go to full sweep while I'm driving, then they return to normal. Is this a cause for concern, and if so, what's the fix?

 

[Michael789]

You can get this stuff at radio shack.The regulator is a 7805 c it can handle up to 35 volts input.You have 3 terminals the center is ground, to the left is the input(12 volts)and the one to the right is output (5 volts)this is looking at the vr laying on the table with the terminals facing you ,just like the way you see it on the gauges.You'll also need a heat sinc and a 10 - 100 uF capacitor it has to be at least 15 volts,I used the 100 uF at 35 volts .I hooked the ground terminal to the same location that the old radio filter used to be connected to and then soldered it to the center terminal of the vr(use rosin core).Next take the capacitor negative side and solder to the vr to the same center terminal (you can tell the negative side by the black stripe down the side) then solder the positive side to the input terminal that has 12 volts coming in.This will protect the vr from power surges plus the cap will hold a small voltage charge and bleed off after you shut the car off,that should keep you from getting the full sweep that the Lm317 provides.I'm pretty sure with the Lm317 you have to use a diode and a couple of caps.Next solder another wire(I used 16 gauge)to the input (12 volts)and the output(5 volts)I used the the wire off the radio filter for my 5 volt feed this way all I had to do is just plug it in to the original terminal to feed all the gauges the 5 volts.Then put some artic silver on the back of the vr and screw it together with the heat sinc ,install it in the place where the old regulator was mounted. You can also use heat shrink tubing to help protect your solder connections. It sounds like a lot but it's pretty simple.

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Yes it does, I couldn't see spending 50 bucks for a solid state version of the vr.Thanks

 

[super-bee_ski]

Nice
Thank Mike!

 

[D575]

You can get this stuff at radio shack.The regulator is a 7805 c it can handle up to 35 volts input.You have 3 terminals the center is ground, to the left is the input(12 volts)and the one to the right is output (5 volts)this is looking at the vr laying on the table with the terminals facing you ,just like the way you see it on the gauges.You'll also need a heat sinc and a 10 - 100 uF capacitor it has to be at least 15 volts,I used the 100 uF at 35 volts .I hooked the ground terminal to the same location that the old radio filter used to be connected to and then soldered it to the center terminal of the vr(use rosin core).Next take the capacitor negative side and solder to the vr to the same center terminal (you can tell the negative side by the black stripe down the side) then solder the positive side to the input terminal that has 12 volts coming in.This will protect the vr from power surges plus the cap will hold a small voltage charge and bleed off after you shut the car off,that should keep you from getting the full sweep that the Lm317 provides.I'm pretty sure with the Lm317 you have to use a diode and a couple of caps.Next solder another wire(I used 16 gauge)to the input (12 volts)and the output(5 volts)I used the the wire off the radio filter for my 5 volt feed this way all I had to do is just plug it in to the original terminal to feed all the gauges the 5 volts.Then put some artic silver on the back of the vr and screw it together with the heat sinc ,install it in the place where the old regulator was mounted. You can also use heat shrink tubing to help protect your solder connections. It sounds like a lot but it's pretty simple.

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Yes it does, I couldn't see spending 50 bucks for a solid state version of the vr.Thanks

Thanks, I love stuff like this.

 

[dodge41969]

I did the same to my Coronet about 12 year ago, still on the car and works great. I actually mounted everything in the original voltage limiter case...and mounted the heat sink to the outside of the case as well, (so it plugged in like the original limiter). A friend of mine who told me about this has made these for his Mopars for the last 20 years.