Asking publicly so that others can benefit from the answer here

How do you go about making a adjustable voltage limiter for your instrument cluster? I'm thinking I may as well go solid state on my cluster while I'm acquiring all my aftermarket gauges...

_________________
'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

You don't need a voltage limiter when using after market gauges.

I know. I just want it for my stock gauges since it'll probably be a little while for me to get all the aftermarket ones.

_________________
'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

LM317 is a very popular part for this sort of application. Place a 240 ohm resistor between Pin 1 and pin 2, and R from Pin 2 to ground. Vout would be 1.2V + R*0.005, and taken from Pin 2. Ie, for 5V, make R equal to about 750 ohms. You can use a trimpot here, a 2k pot would probably work best, that'd get you 1.2V to about 12V.

I'd use 10uF capacitors on input and output; 25V electrolytics would probably be just fine. More is better on the Vin pin (Pin 3). Just be careful: the tab is tied to Vout. Do not ground the tab!

You can also do the old trick of putting diodes into the ground lead of the 7805 series of regulators. Each diode will boost the output by 0.5 to 0.7V, depending upon what diode is used (0.7 for 1N4001/related and 1N4148/1N916). You could put 1N4001/related on the output to drop voltage too. Just be careful with the diodes on the ground lead (pin 2) though: the tab is tied to pin 2 also, and you'll defeat the diodes if the heatsink is grounded also.

I know a little bit about electronics, but yer still speaking Greek to me for the most part. Now my brain hurts

_________________
'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

Sorry, it's my background...

i'd pay someone to do it so I don't have to re-read that... LOL...

_________________
65 Coronet, 4 bbl, .060 over, mild cam.
66 Valiant, Black, 3spd, Hyperpak, headers.
works in progress...

It made me cross-eyed.

On the upside, now I have TWO Dusters!

waitaminute...

_________________
'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

I understood it


(and I'm not in the field)

_________________
Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Ya may not be in the field, but you're obviously still over my head with understanding electronics

_________________
'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me