I built a solid state instrument voltage regulator similar to the one
described in Tom's post below. I added a 1K ohm 15 turn trim pot so I
could calibrate the temp and fuel guages (V-out is adjustable from ~7.5
to 8.25V). The regulator works great except I keep blowing the V-output
capacitor. I'm using a 1.0uf (tant. 35V) cap, all other components are
the same except the diodes (adjust to V-out and V-out to V-in) which are
IN4003's because that's all I could find. TIA for the help.
Todd Osborn
San Jose, CA
68 2.0Lx2
>From Tom Walter:
I am working on a solid state replacement but don't have a good unit to
compare with.
Charlie,
There have been a few versions of the solid state regulator made up. I
posted the version below, to which Lou in Australia pointed out a LM7808
(fixed regulator) would have saved me a few resistors. ;-)
Barrie reported his roadster "liked" 7.3 volts, someone else cameback
with 7.6 volts, and my
car seemed to prefer closer to 8.0 volts for a fixed voltage to replace
the mechanically instrument voltage regulator.
Have fun!
Cheers,
Tom
wrote this a while back:
> For the voltage regulator, those electronic hobbyist
> on the list should be able to make a simple replacement.
>
> Parts list:
>
> LM317T (T0-220 package)
> R1 (out to adj pin) 220 Ohm
> R2 (adj to gnd) 1200 Ohm
> Diode (Voltage to in) IN4007
> input cap 0.1ufd (disc 60V is fine)
> output cap 1.0ufd (tant. atleast 16V)
>
> For the circuit, look at a LM317 datasheet. Check the
> LINEAR Databook's (Motorola, National Semiconductor, etc).
> The diode just prevents reverse voltage spikes from damaging
> the regulator.
>
> Mount the heatsink tab with mica washers (pin 2 is connected
> to the tab). Output voltage is apprx 8V.
>
> Note: I think the system, as a whole, was temperature
> compensated. The electronic regulator may cause the gauges
> to read a little higher when it is HOT outside (haven't
> investigated this).
>
> Everything should fit back inside the original case,
> keeping a stock appearance.
>
> For thosee who are NOT electronic hobbyist, it is still
> much simplier to replace the OEM unit with one from
> NISSAN (about $13).
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