[Roadsters] Alternative to Bimetallic Strip Gauge Regulator?

[RWM]

Verdict:  The Moss solid state gauge regulator works fine, but is a 
little "hot"; I'll be tuning it with a dropping resistor.



On 3/28/2012 8:44 PM, RWM wrote:
> Now that you mention it, Charlie, I recall that.
>
> I'm betting there is ~2V of additional voltage drop in a 40-year old 
> electrical harness and connectors...
>
> - Bob
>
>
> On 3/28/2012 7:26 PM, Ken.Smart at csiro.au wrote:
>> For reference.
>>
>> Those with long memories may recall Tom Walter's solid state voltage
>> regulator. I built one many years ago based on his specs.
>>
>> A quick read of the Moss Motors PDF indicates that it drops the 
>> voltage to 10v
>> (unless I missed something )
>>
>> Toms original post is copied below from the list archive indicates 
>> the need
>> for a voltage lower than 10 somewhere around 7-8v:
>>
>> > 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).
>>
>>
>>
>>
>> -----Original Message-----
>> From: datsun-roadsters-bounces at autox.team.net
>> [mailto:datsun-roadsters-bounces at autox.team.net] On Behalf Of Roy 
>> Haslett
>> Sent: Thursday, 29 March 2012 7:14 AM
>> To: Walter.Peterson; 'RWM'; 'Datsun Roadster List'
>> Subject: Re: [Roadsters] Alternative to Bimetallic Strip Gauge 
>> Regulator?
>>
>>       Thanks for the great info everyone, my fuel and temp gauges 
>> have been
>> indicating a little low.  This part should do the trick.
>> Roy
>> 67 low 1600