[Roadsters] Alternative to Bimetallic Strip Gauge Regulator?

[RWM]

Exactly, Linda.  Depending on the hardware specs, each 1N4001 silicon 
rectifier diode drops the voltage by 0.7-0.8 volts, so for a ~2V drop 
and 7-8V output voltage, 3 in series should work, then measure the 
output voltage to confirm.

I have no idea how, but turns out the OEM VR bimetallic strip and 
heating element had gotten themselves into a twist such that the module 
entered either a constant open or constant closed condition.

I re-profiled the spring and burnished the contacts and the OEM seems to 
work as designed.   I'll keep it as a backup to the solid state module.



On 4/2/2012 2:19 PM, linda wrote:
> Several as in 2? Then you just test the output voltage?
> I had also heard the 510 VR worked but had a different mounting bracket.
>
> Linda
>
> Sent from my iPod
>
> On Apr 2, 2012, at 8:24 AM, RWM<RWM at RWMann.com>  wrote:
>
>> Several 1N4001 silicon rectifier diodes in series as a voltage dropping method makes more sense than a resistor.
>>
>> In addition, a little extra attention to the OEM bi-metallic got it working as designed, so now I have two options.
>>
>>
>> On 4/1/2012 5:40 PM, RWM wrote:
>>> 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