Re: Solid state voltage regulators

[jlandry@domain.elided (John A. Landry)]

jmbrodsky@domain.elided scribbled in the sand:

>     I think it was John L, but, I'm not sure who came up with a setup 
>     for making a regulator, for 5v for the Fuel guage.  Questions:
>     1) I thought it used a 7805.  Why did you choose that over another 
>     part, and what case configuration did you get?

The FAQ entry at http://www.binderbulletin.com/faq/5.htm#12 will answer most
of your questions.  After you read it, feel free to holler if you have more
questions.

>     2) the output on the 7805 is limited to 1A.  Is that sufficient for 
>     the guage, and will it be in service years from now?

See the FAQ mentioned above.

>     3) does the response on the guage read full when full, empty when 
>     empty with this change alone, or is there another step?

Depends on many different factors.  Assuming your CV regulator is the only
problem and it's putting out too little voltage, then replacing it should cure
the problem.  If however your gauges are at fault or the sending units (most
likely) are causing problems, then replacing the CV regulator will have little
effect.

>     4) does it speed up the response of the guage, as I have dual tanks 
>     and want a faster reading, when switching, currently it takes a few 
>     minutes to stabilize.

Not much unfortunately.  20+ year old heated coil bi-metal gauges are just
plain slow and tired.  If you're after accurate fast reading gauges, your
going to have to go aftermarket... Autometer, SW, VDO, Cyberdyne, etc.

>        I'm planning on making a few different voltage regulators, and 
>     some as much as 10A.  I'd just like to know about the fuel guage 
>     now.

To the best of my knowledge, the stock IH fuel tank sending unit is supposed
to comply with the Chrysler resistance standard.  My testing seems to near
this out.  That would be 78 to 10 Ohms.  78 Ohms when empty and 10 Ohms when
full.

Good luck,

John
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