[TechAssist] Re: Home made variable DC Power Supply
- From: Gary McCartney <gary@xxxxxxxxxxx>
- To: techassist@xxxxxxxxxxxxx
- Date: Fri, 01 Aug 2003 01:55:17 -0400
Warren, that 8 pin IC was probably an op-amp such as an LM301, LM741 or
similar.
I have plans for a nice and easy regulated power supply, variable from
1.2V up to approx. 35V and at 5 amps. I'll either find the schematic or
draw it up for you. It involves an LM338 3 pin variable regulator. A
cheaper LM317T could also be used with the TO-3 transistor set up as a
bypass to provide the heavier amperage required. If zero volts output is
required, then the regulator would have to be somehow referenced to
-1.2V to bring the output down to zero.
I have plans too, for a 0V to 35V supply but it involves more parts.
This one has variable current limiting adjustment as well.
Gary McCartney
McCartney Electronics
7134 Fife Rd, RR 7
Guelph Ontario Canada N1H 6J4
Fax: (519)821-1530
email: gary (at) number63.ca
"Warren C." wrote:
>
> Hi All
>
> My old DC PS finally Quit regulating, problem is it was built so many
> years ago
> that I no longer have the schem.
> It controls the Voltage output from 35 V down to about 1.5V
> The current can be adjusted from 2A down to about 5ma.
>
> I've found some bad caps and replaced them but it still does not
> regulate down below
> 10 V and it used to.
> The main problem (I think) is the reg. IC# is IC321 and I can't find it
> or cross it.
> It is a 5/16" can type with 8 legs on it. The IC controls a large heat
> sinked T O 3 trans.
>
> Does anyone have info on this IC??
> I would welcome your schematics for similar home made PS's
>
> Secondly where in Canada can I buy a ESR cap tester. No insult but I
> had a bad experience
> years ago with an electronics company in the States. I sent down a mail
> order for about $350.00
> It was cashed but never received any thing for it and no replies
> afterwards..!
>
> TIA
>
> Warren Campbell
> Campbell's TV & Appliances
> Cannington On
> Canada
>
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--
Gary McCartney
McCartney Electronics
7134 Fife Rd, RR 7
Guelph Ontario Canada N1H 6J4
Fax: (519)821-1530
email: gary (at) number63.ca
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