Still looking for a Tripp Lite PR-25 (or similar) DC power supply schematic

[Paul P]

Still looking for a Tripp Lite PR-25 (or similar model) DC power supply
schematic to repair the club's repeater power supply. If any one has one
I'd appreciate a copy, email or otherwise.

I called Tripp Lite just now. According to Technical Support their
PRESIDENT has
recently mandated that they would NOT send any more schematics out.
However, I could trade the supply in for a new one at about 85 bucks.

Thanks and merry Christmas,
Paul.

paul at ppinyot dot com



>>> Looking for a Tripp Lite PR-25 dc supply schematic
>>
>> Have you called 'em at:
>> (773) 869-1111
>> I blew up one of my many Tripp Lite sine wave inverters and they sent me
>> the schematic, free!...
>>
>
>

[gb]

"Paul P" > wrote in
message ...
>
> Still looking for a Tripp Lite PR-25 (or similar model) DC power supply
> schematic to repair the club's repeater power supply. If any one has one
> I'd appreciate a copy, email or otherwise.
>
> I called Tripp Lite just now. According to Technical Support their
> PRESIDENT has recently mandated that they would NOT send any more
> schematics out.
> However, I could trade the supply in for a new one at about 85 bucks.
>
> Thanks and merry Christmas,
> Paul.
>
> paul at ppinyot dot com
>

Paul -

IF it uses the standard LM723 IC regulator and pass transistors (2N3055,
2N3771, or 2N3772) you do not need a schematic per say - to repair. Check
the pass transistors with you trusty VOM/DVM .. can replace 723 !!

Here is the DIY web site for linear supplies
http://www.kbt-dc-supplies.com/index.php

Astron schematics (everyone else copies them)
http://www.repeater-builder.com/astron/astron-index.html

Regulated Power Supply construction (how a linear supply works)
http://www.seits.org/features/pwrsup.htm

w9gb

[PS_DUDE]

hi paul,

Tripp lite makes good supplies but lacks in the
support side !

Good thing is the supplies use off the shelf parts
or easy substituted parts from anywhre,
http://www.mouser.com etc.

What problem(s) are you having ?

73 ps dude

[Paul P]

There are a couple of smoked resistors on the regulator board. I can not
trust the ohm meter reading so I wanted to verify its value. I am trying to
avoid De-engineering the board. Now once the resistors are replace there
may be something else that smoked the resistors too.

Paul.

"PS_DUDE" > wrote in message
...
> hi paul,
>
> Tripp lite makes good supplies but lacks in the
> support side !
>
> Good thing is the supplies use off the shelf parts
> or easy substituted parts from anywhre,
> http://www.mouser.com etc.
>
> What problem(s) are you having ?
>
> 73 ps dude
>

[gb]

"Paul P" > wrote in
message ...
> There are a couple of smoked resistors on the regulator board. I can not
> trust the ohm meter reading so I wanted to verify its value. I am trying
> to avoid De-engineering the board. Now once the resistors are replace
> there may be something else that smoked the resistors too.
>
> Paul.
>

Paul -

Where are these resistors .. the typical linear supply has low ohm
equalizing resistors across the NPN pass transistors .. and only a few in
the regulation circuit off the LM723 pins .. for example a 1 K is usually
used from pin 4 to the voltage adjustment potentiometer.

gb

[ehsjr]

Paul P wrote:
> There are a couple of smoked resistors on the regulator board. I can not
> trust the ohm meter reading so I wanted to verify its value. I am trying to
> avoid De-engineering the board. Now once the resistors are replace there
> may be something else that smoked the resistors too.
>
> Paul.
>

Here's a link to an Astron supply:
http://www.seits.org/features/pwrsup.htm

Assuming a typical 723 ==> pass transistors linear supply,
it shouldn't be hard to figure out the values of the cooked
resistors. The schematic at the link above serves well as a
model for many (most?) of that type of supply. Combined
with the LM723 datasheet, you can fix it.

Ed




> "PS_DUDE" > wrote in message
> ...
>
>>hi paul,
>>
>>Tripp lite makes good supplies but lacks in the
>>support side !
>>
>>Good thing is the supplies use off the shelf parts
>>or easy substituted parts from anywhre,
>>http://www.mouser.com etc.
>>
>>What problem(s) are you having ?
>>
>>73 ps dude
>>
>
>
>