Teardown and troubleshooting: P.G. Electronics PSA300 DC Power Supply Analyzer.

[PA0PBZ]

I already ordered panel meters with 7 segment red LED displays for current and voltmeter just to have vintage look, was a long search because there is way too much LCD panel meters but matching LED meters for both was hard to find.

http://www.baco-army-goods.nl/meetapparaten/led-digitale-paneelmeter.html

[Spawn]

Thanks PA0PBZ

I already ordered one, meter from Baco doesn’t have the right dimensions, the one I ordered fits in the original bezel, I think I forgot to mention the bezel is not attached to the meters, I need to make another bezel and put the new meter in there than I can put the meter from behind in the original bezel but I will also use a smoked Plexiglas to give a better looking finish.

There is no earth connection in the main power cord, I need to earth the chassis so I will change that too.

I got this voltmeter and a matching current meter with a shunt:

[Spawn]

Okay… I didn’t use the load for a while and today I wanted to test one of my PSU’s but the analyzer was fully shorted again, PSU was set on 1A, so I did a quick check and the transistor at same position was blown again. Last time I tested was 8A for a review and nothing more, I don’t understand what’s going wrong I didn’t fix it yet because of an another project I was busy on. Maybe a fast fuse in line with the transistors will help. 

Meanwhile I received the panel meters couple days ago, I need to do some milling to create a flat surface when the meters are in position. Still waiting on smoked foil to mask the display.