Bench Power Supply?

[misterc57]

After countless years my bench PS (Sencore AC Powerite) meter needle has failed, making the unit useless. Below is a pic of the unit in the OFF state, the needle should all the way "left" at zero.

Looking for recommendations where I can dial up AC and monitor AC and Current. Maybe a dual display.

Watching a needle movement has become second nature to me but I wonder if a digital readout would make sense to quickly detect bad high current situations.

Thank you.

[The Dude]

I would carefully take the meter apart and see if it can be repaired. Often times it's just a static charge and a good cleaning will make it work. Sometimes it's a stuck/mechanical issue and a cleaning and slight bit of lube will make it work again.

[Tom Phillips]

If you are interested in taking a shot at fixing it, I have seen newsgroup discussions in which people fixed analog meter movements. Many found a small bit of debris that was interfering with the needle movement.
Have you tried twiddling the zero setting adjustment screw to determine if that mechanism is snagging the needle?

[drewl]

aside from those great mechanical suggestions, it might be something simple in the needle driver circuit.

[tedmich]

https://pacifictv.ca/schematics/sencorepr57data.pdf

its super simple!

As to using a fancy digital meter here is a discussion on the issues : https://www.eevblog.com/forum/beginn...er-for-variac/

[misterc57]

Something odd is going on. Today the needle has reseated itself back to normal.

Past couple of days it was resting below zero and I would have to tap on the panel and it would reset to zero. Also a few times yesterday it had pegged a few times when it should not, and then it was in complete failure mode.

Today it is acting normal.

[Tom Phillips]

Something odd is going on. Today the needle has reseated itself back to normal.

The symptoms could indicate that there is a bit of something in the meter movement that cause the needle mechanism to jam. It's possible that it will never happen again so it could be a good idea to just keep using the instrument for now and maybe it will never happen again. That Sencore is a nice instrument and is much more advanced than just using a variable transformer with a voltage/Current meter.

[mozz]

The old saying, when trying to fix a meter movement, it's not working, once you get done, it's never going to work now. Unless you are a jeweler, good luck.

[misterc57]

The old saying, when trying to fix a meter movement, it's not working, once you get done, it's never going to work now. Unless you are a jeweler, good luck.

The couple of times I have tried to do anything to a meter needle were a disaster.