Pulse Pendulum Projects

[picowatt]

I'm not a huge fan of elektrotanya although they do have some manuals you can't get elsewhere. They have adware and try to get you to download a reader etc.

But the 40 page AC power supply manual is also available from the TekWIKI site, which is a great resource for all the older Tektronix scopes:

http://w140.com/tek_422_ac_powersupply.pdf

Other manuals too, for later serialnumbers, etc:

http://w140.com/tekwiki/wiki/422

TK,

Good to know.

I was having a bit of trouble finding the supply schematic and just grabbed the first one that came up.

Thanks for the links.

Those hand taped layouts and gold plated boards are a works of art...

PW

[thngr]

one must learn current does not run coil at onece.(this topic all about it) but in small motors neo magnets used to upgrade their efficiency not to overunity.

[PhiChaser]

Thanks for the replies and the links guys.
I might have time tonight to delve back into it.
I agree with both of you, these boards are works of art.
It is an AC supply, not one of those harder to find AC/DC or straight DC ones.
I don't have a variac, I only have a (cheap) 5A30V DC bench supply (I haven't even had much of a chance to break it in either).
Any idea on this Christmas light?
(second picture is without power on)

Thanks again,
PC

[PhiChaser]

Nevermind, that is an electron tube and those are supposed to glow (I guess?)...
The search goes on... I need to start tracing wires, I was hoping it wouldn't come to un-soldering things.

PC

[TinselKoala]

Yes, that's a neon, it's supposed to glow, they are used in voltage regulator circuits a lot. The fact that it is blackened generally means it has been working hard, but this is probably normal. But check that the line fuse to the AC supply is the correct value. If the unit blew fuses at some point and someone replaced it with a larger value, that's not good.

It sounded like you have one of the power supply voltages out of tolerance. This should be checked first. The problem may be on the supply side, like a bad capacitor, or it may be something in the circuit it's powering that is drawing too much current and pulling the supply voltage down.

It looks like a lot of the board connecting wires are on socket-pins, they can be pulled without unsoldering. Just note where they go! Take pictures!

When you start in with the soldering iron, I would check the output side of the HV transformer first. Unsolder all the wires on the output that feed to the CW bank and the CRT filament, tape them up so they can't short against anything, Or maybe, find the other ends of the wires, they could be plugins to the respective boards, that would be nice. Then check the transformer for output. If you don't see any, it could be that the transformer is bad (  ) or that the multivibrator on the input side isn't multivibrating. It's a good idea, I've found, to take pictures as you go, and label wires so that you can get them back where they belong.

A variac is a good investment if you are building an electronics workbench, they are handy for all kinds of things.