Draw schematic for old school power supply

Thread Starter

Circ de Uits

Joined Feb 9, 2016
What started as an effort to restore an outdated (1972) automobile distributor tester, has developed into a desire to understand the electronics of the power supply module. I have photos and a crude sketch of the elements of the module. My goal is to develop a proper schematic drawing of the circuit(s) and understand the function of each of the elements. The main function of the power supply is to drive a rotating plate that contains a flash tube, and to trigger the flash tube for stop action effect. Conductivity through the rotating shaft is by graphite brushes and copper contacts. I would also like to learn which components (if any) may be replaceable with modern equivalents.

Is this a proper topic for this forum? If so, I can scan the sketch for posting and hopefully start a dialog.


Joined Oct 15, 2009
Sure.. post a proper schematic and someone might take the time to walk you through the functions of each sub circuit..

Thread Starter

Circ de Uits

Joined Feb 9, 2016
OK, thank you. I am travelling for a couple of days, but will get the sketch/photos scanned and posted as soon as I can. ( Actually, I wasn't expecting replies so quickly. I am encouraged by the prospect of help on this)



Joined Apr 5, 2008

The shown object looks like an old adjustment tool for contact breakers in a combustion engine.
The flashlight is synchronized with the contact breakers and you will have to adjust the timing.



Joined Jun 22, 2012
Looks like a strobe flasher, with full wave silicon diodes trigger supply, and a valve full wave HT supply, possibly for setting the timing on the distributor on a car engine .


Joined Nov 12, 2008
I may have a schematic after all. I have attached a photo of the module and a PDF of a parts list that I found online some time ago. I must have missed (or forgotten) the diagram when I looked through the document.
I think I just had a flashback. :D
I'm no expert on flash tube, but I give it a shot.
T1 is the power transformer. It supplies voltage for the circuits. Very hard to replace with a single part.
V1 is a rectifier tube. It turns the high voltage AC from the transformer into high voltage DC. Could be replace with solid state.
L1 - filter choke, used to help smooth the voltage and current. Difficult and expensive to replace.
All r's and C's could be replaced with more modern components.
This is the circuit on the right side of Fig. 6. It's purpose is to supply a high voltage to the flash tube, but not so high as to make it flash.
SL1 is a rectifier of an old type to turn the AC from the transformer into DC. It could be replaced
T1 is a pulse transformer to produce a high voltage pulse. Probably hard to replace.
SL2 are also old fashioned diodes I think to clamp the voltage of the pulse transformer. Could be replaced.
The purpose of this circuit on the left of the schematic is to produce a very high voltage pulse to cause the tube to flash.
The timing for the flash comes from another page thru the connectors on the left.