View Single Post
  #9   Report Post  
Posted to sci.electronics.repair
Cydrome Leader Cydrome Leader is offline
external usenet poster
 
Posts: 1,910
Default Vivitar 365 flash unit

klem kedidelhopper wrote:
On Dec 13, 4:19?pm, "William Sommerwerck"
wrote:
There is a pot on the one circuit board. It is not labeled. I turned it
1/8 turn,
fired the flash and let it recharge and the voltage was the same. I will
do
some more checking in that area to see if I can find anything. I wasn't
sure
what the pot would be for.


It might be calibration for the auto flash. Can't hurt to experiment.


Did you measure the voltages on either side of the TO220 device? I'm
thinking that if it were some type of regulator , (with an "in" or
"out") then you might get a clue from seeing what that looks like.
Maybe the pot controls gate current. Lenny


I checked a manual for a 365. it is a "thyristor" model.

Any beefy device on the HV side will be a SCR as I said earlier, and in
series with an inductor. The voltage across it will match that of the
storage cap.