DSLR Modding help -Flash discharge

[Ibbo!]

I did my 1000D without any problems, I think I have stuffed my 40D as I was replacing the shutter.

Just how do you discharge the flash capacitor safely before you start the job?

Thinks in advance

Steve

[Psychobilly]

Using a Good old analog multimeter on 50 or 100V DC range....it safer than usign a resistor as you will have insulated probes and can se the voltage falling away as the cap discharges it can still take a while depending on the meter...

A DVM has too high an input impeadance to discharge the cap ...

Peter...

[Ibbo!]

thanks peter

now to find the old voltmeter if I can

Steve

[simonmc]

Look in pound shops and the like. The one local to my old place in wilts always had cheap analogue meters in. There about 20,000 ohms per volt. As Ibbo! says you should see the voltage drop as the cap discharges. You really dont want it to discharge though your self!

If you CANT get one and you have a DVM, pull the leads out and put a 20K resistor across the banana plug ends, then discharge the cap by putting the probes on each electrode of the capacitor, keeping yourself well away from the banana plug end. I cannot stress how careful you have to be. When i did my apprenticeship in the MOD i was given a very good demonstration of what a small electrolitic cap will do if miss handled when charged. They can go off better than a detonator for certain types of explosive. To be fair it was well over charged, and we had a surpless of explosives... All good fun to keep the MOD plod on there toes..

Simon

[Islander]

Remember that high value capacitors will recover a portion of their charge after an apparent discharge (I've seen people caught out by this - the worst were from CRT final anodes that sit at around 1kv per diagonal inch) Leave the meter or resistor connected for a minute or so to be certain of a full discharge.