Author Topic: photoflash cap charger  (Read 1201 times)

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Offline LaserTazerPhaserTopic starter

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photoflash cap charger
« on: March 19, 2019, 06:06:31 am »
looking for resilient, robust, high speed(charge under ~3seconds) electrolytic photoflash cap charging circuit 350-400v 300uF-800uF.
preferably something which triggers a switch device after cap reaches a preset voltage.
anybody seen any?
« Last Edit: March 19, 2019, 06:30:42 am by LaserTazerPhaser »
 

Offline LaserTazerPhaserTopic starter

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Re: photoflash cap charger
« Reply #1 on: March 19, 2019, 08:48:56 am »
What kind of safety level are you looking into? If you don't give a shit to safety, a voltage doubler on mains with a current limiting resistor sounds like a great idea.

I was looking for small dc step up to cap voltage as in lipo powered.

The voltage multiplier is least components to implement Im just not sure which form of capacitors are well suited for mains capacitve coupling.
« Last Edit: March 19, 2019, 10:22:26 pm by LaserTazerPhaser »
 

Offline soldar

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Re: photoflash cap charger
« Reply #2 on: March 19, 2019, 09:15:34 am »
What kind of safety level are you looking into? If you don't give a shit to safety, a voltage doubler on mains with a current limiting resistor sounds like a great idea.

In Spain (at 230 V mains) no doubler needed.  Many years ago I had a long, thin extension cord to my flash and was taking some photos in my apartment and went out to the terrace which had plain aluminum doors. My girlfriend (who was naked and the object of the session), as she stepped out did not realize the cable was there and closed one side and the door pinched the cord and sparks flew and the breaker tripped and she was startled and luckily she did not get an electric shock which she well could have. Some decades ago we were not so safety conscious. I remember a guy saying "protective earth is for sissies and a waste of money".

Charging a flash capacitor from batteries requires a switching converter which would need to be of minimal volume and weight. My old flash just kept the oscillator going after it was charged and had a very simple system with a voltage divider and neon lamp to show when it was charged. The main problem is winding a tiny transformer but maybe you can find an old flash. I have a box full of old flash units which I have no idea why I am keeping them except that maybe one day I will play with them. The charging circuits inside are tiny and I doubt I could do it better.
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