Xenon flash lamp with insufficient tube voltage...but uses doubler circuit.....ok?

[treez]

Hello,

We have 2W xenon flash lamps which run off 12V.

They simply use a switch mode charger circuit to charge up the tube cap and then flash the tube.


The minimum tube flash voltage is 170V, but we have a supply that only goes up to 150V.

Supposing we use the following trigger circuit which doubles the tube voltage for a few hundred nanoseconds at trigger time.........


https://i50.tinypic.com/nco3s9.jpg

...well then, will this mean that we can get away with our 150V supply?

 

[FvM]

I would try with a suitable step-up converter first.

 

[jiripolivka]

Typical flash lamps need >170 V to operate. Fortunately, the operation is based on discharging a capacitor; the discharge duration is short, some 20-50 ms while to charge the capacitor, the power supply has a longer time.
My advice is to find a DC-DC converter capable to charge the capacitor to >180...200V. If you can modify the existing circuit, use a voltage multiplier with diodes and capacitors to get more voltage. Maybe the original circuit has a bad diode or capacitor. Also test the charging capacitor, some can leak and overload the power supply. Be very careful, a charged capacitor is dangerous at 10-100 uF, ~200 V. Also the DC-DC converter is dangerous due to high voltages in it.
The triggering circuit develops up to 5 kV pulse, also dangerous to touch!

- - - Updated - - -

What is the AC input voltage, V1? If it is 120 V AC, then the full voltage in "141" capacitor will be ~150 V. If you use a voltage doubler, you can get up to ~300 V DC. Then the capacitor may fail- check if it can hold 300 V.

 

[treez]

Thanks, our xenon flash tubes only conduct for literally 200us.........every 800ms............its amazing that such a short time burst can be seen ....and it looks like its on for a few 100 ms.

 

[BradtheRad]

I once made my own car engine timing light, using a xenon strobe lamp from Radio Shack.

Powered by 120 VAC mains through a voltage doubler. The capacitors were 4uF @ 600V.

Triggered by a single wire held against the #1 spark plug wire insulation. A clothespin was sufficient to maintain pressure.

The voltage doubler produced between 300 and 340 V at the bulb. This was adequate according to the instructions.

It worked fine, although I suspect the bulb sometimes skipped a flash because the capacitors needed to charge afterward for an extra cycle.