12vdc low amp to 120vac high amp flash/blink lamp inverter circuit?

[Daniel Clark]

I have an aesthetically pleasing old 120v ac 200 watt incandescent slide projector bulb; it looks like a vacuum tube. Picture below. I'd like to have it flash for very brief periods of time at a relatively long interval, something on the order of on for a 1-2 seconds every 1-10 minutes. Doesn't need to be at all exact or regular.

My power source is 12vdc and low amps.

I'm thinking there must be a way using capacitors or something to create a circuit that stores up enough power and then releases it, but I haven't been able to find it yet.

Has anyone seen something like this?

Thanks!

 

[BobK]

200W * 1 second = 200J of energy

The energy in a capacitor is 1/2 CV^2

If V is 120V, C we get

200 = 1/2 C * 120 * 120 = 14400
C = 400 / 14400 = 0.028F = 28000uF

And that is just to have enough energy if you could suck it all out over 1 second. With an efficient boost converter, say 80% you would need 35000uF at say 200V to be safe. That is a hell of a capacitor.

Then there is charging of it. To charge it over 9 seconds you will need 200 / 9 = 22.2W. At 80% efficiency again, say 28W, which is 2.33A. Is that low amps?

Bob

 

[Bluejets]

200 watts out = 200 watts in PLUS losses.

Probably looking at around 20 amps in , so your low power supply simply will not be sufficient.
Well, depending on your view of "low amps".

 

[duke37]

To go from 12V to 120V you will need a substantial invertor. to charge the capacitor and a SCR or fet for a switch.
The life of the bulb could be short since the very high current which is necessary during switch on can fuse the hottest part of the filament. Photofloods are turned on gradually.

Leds would be more realistic to run from 12V.

 

[Daniel Clark]

Have about 1 amp on the DC. So sounds like maybe this is a bad idea if I love life since the capacitor would need to be monumental. Crud. Thanks all!

 

[Audioguru]

I agree that the flashing light bulb will not last long. it might last longer if you keep it warm with some current between flashes.

 

[globecollector]

Keep the lamp for posterity and use LED's. Garaunateed the lamp would be made somewhere like G.E., Bucyrus and the plant long closed....so never replacable.