Flash powered light bulb

[DesmondD]

When I first did some high speed flash images with breaking light bulbs a few people suggested they would look better with a glowing filament .



Tonight I opened an older flash , un-soldered one of the capacitor wires going to the tube [ very carefully - about 300 volts involved ] , and soldered a 220 volt light bulb in series with the current that would flow through the flash tube when it fired .
When I had the flash on the low power setting it fired but there was no effect on the light bulb .
However when I put it on full power it had an effect .... too much in fact and I may have to use a flash with decent manual control so I can choose exactly how much energy goes through the filament to get the correct glow .







.

[DesmondD]

I tried another older flash with thyristor control in the hopes that it would switch off sooner for a dimmer glow . The optic sensor would not trigger it this time and then I remembered that it showed "-8 volts" when I measured the trigger voltage . For some strange reason the earth pin is in the centre on this flash - so I had to trigger it manually .
I faced the sensor toward a white surface so it could switch off sooner but I still got what appeared to be a full power 'dump' . That "600 uF" and "330wv" on the capacitor means " do not touch!" in English





.

[BLWNHR]

How exciting. I will look forward to your progress

I will be putting the finishing touches on my audio trigger this weekend after following your helpful advise.

[DesmondD]

How exciting. I will look forward to your progress

I will be putting the finishing touches on my audio trigger this weekend after following your helpful advise.

Show us what you accomplish !

[DesmondD]

Tonight I ran it through a soldering iron as well .
This gives me the glow I need at f16 .






.

[I @ M]

Desmond, I know that I am never going to get around to trying to replicate anywhere near even half of your projects but you are SERIOUSLY great education and entertainment with these posts, don't stop mate.

[DesmondD]

Desmond, I know that I am never going to get around to trying to replicate anywhere near even half of your projects but you are SERIOUSLY great education and entertainment with these posts, don't stop mate.

If I stop suddenly it may be due to this capacitor --- it makes one heck of a noise when I touch the wrong wires together !

[Art Vandelay]

Interesting stuff.

I would not have thought of using a soldering iron as a big resistor. lol

[DesmondD]

Interesting stuff.

I would not have thought of using a soldering iron as a big resistor. lol

I was thinking of putting another 100w light bulb in series , then remembered I had an 80 w soldering iron that wouldn't add any light to the image


.

[DesmondD]

Tonight I tried a few with a white backdrop - I know I need to increase the flash output on the background a bit .








.

[MATT]

Very cool.. There may be an easier way. You can get 12v and 24 v light bulbs. Just hook it up to a car battery..

To many volts to be playing with but cool results

MATT

[birdie]

I love the first one... what you could do, sort of cheating, is add the glow in PP... safer that way too...

Could you just add a potentiometer in series with the blub and then use it to vary the power going through the bulb?

I'm guessing here, but I've got a funny feeling that I've heard that bulbs have a higher voltage/current requirement when cold then when they are hot simply because the higher resistance when the coil is cold compared to when its hot... that could be why its not working with the lower power on the flash...

Also i'm not sure again... but i thought lowering the power of the flash just reduced the length of the flash, so exposing the sensor for a shorter period... could be wrong again though...

[DesmondD]

Very cool.. There may be an easier way. You can get 12v and 24 v light bulbs. Just hook it up to a car battery..
To many volts to be playing with but cool results
MATT

A 12 volt bulb would be so bright that it would be totally white and wouldn't show anything when I break it with a hammer .

I love the first one... what you could do, sort of cheating, is add the glow in PP... safer that way too...

Could you just add a potentiometer in series with the blub and then use it to vary the power going through the bulb?

I'm guessing here, but I've got a funny feeling that I've heard that bulbs have a higher voltage/current requirement when cold then when they are hot simply because the higher resistance when the coil is cold compared to when its hot... that could be why its not working with the lower power on the flash...

Also i'm not sure again... but i thought lowering the power of the flash just reduced the length of the flash, so exposing the sensor for a shorter period... could be wrong again though...

I could use a 'dimmer' switch for a similar effect but with a flash discharging through it I can control the exact amount of energy going through it on each shot , with a dimmer I would have to time when I break the bulb because I may also break the filament which will give me varying results - maybe not too much to worry about though . But using a dimmer would require a drive into town to buy one so being able to do it with what I have available suits me better .
Lowering the power of the flash does reduce the duration , but I'm not lowering its power here , just sharing it between a few consumers at once



.

[MATT]

A 12 volt bulb would be so bright that it would be totally white and wouldn't show anything when I break it with a hammer .
.

I was thinking rather than trigger with flash unit, just hook up a car battery or similar 12v/24v supply. That was all..

MATT

[DesmondD]

I was thinking rather than trigger with flash unit, just hook up a car battery or similar 12v/24v supply. That was all..

MATT

Ok , I did try 12 volts to the bulb and it doesn't light up .
As mentioned though , a constant power supply will still introduce a variable as to how long it glows for before being broken and whether the filament breaks as well - these variables will mean I couldn't control the exact glow of the filament with a continuous power source .

[natogden]

very interesting

[DesmondD]

very interesting

Hopefully this weekend I will get some 'smashing' images