I have hunted through the internet with my good friend Google, but have had no luck finding what I want.

Can anybody help with a schematic (WITH transformer winding details if possible) of a studio type flash/strobe unit.

I am a keen photographer who has always wanted a small studio setup, but can't afford the very expensive (in this country - South Africa) studio units.
Thanks

 

How could you have looked on google for flash/strobe and not have found anything? Doing a google search for "Strobe flash circuit" provides over a half million hits. The first one being
http://members.misty.com/don/donflash.html
which seems to contain all the information you're looking for.

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Thanks for the VERY fast response.

When I said I had Googled - perhaps I should have said that I found nothing suitable. The site you pointed out is one I have looked at, but doesn't have the sort of info I am looking for.

I need a professional-type unit, with adjustable settings (either as power output steps, or f-stops). None of the sites I looked at have something like this, which is why I came to this board.

Thanks anyway, for replying.

 

Do you understand how the circuits you found work?

If not then perhaps you read the descriptions and figure them out, then you'll hopefully have enough experience to design your own. The chances are you can use exactly the same transformer, along with the oscillator plus additional components (possibly a micro-controller) to give the features you require.

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It is not difficult to modify the circuits provided to produce variable output, you just change the voltage the capacitor charges to, and/or modify the capacitor value itself, perhaps having a dial switch which changes capacitors and a simple pot hooked up to a high voltage comparator to change the voltage. The success in building a professional quality device is going to be directly related to your electronics experience, one way or another you'll pay for the unit, either in the time you spend learning to understand and build it or in cash to buy a professional unit. Aside from that, all you need is a diffusion screen. I'm not a professional photographer but I know the basics and I've used simple copy paper as a diffuser to increase the quality of some photo's. Even a white sheet would work. Building it to look good and function properly is up to you.

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I second that.

May I also add that even if it costs you the same or even slight more than a professional unit in parts, the knowledge gained in building it is well worth the extra time spent.

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Screen name: Aloone_Jonez
And http://www.silicontronics.com, same screen name as here.

 

With things like hi-fi audio equipment and photography flashers / light meters you can save a huge bundle building it yourself, though calibration is an issue. Nice thing about photography is you can use the pictures themselves to do the calibration, in audio if you have a good ear you can use that, or any cheap o'scope and some basical function generators can allow you calibration they don't even do on the high end units.

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Thanks for all the replies.
I have a reasonable understanding of electronics - mainly in the audio and test equipment fields.

I think I want the whole flash design "handed to me on a plate" is that I am VERY cautious about working with such high voltages, have little experience in voltage doublers etc.

Ideally, for a studio set-up, the strobe heads would be line powered, which scares me even more!!!

I have gone back and looked at some of the schematics on the link given and have downloaded the relevant descriptions to see if I can summon enough courge to have a go!

Thanks again.

 

You may find some useful info at Sam's Strobe FAQ
The site is geared around repairs and includes circuits of commercial units from which may get some ideas for your own design.

Simple units may be fine as fill ins but for a main unit it's nice to have a light sensor* which can detect the light from the flash and turn off the tube when enough light has been received

*Some units have a sensor extension lead which allows the flash unit to be positioned remote from the camera.

 

Line voltages shouldn't scare you, though you should respect them. If you use a transformer properly rated for the current you're going to need it's very safe. Mains power is great for flash circuits because fully rectified AC mains (120 volts) will give you peak to peak voltages of 370volts (less circuit losses and local variations) perfect for flashes, and easy to double. I'd recommend using a simulator like LTspice to play around with a few basic circuits and using it's probe features to look at the voltages developed at various points. Once you know what is going on using a simulator building a real circuit is much easier. I have first hand experiance with brushes against 80u caps charged to 300 volts, you see stars just like in the cartoons =O mind you that was powered from a 1.5 volt battery... Just don't supply a circuit path across your chest cavity or wrap your hand around something carrying high voltage potentials and you're fine.

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I would say don't do it. Buy a used one. These components aren't cheap or readily available outside heavily developed nations. And it's hardly just the electronics- the strobe reflector etc is a bunch of separate issues. Also for good photography there's some subtleties in tube type, voltage, resistance, inductance to get the right color and pulse width.

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I thought what I'd do was I'd pretend I was one of those deaf-mutes.

 

Use an isolation transofmer for mains testing and keep one arm behand your back, that way you shouldn't recieve lethal a shock even if you do touch the circuit.

__________________
I also post at the following sites:
http://www.stop-microsoft.org http://www.heated-debates.com
Screen name: Aloone_Jonez
And http://www.silicontronics.com, same screen name as here.

 

First - thanks to all who reponded.

Second - Oznog - Excellent suggestion, but this sort of thing is not easy to find on the second-hand market here, and besides, despite my caution, I really want to try and build this thing myself.

The hardware aspects can, with a bit of ingenuity, be solved. Not, perhaps to high-class professional standards, but certainly good enough for my home studio.

I have cobbled together a circuit, using sections from a couple of posted designs, and included a switched-level incandescent lamp dimmer so that I can use modelling lights before triggering the flash.

I'll post the schematic before attempting constuction and would be grateful for any comments.

One lat question: When the flash is triggered, are the modelling lights switched off? I would imagine not, as the light level from the flash will certainly over-ride the incanscents, but will the incandescents cause a colour temperature shift, or give a slight red cast to the exposure?

 

The flash is so massively bright it completely overrides any existing light.

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PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

OK, with much research and a lot of help from a diverse group of extremely helpful people, here's my design.

I don't want to commit it to construction until I am sure all is OK, although I have begun the process of designing printed circuit boards.

I have incorporated Rolf Randby's slave trigger on the understanding that it be used solely for private use.

All comments and criticism, good or bad, will be really appreciated.

Thanks for the help and suggestions to all who contributed to this thread.

Attached Files

Studio_Flash_Schema.pdf (150.7 KB, 7 views)