Hi,
no a electronic pro, so far I've created a small flash clapper circuit using micrphone and LED nothing fantasy yet.
But I want to use disposable camera flash unit instead of using LED, how I can approach this ? I need expert advice please.
Thanks
Jake
Well I guess the first thing you might do is test the trigger voltage on the flash, as it is likely to be around 150v, and some isolation circuit would be in order before it gets near an Arduino. You would also be well-advised to treat the entire flash assembly with caution. It may be encapsulated.
Nick_Pyner:
Well I guess the first thing you might do is test the trigger voltage on the flash, as it is likely to be around 150v, and some isolation circuit would be in order before it gets near an Arduino. You would also be well-advised to treat the entire flash assembly with caution. It may be encapsulated.
Thanks,
So basically I was thinking to take out the flash unit.
Find these 2 copper contacts that triggers the flash
solider wires then connect to arduino output.
is this gonna work or break the arduino ? i'm really electronic newbie 
is this gonna work or break the arduino ?
The latter.
Use a relay if in doubt, and don't forget to turn off the power and short the contacts before you do anything to them
Use a relay.
Most of these units charge the hv NEGATIVE with respect to the battery terminals,
The camera will have a pair of mechanical contacts on the shutter, connect the relay to those.
thanks - never have used a relay before does it matter which / what type of a relay switch ?
would Optoisolator work? https://www.sparkfun.com/products/314
How about if I make the flash unit slave and separate circuit first, then integrate with the arduino ?
If the trigger voltage is relatively high, use a MOC3020 opto-triac.
please have a look at this circuit : http://www.instructables.com/id/Arduino-Camera-Flash-Control/
would it be possible to the same thing with disposable flash units?
Yes, and a relay is a bad idea.
You should short the trigger wires several times with the battery disconnected. If you can see the charging capacitor, you should short that with a resistor held by pliers to completely discharge it.
jasperfly:
please have a look at this circuit : http://www.instructables.com/id/Arduino-Camera-Flash-Control/would it be possible to the same thing with disposable flash units?
It is possible, usual method i see is to use an scr to trigger the trigger transformer but you need the circuit diagram to connect it correctly.
Scr should be as close to the trigger transformer as possible.long wires can cause the cheap cameras not to fire.
Feed the scr via an opto isolator.
Keep the supplies and grounds totally seperate between the arduino and flash.you need to power the flash from batteries only.
Fwiw, a few of my pyro mates have done this for firework controllers.
Iv seen a fair few complaints of fried arduinos.
As mentioned you need to be careful if you open up the electronics, they have a very nasty bite.
Hi guys,
So I got the flash out and have attached a picture, how can I possibly trigger this using arduino ? :~
question : do I need to have battery for the flash in or i can use arduino 9v source?
A TIP120 isn't a FET, is it?
What voltage did you measure on the flash contacts?
Is it safe to apply that voltage to your transistor (wherever it turns out to be)?
Use a battery for the flash.
When the flash fires a short high current pulse is generated.
Any common connection to the unit could destroy the arduino.
I suspect induced voltages but dont know except pyro mates experience.
As said previously they have experienced several fried chips.
AWOL:
A TIP120 isn't a FET, is it?
What voltage did you measure on the flash contacts?
Is it safe to apply that voltage to your transistor (wherever it turns out to be)?
Assume 200 V across the contacts.
You will NOT be able to measure this with a dmm.
An electrometer is required.
AWOL:
A TIP120 isn't a FET, is it?
What voltage did you measure on the flash contacts?
Is it safe to apply that voltage to your transistor (wherever it turns out to be)?
Thanks, yes to all 3 questions.
could you please assist me further ? I'm stuck.
Tip 120 is a darlington not a fet.
Max voltage is 100 v which is not enough.
Use an scr or a fet with a seperate protection diode.
You may measure i guess 50 to 60 v assuming a 10 megohm dmm.
The actual voltage will be 150 to 200.
To get the correct voltage you need to know the circuit and apply kirchoffs law.
If you identift the camera you are using get the circuit off the internet and post a link, then i will try to show you how.
Many have played with these and most have been reverse engineered.
A relay would be much simpler though.
