Now you're all in trouble...

After a recent strobist shoot it quickly became obvious that my single SB800 wasn't going to be enough, and although I was able to borrow some more from a good friend, I really needed a more permanent solution.

 

Not having the money to blow on 3 more SB900/800 or 600 flashes (that's posh lens money that is!) I thought I'd see what I can do with a soldering iron. Unfortunately soldering irons only emit heat and not light so I turned to ebay.

 

5 days later I'm the proud owner of some classic strobes. Two Vivitar 283s, a Vivitar 285 and some great little micro controllers from a friendly Dutchman.

 

The 283s had 300volts at their hotshoe, so they weren't going anywhere near my D300! The 285 was only 7 volts, but it's all going off camera anyway.

 

I have the prototype hardware sorted, now I just have to program the microcontrollers

 

What you can see here is

Vivitar 283 - £16 from ebay

6v 7.2Ah SLA battery - £14 from Maplin

JeeNode(V4) - €17.50

2xOptotriac isolators - £1.50 each from maplin, far cheaper from Farnell (but still cheaper than getting 300v up the Jeenode!)

 

The Jeenode(V4) comes complete with an RFM12B radio module, meaning I have all the parts needed to make a remote trigger. The hotshoe even unscrews from the vivitar flashes, which means I've even got a useful donor part to use for the input to the transmitter.

 

Button board and breadboard are for test purposes only. Triple AA battery box will only be used on the camera trigger transmitter end, not the remote strobe end. The remote end will run from the 6V SLA

 

Due to the low internal resistance of the 6 volt sealed lead acid battery the 283 recharges from a full blast in under 3 seconds! Probably best not to do too many of these in quick succession or the oscillator circuit is bound to melt. I'd add "improve flash cooling" to the "to-do" list.

 

Bar the external battery connection wires the 283 is unmodified. Everything that is required appears on the connector behind the thyristor sensor. A bit of veroboard and some 0.1" spaced circuit board pins make a good plug.

 

For anyone that's interested the pins are

1.......2

....3

4.......5

 

(This is my numbering system looking at the front of the flash from the outside).

1 - Connects to the internal triggering system, this sits at 300volts

2 - Quench1

3 - The other half of the trigger. This connects to the outside of the hotshoe. Connect this to pin 1 and the flash will fire

4 - Connection to hotshoe centre. With the Thyristor unplugged the hotshoe is disabled. Connect this to pin 1 to reenable it. I left it disconnected, I don't want 300volts on the hotshoe centre pin!

5 - Quench2

 

Connecting Quench1 and Quench2 together stop the flash instantly.

Connecting different resistances between it varies the power.

I'm using the connect directly together method via the microcontroller to quench the flash after a preset time. The longer the time, the higher the flash power.

 

Oh, and for anyone interested, this picture was taken with the SB800 on hotshoe pointed straight up, camera was tilted at 45 degrees so the flash bounced off the white ceiling and the white tiles on the wall... The white surface it's all sitting on is the top of my chest freezer in the utility room!

 

Progress is made, and flashes flash... www.flickr.com/photos/steve_snaps/4566541603/

Done