High-Performance Flashgun Slave Unit

Last updated 19 December 2005; minor changes 11 July 2006
Stock updated in newsletter, December 2008

pictureSlave units sold by photographic retailers, and designs sometimes seen in the hobbyist electronics magazines, are generally poor in performance. They are not sensitive enough for caving use, and can be accidentally triggered by light from a caplamp beam. My award-winning flashgun slave unit out-performs all 'conventional' slaves. Since 1992 I have sold over 800 kits of parts to cavers throughout the world. You can buy a kit of parts or a partially-built kit (for you to finish off). Alternatively, a ready-built unit, based on an earlier circuit of mine, is available from Firefly Electronics. picture

In 2004 I introduced a new version of the slave unit that is compatible with digital cameras. It can be programmed to count the flash pulses from the camera, and to fire after the appropriate pulse. Kits of parts are now available, and a fully-built version is available from Firefly Electronics

pictureAbove: The standard slave unit. The terminal block for connecting to the flashgun is top left. (Note the cable tie to act as a strain relief in the container). Programming link is top centre. Photodiode is bottom left. Board measures 46 x 23mm (1.8 x 0.9in.) Left: I usually house my units in a small translucent container (it is actually a chemical sample bottle). The tape around the top is sufficient waterproofing, and I use audio-phono plugs to connect to my flashguns. (The Firefly units come with a hot-shoe adapter or a PC synch. lead). Right: The new digital slave unit, in its case.

Further Information

For more information about my slave units, please go to my Newsletter page

Links to other sites

Contact me at david(at)caves...etc.

This page, http://site2.caves.org.uk/flash/index.html was last modified on Tue, 24 Feb 2009 10:30:00 +0000
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