updated 05/28/2008

Addressing an issue with Canon flash units

Customers have reported that when using the delay unit outputs to trigger Canon 430ex and 580ex flash units, the flash unit is disabled after each discharge until either the flash unit or trigger circuit is manually reset. In order to correct this problem, we are now including two 1-kW replacement resistors with each delay unit and combination kit. These resistors would be used in place of the 22-kW resistors that lead from outputs 5 and 9 of the 556 timer.

Recent additions

...a crossed-beam photogate kit. This is an add-on for either a TPG or SPG photogate. With the addition of a phototransistor-LED pair and a bit of wiring, one has a photogate that can be used to automatically discharge a flash unit or actuate a camera shutterwhen an object passes through the intersection of the two beams.  This makes it useful for photographing objects moving toward or away from a stationary camera.

...a new trigger kit...the light-activated trigger. This trigger operates the reverse of our photogate kits. The output of the light-activated trigger is switched on when light shines on the detector. A laser pointer works particularly well as a light source, since the phototransistor is sensitive to visible light and has a narrow angle of view.

...two new components. Both new products are on the Components page.

The visible light phototransistor has a narrow field of view and high sensitivity to visible light. This makes it useful when using a laser beam as the light source for a photogate.

The 12-turn 1-megohm potentiometer is an upgrade to the 1-megohm potentiometer provided with a delay units. The 12-turn pot provides precise control of the delay time.

...an accessory item for flash units that don't have PC cords. The Flash-to-PC adapter provides a way to easily connect such flash units to the output of a trigger or delay unit.