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Assembly and Operating Instructions for Kits


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Connection Options for Flash and Camera


PC jack on side of flash unitConnecting to a flash unit

Connecting the output of a trigger circuit to a flash unit is the choice to make when you want the most rapid response. One such situation is for photographing balloon bursts, which take only a few thousandths of a second. If you connected the sound trigger to a camera, the burst would be over by the time the shutter opened due to the shutter lag that all cameras have. Even if the camera manufacturer advertises the shutter lag as small, that claim assumes you're doing normal motion photography rather than high-speed photography.


A similar consideration as for cameras applies to triggering a wireless transmitter. Transmitters introduce a lag time of a few thousandths of a second. If that lag time is important, then you should trigger a flash unit directly.


Our kits don't include the connector for your flash unit, since the type of connection is different for different units. Some flash units have a PC jack (see photo to right) so that a standard PC cord can be used. The Vivitar models 83/285HV/3700 have a propietary jack, so a special cord is required for those units. If your flash unit doesn't have a jack, then you can probably use a hot shoe adapter that has either a PC cord or a PC jack on the side. Be wary of flash units that are designed for on-camera use only or with a proprietary wireless system. It may not be possible to trigger such units through the hot shoe. An example of one such flash unit is the Nikon SB-400. This flash unit will not work with our trigger circuits.


The table below is designed to help you select a flash trigger cord. The Connector Type refers to the connection to the breadboard or trigger enclosure.


Kit type Product code Connector Type
(Click on the links for cable options)

Breadboard kits

all breadboard kits
except the CBP-O
bare wires1


enclosure kits


MT2, MT3



1See this table for connection points of flash units and wireless controllers to breadboard circuits.

2The SK3 has been continued.



Connecting to a camera

There are some situations where it's preferable or necessary to trigger a camera rather than a flash unit. One such situation is if you're photographing birds in daylight using a crossed-beam photogate and have to keep the exposure time to a minimum. Another application is for splash photography. The immediate output of a delay unit can be used to actuate the camera, and the delayed output then actuates the flash.


This DIY method can be used to connect a camera to our breadboard circuits. This method, however, doesn't provide complete electrical isolation between the trigger circuit and your camera. If you want the assurance of knowing that your camera circuitry is isolated from the trigger, you would use an optical isolation method. Our Camera Opto-Switch provides such isolation. Our breadboard circuits require the Opto-Switch for optical isolation. However, several of the circuits have optical isolation built in. These include the Multi-Trigger 2 and 3 (MT2/3) and the Crossed-Beam Photogate (CBP-O and CBP2).


The table below tells whether a Camera Opto-Switch is or not your trigger requires an Opto-Switch, you'll need a shutter cable to connect to your camera. Click here for a list of shutter cables that we have available.


Kit type Product code Camera Opto-Switch
(required for camera triggering)

Breadboard kits

All breadboard kits except the CBP-O yes1
CBP-O no
PCB kit




enclosure kits

MT2, MT3

SK3 yes
CBP2 no


1See this table for connection points of the Opto-Switch to breadboard circuits.




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