The HiViz WorkShop
SPG1 / SPG2. Schmitt Trigger Photogate Kits, Unassembled
Above: An assembled Schmitt trigger photogate kit with separate emitter and detector (the SPG1 option). Click on the photo for a larger view.
Below: The interrupter-style emitter-detector that is included with the SPG2 option. It replaces the separate emitter-detector pair of the SPG1.
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The Schmitt Trigger Photogate (either the SPG1 or SPG2 described below) uses a 555 timer, which provides a clean output signal to trigger a flash unit.
SPG1. The matched infrared emitter and detector have separate housings. This allows the two parts to be placed different distances apart, depending on the application. The maximum separation is about a foot (30 cm). If your application requires greater separations, a red laser pointer can be substituted for the infrared LED.
SPG2. The emitter and detector are housed in a single interrupter-style unit. The interrupter, shown to lower right, has a slot of fixed width between the emitter and detector posts. The separation of the posts (5/8" or 1.5 cm) is wider than for most interrupters. This is large enough for liquid drops and small projectiles to pass.
The kit includes three feet of 2-conductor cable for splicing the output to a PC cord or Flash-to-PC adapter. The latter two items are not provided with the kit but can be purchased separately. See the Product Guide for various connection options. In order to trigger a camera, see the Camera Opto-Switch or this DIY method.
A 9-V battery or 9-V AC/DC Adapter is required to power the circuit.
The kit does include 3 feet of 3-conductor cable to move the emitter-detector pair to a location away from the breadboard.
An electronic delay unit is commonly used with the photogate to achieve timing synchronization. You receive a $1.00 discount when purchasing an SPG trigger with a delay unit. To order this combination, go to this page.
When purchasing a SPG kit with a breadboard, there is a $1.00 savings over buying a kit and breadboard separately.
Purchase this kit assembled. Click here for more information or below to order.
Purchase this kit assembled. Click here for more information or below to order.
