Slotted switch allows non-contact object sensing

Designated the OPB200, the optically triggered switch contains an 890nm infrared LED and a phototransistor paired in an opaque plastic housing.

'By adapting the design of this switch to include a wider sensing gap and a lower board-mounted profile, we've expanded the range of applications where engineers can employ non-contact switching,' said Roland Chapa, vice president of optoelectronic integrated solutions for Optek.

'It is ideal for most types of machine automation circuits, especially for assembly line automation and machine safety/security applications,' he said.

When no object is present in the slot, the output phototransistor conducts current to maintain the circuit.

When an object enters the slot and blocks the beam of infrared light from the LED, the output switches to the OFF state to interrupt the circuit.

The device housing is constructed of opaque injection-molded plastic to minimise the sensitivity of the assembly's optical components to ambient visible and near-infrared light, enhancing performance.

The OPB200 switch exhibits a forward voltage of 1.7V (max) at IF = 20mA; with a reverse current of 100uA (max) at VR = 2V.

Collector-emitter breakdown voltage is 30V (min) at IC = 1mA; with emitter-collector breakdown voltage of 5V (min) at IE = 100uA.

Collector dark current is 100nA (max).

Collector-emitter saturation voltage is 0.4V (max); and the on-state collector current varies from 1mA (min) to 6mA (max).

Operating temperature range is -40 to 85C.

The OPB200 slot measures 0.200in/5.1mm wide, with a depth of 0.320in/8.1mm, and the overall board-mounted profile of the device is 0.4in/10.16mm.

Lead length is 0.425in with spacing of 0.4in.