These position sensors (Reed-Type indicators) with trim assemby consisting of a red LED that lights up when your electro pneumatic valve is in the open position. These position sensors are an indicator that tells you when the valve is open.

Wiring - When wiring these reed switches you will need to include a series current limiting resistor to limit the amount of current that will flow through the LED, maxium 20 mA. For example, Reed switches operating on 115 VAC could use current limiting resistors from the range of 2.7 kOhm resistor (2 watts) up to 50K ohm (1/4 watt). For this example, we recommend using 50 kOhms at 1/4 watt.

The correct resistor value for a particular voltage can be determined from the following formula:

R = 50 (E - 2)

R is the Resistance and E is the operating voltage. Thus for a 12 VDC power source, the correct resistor value would be:

R = 50 (12 - 2) = 500 Ohm. Select the nearest standard value of resistance, in this case a 470 Ohm resistor.

When operating a LED from an AC voltage the current flows only for one half cycle, so to get the same effective brightness level use formula: R = 25 (E - 2.7) For 24 VAC power source this would be 532 Ohm. A 560 Ohm resistor would be used, the closest standard value.

DC Examples: 5 VDC (150 Ohm), 6 VDC (180 Ohm), 12 VDC (470 Ohm), 24 VDC (1.2 kOhm)

AC Examples: 6 VAC (82 Ohm), 12 VAC (220 Ohm), 24 VAC (560 Ohm), 48 VAC (1200 Ohm), 120 VAC (2700 Ohm).

Mounting - Slide the reed switch into one of the grooves of the pneumatic valve. Turn on the valve and move reed switch up and down until the reed switch position red indicator lights up. Tighten set screw when position is found.