Thursday, July 23, 2009

Build Your Own High Voltage Optocoupler

Have you ever needed an optocoupler or isolator but couldn't find what you needed? If so, you might have an interest in Voltage Multipliers' new OZ100SG 10kV opto-diode. This device makes it possible to build your very own high voltage opto-coupler using your choice of LEDs as a light source. Simply reverse bias the photo-diode, run forward current through one or more LEDs (thus exposing the photo-diode junctions to light), and monitor the leakage current, Ir. The level of leakage current serves as feedback for forward current through the LED, while providing system isolation. For more information see Voltage Multiplier OZ100SG

The OZ100SG represents a breakthrough in opto-diode technology. Capable of operating at up to 10,000 volts reverse bias (10kV Vrwm) is it comprised of multiple silicon junctions. The key to operation is light sensitive junctions. Molded in optically clear epoxy, the OZ100SG is a light-sensitive device. When exposed to light, leakage current, Ir, is the result. Leakage current is directly proportional to light intensity, so by varying forward current through the LEDs, light intensity from the LED will vary.

Varying light intensity in the LEDs results in a corresponding variation in Ir in the photodiode. Ir typically ranges from 1uA to 1nA range. Controlling the exposure to light makes it possible to control leakage current in the photo-diode, thus providing a closed feedback loop. This makes for a useful way to remotely monitor electronically sensitive systems.

Other light sources can be used to generate leakage current in the photodiode.

Applications include

• High Voltage Switches and Remote Control Circuitry

• HV Linear Regulators

• Spectroscopy

• Pockels Cells