VOM1271 driving two MOSFETs creating bidirectional solid state relay.
Fig. 1 VOM1271 driving two MOSFETs creating bidirectional solid state relay.


Build High Power MOSFET Bidirectional Switch Relay

by Lewis Loflin

Bidirectional solid state relays are had to find in particular for high power switching. Here we will build one.

Fig. 1 illustrates my bidirectional MOSFET relay-switch. It used a photovoltaic opto-coupler to drive dual N-channel MOSFETs.

VOM1271 driving two n-channel MOSFETs.
Fig. 2 VOM1271 driving two n-channel MOSFETs.


Fig. 2 is the schematic to the circuit in Fig. 1. The output voltage and current ratings depend on the two MOSFETs used.

PVT212 electrical connections.
Fig. 3 PVT212 electrical connections.


While Fig. 3 illustrates the possible connections for a PVT212 bidirectional SSR the same connections can be done with Fig. 2

Alternative Parts

The Vishey VOM1271T is available from Mouser Electronics for $2.33 each or $1.94 each Qty 10.

An alternative is the Toshiba TLP3906 $2.08 each or $1.69 each Qty 10.


© Copyright 2019 Lewis Loflin E-Mail