Fig. 1

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.


Fig. 2

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

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.





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