User`s manual

SG-211 User’s Manual

4.4 The Relay Driver Matrix

Page one of the schematic diagram shows the matrix used

to drive the relay coils. The latching relays have two

coils; one for turn-on and one for turn-off. With 16 relays,

the circuit needs to drive 32 coils. A matrix of six

columns and six rows allows selection of 36 coils with

only 12 microprocessor outputs.