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Entry-Master Option-4 Hardware Installation Guide
Appendix A. Using the Transistor Outputs
While the use of transistor outputs may seem confusing, it can really be summed up in
one simple fact: "... the collector always drops to ground when the transistor is
activated."
The "collector" is the middle pin of the 3-pin connector for either transistor output on an
Option-4 board. There are three (3) ways of utilizing the transistor output: in the first
method, the Option-4 board actually powers the locking mechanism, providing voltage to
the lock coil. In this case, only the collector (C) and (+V) connectors are utilized (See
Figure 1 below).
When the transistor output is not active, the collector "hovers" at a voltage close to +V.
But when the transistor output switches to "active" the collector essentially "drops" to
ground, creating a voltage potential between the collector (C) and (+V) pins, thus
providing power to the locking mechanism.
