T4 applies V D across R5 and R6, which puts 10V at A, keeping T2 latched on, and switches T1 on draining C3’s charge through R2 and leaving 0V at the open PB switch ready for the shut off switch ...

open or close gates/doors, or provide notification to remote locations. With both momentary and maintained contact options, the switches offer wireless control from both person and position. The user ...