Fig. 2 shows a simple motor control circuit that will only allow the motor to start — and remain running — when its lube oil pump is running, at least one valve is open, and no alarms exist. Pressing ...

With this circuit, you can use low-torque, low-revolutions-per-minute stepper motors in systems in which you formerly needed dc gearbox motors. By changing the pushbutton to a dpdt switch, you can ...