Temperature Control: Output

The final output of the programmer is the result of the reaction of the Amplifier, Transducer, Feedback Potentiometer, Vacuum Motor and Vacuum Relay to the input signal. The input signal is amplified by the amplifier resulting in a relatively strong current flow through the transducer coil that varies in accord with input signal changes. The transducer converts this received current flow to a proportional vacuum signal which is routed through the vacuum relay to the vacuum motor. The vacuum motor performs the following five output functions:

1. Positions the air-mix door.
2. Positions the wiper contact on the blower circuit board switch to obtain the required blower speed necessary for a selected mode of operation and temperature.
3. Controls mode door operation.
4. Controls heater water valve.
5. Controls recirculated air door.