A closed loop remote control system is an electronic device that automatically regulates a system to maintain a desired state or set point without human interaction. It uses a feedback system or sensor. Closed loop control is contrasted with open loop control, where there is no self-regulating mechanism and human interaction is typically required.
The setup consists of a small furnace is controlled by FM based remote operation. A Thermocouple is used for measurement of temperature and its millivolt output is enhanced by an Amplifier. The amplifier output directly fed into the FM modulated circuit. The information carried over remotely placed ( about 20 meters ) Receiver.
At the receiver end, the demodulated portion decodes the information, amplifies and display. As per information the modulator at the receiver end transmit another FM wave to the controller of the transmitter for taking necessary steps.
The FM wave control the Thyristor drive control circuit as well as furnace temperature.
The system contains two Transreceivers :
- Transreceiver 1 :
- Muffle Furnace : 800ºC.
- Thyristor Drive Furnace Controller.
- Thermocouple 2 Nos.
- Thermocouple Signal Conditioner.
- Amplifier.
- FM Transmitter.
- FM Receiver.
- Transreceiver 2 :
- FM Receiver
- FM transmitter
- Amplifier
- Frequency to Voltage converter
- Temperature indicator
- PID Control Circuit
- MilliVolt Generator :
- Variable power supply : 0 to 1000 mV
- Digital Voltmeter : 3 ½ Digit LED Display , 0 – 2000 mV
- Additional Accessories Required :
- Dual Channel Oscilloscope (20 MHz)