Articles added in Mathematics Lab | Cyber Lab is now open | Astronomy Lab is now open | VLSI Lab is now open | 120 SEO Tips article published | More exciting articles coming soon!

# Temperature controller using 8085

• Temperature measurement is used in variety of applications like furnace, water bath, oven, etc. with the help of transducers like thermocouple.

• The output of thermocouple is proportional to temperature which is in milliVolts. Therefore to drive further stages of system, this signal is amplified using instrumentation amplifier.

• The amplified output is fed to channel 3 of ADC and 8085 provides High to Low SOC and ALE signal.

• When ADC completes the conversion, 8085 reads the equivalent digital data from Port A which is the current value of temperature of object.

• This value of measured temperature is then sent to display system.

• For measuring temperature of furnace, water bath, etc. 8085 1st measures current temperature (t1) and compares with the reference temperature (T1) at which the temperature is to be kept constant.

• If the measure temperature (t1) is greater than reference temperature (T1) then 8085 sends control signal to the transistorized relay circuit through Port B and turns OFF the heating process to maintain temperature at desired level.

• If the measure temperature (t1) is less than reference temperature (T1) then 8085 sends control signal to the transistorized relay circuit through Port B and turns ON the heating process to maintain temperature at desired level, thus maintaining the temperature of furnace, bath tub, etc.

• Chips select Logic:

Control word Format: =98H

Data for channel selection:
=0BH (SOC= HIGH)

=03H (SOC= LOW)

Data for turning Heater ON/OFF:
=00H (Heater OFF)

=01H (Heater ON)

Program:

## Interfacing Diagram

CACKLE comment system