This ppt is regarding a application of SCR where SCR is used for temperature controller.

1. TEMPERATURE
CONTROLLER

2. What is Temperature Controller?
A Temperature Controller is a
device that is used to control a
heater or other equipment by
comparing a sensor signal with a
set point and performing
calculation according to the
deviation between those values.
Devices that can handle sensor
signals other than for temperature
Such as humidity, pressure, and
flow rate are called Controllers.
Electronic controllers are specially
called Digital Controllers.

4. Temperature Controller Circuit

5. OPERATION :
 In this arrangement, a diode bridge rectifier is connected to
the ac supply through heater.
 This results in a full wave rectified voltage across the thyristor
T1.
 When the thermostat is open, the voltage across the capacitor
C1, triggers the thyristor T1, in each half cycle of the input
supply and the current flows through the heater.
 The charging time constant depends on the product of the R1,
and C1, network.
 As the temperature increases, the conductive thermostat short-
circuits the capacitor, and this eliminates the possibility of the
capacitor charging to trigger the thyristor.
 As a result, no current flows through the heater.

6. Use of Temperature Controller
Temperature controller is a
device that is used to control the
temperature of devices, rooms,
electronics components etc. by
monitoring the temperature.
The circuit can be used for car
Engine to reduce the heat.
Cooling Pads in Computer/Laptop.
In the process control of chemical reactions, temperature
control is of major importance, since chemical reactions
are temperature dependent.