The electronic thermostat discussed here enables you to control the room temperature by properly switching (switching on and off) a heating device.
Functional information of electronic thermostat
The circuit uses a thermistor NTC (negative temperature coefficient) as the sensor device.
- Provided that the ambient temperature remains more than the value prefixed by the potentiometer, the relay in the same way stays inactivate and the red LED could be observed lit up.
- In an occasion of the ambient temperature acquiring less than the set value, the relay is switched on and the green LED is lighted.
The potentiometer should be cautiously modified to be able to obtain the preferred results.
To adjust the offered transistor thermostat circuit, the NTC is enclosed inside a glass tube and its leads are shut down out by means of long wires to ensure that it may be located over the preferred location for the needed sensing.
The circuit is placed by setting the thermistor glass tube in addition to a mercury thermometer inside a container full of melting ice water, as well as in the subsequent process its positioned at ambient temperature last but not least near to a gas burner for applying all the setting levels.
In each of the previously listed instances, the purpose in which the green LED just illuminates is situated by delicately manipulating the pot knob toward the maximum and taking note of it with a line over the knob dial to be able to create the appropriate temperature calibrations, these types of markings are then effectively labelled with the specific temperatures that happen to be documented at the same time on the connected thermometer.
The circuit procedure is pretty simple which enable yo to be realized by evaluating each transistor cut off and activating states.
For provided that the NTC resistance is extremely high (when the ambient temperature is low) brings about the transistor T1 to move into saturation supplied the potentiometer setting allows this.
Thinking about the above circumstance is allowed the transistors T1 T2 T3 and T4 saturate as well as switch on the relay.
The relay utilized could be a double contact and each time it is started two procedures are implemented, one pair of contacts to switch the LEDs along with the other to switch on the heater or the preferred load.
The capacitor C1 makes certain unexpected improvements in the value of the NTC.
Bill Of Material for the above transistor thermostat circuit:
- Resistors: R1, R4, R6: 10K, R2: 12K, R3: 6.8K, R5: 33K, R7: 470K, R8: 2.2K, R9: 560 ohms.
- Potentiometer: Linear 10K.
- NTC: Negative temperature coefficient 10K.
- Capacitors: C1: 100nF, C2: 47uF, 10V (electrolytic capacitor).
- LEDs: 1 red, 1 green
- Transistors T1 and T3: 2N2222, T2: 2N2907, T4: 2N2905
- Relay: 12V DPDT.
Functional information of electronic thermostat
The circuit uses a thermistor NTC (negative temperature coefficient) as the sensor device.
- Provided that the ambient temperature remains more than the value prefixed by the potentiometer, the relay in the same way stays inactivate and the red LED could be observed lit up.
- In an occasion of the ambient temperature acquiring less than the set value, the relay is switched on and the green LED is lighted.
The potentiometer should be cautiously modified to be able to obtain the preferred results.
To adjust the offered transistor thermostat circuit, the NTC is enclosed inside a glass tube and its leads are shut down out by means of long wires to ensure that it may be located over the preferred location for the needed sensing.
The circuit is placed by setting the thermistor glass tube in addition to a mercury thermometer inside a container full of melting ice water, as well as in the subsequent process its positioned at ambient temperature last but not least near to a gas burner for applying all the setting levels.
In each of the previously listed instances, the purpose in which the green LED just illuminates is situated by delicately manipulating the pot knob toward the maximum and taking note of it with a line over the knob dial to be able to create the appropriate temperature calibrations, these types of markings are then effectively labelled with the specific temperatures that happen to be documented at the same time on the connected thermometer.
The circuit procedure is pretty simple which enable yo to be realized by evaluating each transistor cut off and activating states.
For provided that the NTC resistance is extremely high (when the ambient temperature is low) brings about the transistor T1 to move into saturation supplied the potentiometer setting allows this.
Thinking about the above circumstance is allowed the transistors T1 T2 T3 and T4 saturate as well as switch on the relay.
The relay utilized could be a double contact and each time it is started two procedures are implemented, one pair of contacts to switch the LEDs along with the other to switch on the heater or the preferred load.
The capacitor C1 makes certain unexpected improvements in the value of the NTC.
Bill Of Material for the above transistor thermostat circuit:
- Resistors: R1, R4, R6: 10K, R2: 12K, R3: 6.8K, R5: 33K, R7: 470K, R8: 2.2K, R9: 560 ohms.
- Potentiometer: Linear 10K.
- NTC: Negative temperature coefficient 10K.
- Capacitors: C1: 100nF, C2: 47uF, 10V (electrolytic capacitor).
- LEDs: 1 red, 1 green
- Transistors T1 and T3: 2N2222, T2: 2N2907, T4: 2N2905
- Relay: 12V DPDT.
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