Diode VS Thermistor - New Electronics Project (2021)

Do you thinking to make mini temperature sensor circuit at home? But you don’t have any ideas about making a cheap and simple temperature sensor circuit. Then this project is only for you.

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Today we’ll use two electronics components to test the temperature sensor circuit. We use a rectifier diode and thermistor (TTC-103). We also, need any more electronics component to make this circuit.

To make a diode sensor circuit we need –

1. Transistor – BC 547 *2

2. Resistor – 1 MΩ

220 Ω

3. Diode – 1N 4007

4. Buzzer

5. Battery – 3.7v

To make Thermistor sensor circuit we need –

1. Transistor – BC 547

2. Resistor – 1 KΩ

3. LED – 3.7v

4. Thermistor (TTC) - 103

5. Battery – 3.7v

BC - 547 Transistor Pinout

BC 547 is an NPN transistor. As usual BC-547 transistor also have 3 legs. These 3 also have different names. If I count its leg from the left side, then 1no "Collector", 2no "Base" & 3no "Emitter".

Circuit Connection - Diode Make Sensor

To make a diode sensor circuit 1st we connect 1 transistor “Emitter” with another transistor “Base”. Then we connect both transistor “Collector” and connect 220 Ω resistor with “Collector”. Now we connect the rectifier diode with the circuit. Connect diode negative leg with the empty terminal of 220 Ω resistor and diode positive leg with “Base”.

Now we connect buzzer with the circuit. We connect buzzer positive leg with “Emitter”. Then we connect 1 MΩ resistor with the circuit. We connect resistor with diode positive leg and buzzer negative leg.

Now, we connect power source with the circuit. You know, for power source we are using DC - 3.7 volt battery. Connect DC positive cable with “Collector” of transistor and DC negative cable with buzzer negative leg.

Our circuit is now ready for use. Now we just heat on the diode, if we hear the buzzer sound then we try to cold the diode and then the buzzer sound will be off.

Following this method, we can easily make diode control temperature sensor circuit at home easily.

To make thermistor sensor circuit, 1st we connect 1 KΩ resistor with “Base” & “Emitter” of the transistor. Now we connect the LED negative leg with “Collector” of transistor. Now we connect thermistor with the circuit. Connect thermistor with “Base” of transistor and another terminal with the positive leg of the LED.

Now we connect power source with the circuit. For power source we are using DC - 3.7 volt battery. Connect battery positive cable with positive leg of LED and connect battery negative cable with “Emitter” of transistor.

Our circuit is now ready for use. Now we just heat on the thermistor, if we see that LED light glowing then we try to cold the thermistor and then the LED light will be off.

Following this method, we can easily make thermistor control temperature sensor circuit at home easily.