We are updating day by day with different projects. Now, here we are going to post a very simple project using a few active as well as passive components called dual switches. As its name, it can be used as a touch switch as well as heat operated switch. Thus, we are calling it Touch Switch Cum Heat Operated Switch
Circuit Description Touch Switch Cum Heat Operated Switch
The circuit of the touch switch cum heat operated switch is very simple and easily understandable. It comprises three general-purpose transistors.
The touch plate is connected to the base of transistor T1, when it is touched the relay is operated. Similarly, when the transistor is heated to about 800C the relay is energized. The transistor T1 can be replaced with any NPN transistor which 100 KΩ resistor connected to the collector.
Capacitor C1 and C2 are used to prevent the chattering sound. The load should be connected as shown in the circuit diagram. Transistor T3 is used as a relay driver.
Note:- Transistor T1 must be metal package type.
Check out other touch-operated switches posted in bestengineeringprojects.com
- Touch Switch Circuit using Transistor
- Clap Switch Cum Touch Switch
- Simple Touch Switch Using Two Transistor
- Thermal Touch Switch using op-amp 741
- Touch Dimmer Circuit
PARTS LIST OF TOUCH WITCH CUM HEAT OPERATED SWITCH
| Resistor (all ¼-watt, ± 5% Carbon) |
| R1 = 100 KΩ |
| Capacitors |
| C1 = 1 µF, 16V (Electrolytic Capacitor)
C2 = 100 µF 16V (Electrolytic Capacitor) |
| Semiconductors |
| T1 = BC177 (General Purpose Silicon PNP Small Signal Transistor)
T2 = BC108 (general purpose low power Silicon NPN bipolar junction transistors ) T3 = AC128 ((general purpose low power Germanium PNP bipolar junction transistors )) |
| Miscellaneous |
| RL1 = 6V, relay
Touch Plate |