We are updating day by day with different projects. Now, here we are going to post very simple project using few active as well as passive components called dual switch. As its name, it can be used as touch switch as well as heat operated switch.
Circuit Description Touch Switch Cum Heat Operated Switch
The circuit of heat switch cum heat operated switch is very simple and easily understandable. It comprises three general-purpose transistors.
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 collector.
Capacitor C1 and C2 is used to prevent the chattering sound. The load should be connected as shown in circuit diagram. Transistor T3 is used as relay driver.
Note:- Transistor T1 must be metal package type.
PARTS LIST OF TOUCH WITCH CUM HEAT OPERATED SWITCH
|Resistor (all ¼-watt, ± 5% Carbon)|
|R1 = 100 KΩ|
|C1 = 1 µF/16V|
C2 = 100 µF/16V
|T1 = BC177|
T2 = BC108
T3 = AC128
|RL1 = 6V, relay|