You went to make a panic plate circuit you need some component, Touch plate, IC(7555), IC(CD4017), UM66,7805, transistor BC548, capacitor, diode, and some resistors then you can make this circuit. This is a touch-sensitive circuit, it’s very useful for the elderly and ailing person. This touch-sensitive circuit sounds a panic alarm to get the care of others for live help.
≡ Component and working details:-
- Resistors: In this circuit, we use 68 ohms,82 ohms, 220 ohms,100 ohms,100k resistors.
- Capacitor: Capacitor two-terminal electrical component and is used to store electrostatic energy in an electric field. In this circuit, we use 0.1uf, 100uf,10pf.
- Transistor: In this circuit, we use two BC548 transistors. It’s a general-purpose BJT NPN Transistor. BC548 transistor has 3 pins 1-Collector, 2-Base, 3-Emitter. Current flows in the collector, the biasing of the transistor are controls by the Base, Current Drains out through the emitter.
- 7555(Timer IC): In this circuit, we use 7555 IC. The 7555 timer is a CMOS RC low-power devices. In this IC is available 8 pins . 1 pin is used to ground, 2 pin is the trigger, 3 is used to an output pin, 4 is the reset pin, control voltage pin is 5, 6 is the threshold pin, 7 is discharge pin and 8 number pin is used to +Vcc. 7555 IC power supply range 2V to 18V.
- Diode: In this circuit, we can use a diode (1N4148). A diode allowed to an electric current to pass in one direction and it used to convert alternating current(AC) to direct current(DC).
- IC (CD4017): We used IC (CD4017) in this circuit. This IC has 16 pin available , pin number 3,2,4,7,10,1,5,6,9,11 is decoded output . Pin number 8 is the ground supply voltage,12 pin is the carry output,13 clock input(HIGH to LOW edge trigger,14 clock input(LOW to HIGH edge trigger ), 15 pin is the master reset input,16 supply voltage. The supply voltage range of the IC is 3V to 15V.
- IC 7805: In this, we used LM7805 voltage regulator IC. This voltage regulator IC has available 3 pins, 1 number pin input (v+), 2 number pin ground, and number 3 pin output regulated +5V. This IC Input supply voltage range is 7V to 25V.
- UM66: UM66 used in this circuit, this IC has 3 pins. Ground, positive power supply, and output. This IC lower range of operating voltage from 0.3V to 3.5V. We can easily drive a speaker through the NPN transistor used in this IC.
- Touch Plate: A touch plate consists of a plate of a special color beyond the traditional cyan, magenta. In this circuit, we used a touch plate 15*15 cm.
≡ Panic Plate Circuit Using CD4017 Circuit and PCB:-
≡ How to work this circuit:-
The circuit Work based on the electric charge in the human body. When the sensor plate touched then the electric charge present in the body biases transistor and triggers the IC 7555 and its output goes high for a while. The signal pulse from 7555 triggers IC CD4017, which is a decade counter IC. When IC2(CD4017) receives the clock pulse from IC 7555 through output goes high to power LED and melody generator IC(UM66). UM66 IC is amplified by transistor T2 and heard from the speaker. And if IC2 receives another clock pulse its Q2 output goes high and stops the alarm tone and red light indicates the need for care. The first touch will make a call, the second touch will stop the call and the third touch will reset the IC.
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