Cell Phone Call & SMS Alerter using CA3140

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In this DIY, we are going to demonstrate Cell Phone Call & SMS Alerter Circuit. The figure shows a project of mobile phone calls and SMS alert circuits. A few times we can’t hear the ring tone or SMS tone of our mobile phone when they are in another room and we miss the significant call or SMS, and after few hours when we check the phone then we understand that it is late. The circuit appeared here will take care of that issue by flashing the LEDs and enact a buzzer while putting it close to your phone. One of the important features of the circuit is that it will stay activated for 5 minutes after the call is missed or SMS is received.

The circuit has additionally numerous different uses as it very well may be utilized with the mobile phones with moderate ringtones and when your cell phone is on vibration due somebody is resting in the room. For that reason you can remove the buzzer and make the circuit to alert. The circuit can also be utilized for individuals with hearing issues like or deaf people groups.

Hardware Components

S.no	Components	Value	Qty
1	IC	CA3140	1
2	IC	NE555 Timer	2
3	Transistor	2N3904	1
4	Diode	1N34	2
5	Piezo Buzzer	–	1
6	LED	–	6
7	Resistor	1K, 100KR, 10K, 1M, 470R	1, 1, 2, 2, 6
8	Capacitor	0.1µF, 10µF, 220µF	1, 1, 1
9	Battery	9-12V	1

Circuit Diagram

Circuit Operation

In this section, we explain the circuit operation of the circuit. The circuit is utilizing 3 ICs and other discrete parts. The enactment time of the circuit is 5 minutes and after that time, automatically it will go off. The actuation time can be increase or decreased by expanding or diminishing the estimation of the 220uF capacitor labeled as “Cx”. The 100K variable resistor is used to modify the speed of LEDs flashing. The working voltage of the circuit is 9V to 12V DC.