Basic Electronics

Mobile Phone Detector with UTSOURCE service


Mobile Phone Detector

The most powerful portable electronic gadget a person can control today is a cell phone or mobile phone. The demand for Mobile phones shown tremendous rapid growth in recent years drastically. The Mobile phone can transmit and receives the signal in the range of 0.9-3 GHz.

Mobile Phone Detector

Principle of Mobile phone detector:

The basic principle of cell phone or mobile detector is to detect the RF signal frequencies. These circuits are designed in such a way that it rectifies low signal frequencies with very low noise of rate. When an inductor is placed near a RF signal frequency source it receives the signal through the principle of mutual induction. And the low power signals are amplified and transmit the power to any indicator which shows the response as we have used LED in our experiment.

This can be really a fun project, using this small electronics circuit we can detect if someone is sending or receiving a message, or call is coming or someone is trying to call someone. As you can see in the picture above just a few electronic components are required for this project. Nothing expensive is used in this project. This project is ideal for school students and anyone can build this amazing small project in the lab.

After the basic working principle is understood, then the led can be replaced with a transistor to control a relay which can then control a buzzer. So, when anyone sends a message or receives a message the buzzer will turn ON.

Components Required for the mobile/cell phone detector:

  1. CA3130 Integrated Circuit (IC)
  1. 1k ohm resistor (1)
  1. 100k ohm resistor (1)
  1. 2M ohm resistor (2)
  1. 47pF Capacitor (1)
  1. 22 microF Capacitor (1)
  1. 100microF Capacitor (1)
  1. BC548 Transistor (1)
  1. LED (1)
  1. 9v Battery
  1. 9v Battery Clip
  1. Connecting wires (as required)
  2. Bread Board

Circuit Diagram of the mobile phone detector:

Mobile Phone Detector

Step by step procedure:

  1. Insert CA3130 on the breadboard

Mobile Phone Detector

Before, I am going to explain the rest of the connections; first I would like to explain the IC CA3130.

About the CA3130:

CA3130 and CA3130A are op-amps “Operational amplifiers” that combine the advantage of both CMOS and bipolar transistors.

Gate-protected P-Channel MOSFET (PMOS) transistors are used in the input circuit to provide very-high-input impedance, very-low-input current, and exceptional speed performance. The use of PMOS transistors in the input stage results in common-mode input-voltage capability down to 0.5V below the negative-supply terminal, an important attribute in single- supply applications.

The CA3130 Series circuits operate at supply voltages ranging from 5V to 16V, (2.5V to 8V). They can be phase compensated with a single external capacitor and have terminals for adjustment of offset voltage for applications requiring offset-null capability. Terminal provisions are also made to permit strobing of the output stage.

CA3130 Pinout:

Mobile Phone Detector

Download CA3130 datasheet

Absolute Maximum Ratings

DC Supply Voltage (Between V+ And V- Terminals) . . . . . . . . . .16V

Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8V

DC Input Voltage . . . . . . . . . . . . . . . . . . . . . . (V+  +8V) to (V- -0.5V)

Input-Terminal Current. . . . . . . . . . . . . . . . . . . . .  . . . . . . . . . . . 1mA

Output Short-Circuit Duration (Note 1). . . . . . . . . . . . .  . . .  Indefinite

Operating Conditions

Temperature Range. . . . . . . . . . . . . . . . . . . . . . .  . . -50C to 125C

  1. Connect pin 7 to the positive rail

Mobile Phone Detector

  1. Connect pin 4 to the negative rail of the bread board

Mobile Phone Detector

  1. Now we insert the BC548 transistor on the Breadboard

Mobile Phone Detector

  1. Now connect pin 6 to the base of BC548

Mobile Phone Detector

  1. Connect the collector of Bc548 to the positive rail using a 1K ohm resistor.

Mobile Phone Detector

  1. Now insert the LED light on the BreadBoard circuit with the Anode connected to the emitter of BC548 and cathode connected to the negative rail.

Mobile Phone Detector

  1. Connect pin 2 to the base of BC548 using a 2.2M ohm resistor

Mobile Phone Detector

  1. Connect pin 3 to the negative rail using a 100k ohm resistor.

Mobile Phone Detector

  1. Insert the 100micro F capacitor with one of its pin connected to the anode of the capacitor to the pin 3 and its cathode to the negative rail.

Mobile Phone Detector

  1. Connect pin 3 to the positive rail using a 2.2M ohm resistor.
  2. Now connect pin 2 of the breadboard and another pin 3 with the 0.22micro Farad capacitor.

Mobile Phone Detector

  1. Now Connect pin 1 of IC to the pin 8 using the 47pF capacitor.

Mobile Phone Detector

  1. Connect the power supply to the breadboard of the circuit.

Mobile Phone Detector

Testing of the circuit with the mobile connecting operation:

When we make a call from our phone (outgoing call)  the LED of the circuit starts blinking till the phone rings.

Mobile Phone Detector

And when a phone call comes to our phone ( Incoming call) the LED also blinks. As you can see

Mobile Phone Detector

And we reject the call it stops blinking. It also works when a person sends a message to someone as you can see an outgoing text message.

Till the message goes it blinks and stops when it sends to the receiver. And same applies when it receives the message it starts blinking (Incoming text message).

Mobile Phone Detector

So this circuit works flawlessly when the user sends or receives messages or calls to anyone. Reviews

It is a trustworthy website for ordering electronic components to complete projects, free shipping can be provided on selected order for a 2-5 days delivery.

Mobile Phone Detector


The mobile phone detector works when the phone receives and outgoing calls and messages. This circuit works completely well to detect the signals of the phone simulations and all.


Engr Fahad

My name is Shahzada Fahad and I am an Electrical Engineer. I have been doing Job in UAE as a site engineer in an Electrical Construction Company. Currently, I am running my own YouTube channel "Electronic Clinic", and managing this Website. My Hobbies are * Watching Movies * Music * Martial Arts * Photography * Travelling * Make Sketches and so on...

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