What is a Proximity Sensor?
An Electronic Proximity Sensor is a contactless sensor that determines the presence of any object within its vicinity when the target object enters the sensor’s field. Depending on the type of proximity sensor, sound, light, IR, or electromagnetic fields may be utilized by the sensor as a sensing medium to detect the target object. Today, we will go through a step-by-step procedure on how to build an IR Proximity sensor using the TSOP1738 IR Receiver so let’s get into it.
The heart of this circuit is the TSOP1738 IR receiver. TSOP1738 IR receiver can receive IR signals of 38KHz. The sensor operates on a 5V supply voltage & uses around 5mA to operate. It has the ability to read the output signals from IR devices such as TV remotes, Home theatre remotes, AC remotes, etc.
Hardware Components
The following components are required to make Proximity Sensor Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | IR Receiver Sensor | TSOP1738 | 1 |
| 2. | IR TV Remote (IR transmitter) | – | 1 |
| 3. | Transistor | BC557 | 1 |
| 4. | LED | 5mm/3.5V | 1 |
| 5 | Buzzer | 5V | 1 |
| 6. | Capacitor | 10uF | 1 |
| 7. | Resistor | 150 Ohm | 1 |
| 8. | Soldering Iron | 45W – 65W | 1 |
| 9. | Soldering wire with flux | – | 1 |
| 10. | Veroboard | – | 1 |
| 11. | DC Battery | 5V | 1 |
| 12. | Battery clip | – | 1 |
| 13. | Jumper Wires | – | As per need |
TSOP1738 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of TSOP1738
Proximity Sensor Circuit
Working Explanation
On breaking the line of sight between the IR LED & the TSOP1738 receiver, a control signal flows through the OUT terminal of the receiver to the base of the BC547 transistor. This control signal in turn triggers the LED & the buzzer, indicating that there is some obstruction between the IR transceiver’s line of sight.
Proximity Sensor
The working for the proximity sensor configuration is as follows, On bringing the target object within the vicinity of the sensor, the IR rays reflect from the surface of the object to the IR receiver. The output from the IR receiver acts as a control signal to the base of the BC557 transistor. The subsequent colleter output triggers the Buzzer & the LED.
Applications
- Generally used in home security appliances such as motion sensors & security alarms to keep your home safe from intruders & burglars.
