Ir Sensor Circuit Diagram. The passive infrared sensor consists of three pins as shown below. And non inverting end pin 3 is connected to the junction of photodiode and a resistor.
You can use any tsop but you need to generate ir of respective frequency as tsop. Pin1 pin2 and pin3 are corresponded to drain source and ground terminal of the device. The passive infrared sensor consists of three pins as shown below.
This circuit is mainly used for obstacle detection using an ir led.
So when an object comes to the ir sensor the amount of ir rays from the ir transmitter falls on the ir receiver increases and therefore the voltage at the resistor increases. As we know oscillation frequency of 555 timer is decided by. For npn bc547 transistor is used whereas for pnp bc557 transistor is used. So we are using 555 timer in astable mode to oscillate the ir at 38khz frequency.
