This is simple infrared receiver for the burglar alarm system or the others protection, etc.It use a few components that there are most common transistors and photodiode is received infrared signal.
From Infrared Remote control transmitter by IC-555-BD137. Let’s build the Infrared receiver circuits. Which has too much circuits. Starting from a simple circuits as Figure 1 first.
We will see that a photodiode is connected in the reverse bias form. So, while infrared light to hit it. It has very little current through it.
But when has the infrared light from the light will cause the current to flow through the diode is good. Cause a voltage signal to the frequency of the signal transmitter set to transistor TR1(BC549). Which is connected with TR2(BC557) are a amplier circuit about 1000 times.
Both capacitors C2,C3 are the high pass filter circuit.
Two diode D2(1N4148),D3(1N4148) act as the convert AC voltage signal to DCV. By has C5 is filter current to smooth.
The voltage output drive transistor TR3 to the relay works.
The relay so work when has the infrared light from the transmission to the receiver. If the beam is cut or obscured. Relay will stop working.
Figure 1 The simple Infrared receiver circuits
This circuit is suitable for use in the burglar alarm system or the others protection, etc.
Figure 2 the PCB layout and components layout of simple infrared receiver.
The component list
Q1____BC549____45V 100mA NPN Transistor
Q2____BC557____45V 100mA PNP Transistor
RY1___Relay 12V coil
D1,D2____1N4148____75V 150mA Diodes
D5,D6__1N4001____1A 50V Diodes
C1____0.022uF 50V Ceramic capacitors
C2____100uF 25V electrolytic capacitors
C3____0.01uF 50V Ceramic capacitors
C6____2.2uF 25V electrolytic capacitors
C7____470uF 25V electrolytic capacitors
R1____22K 1/4W Resistors