Source: http://www.aaroncake.net/
I have received a number of emails requesting schematics for infa-red remotes. So here is one. This remote transmits a tone using an infa-red LED. This tone is decoded by the receiver. Since the receiver only switches when it "hears" the tone, there are no accidental activations.
Part |
Total Qty. |
Description |
Substitutions |
R1 |
1 |
22K 1/4W Resistor |
|
R2 |
1 |
1 Meg 1/4W Resistor |
|
R3 |
1 |
1K 1/4W Resistor |
|
R4, R5 |
2 |
100K 1/4W Resistor |
|
R6 |
1 |
50K Pot |
|
C1, C2 |
2 |
0.01uF 16V Ceramic Disk Capacitor |
|
C3 |
1 |
100pF 16V Ceramic Disk Capacitor |
|
C4 |
1 |
0.047uF 16V Ceramic Disk Capacitor |
|
C5 |
1 |
0.1uF 16V Ceramic Disk Capacitor |
|
C6 |
1 |
3.3uF 16V Electrolytic Capacitor |
|
C7 |
1 |
1.5uF 16V Electrolytic Capacitor |
|
Q1 |
1 |
2N2222 NPN Silicon Transistor |
2N3904 |
Q2 |
1 |
2N2907 PNP Silicon Transistor |
|
Q3 |
1 |
NPN Phototransistor |
|
D1 |
1 |
1N914 Silicon Diode |
|
IC1 |
1 |
LM308 Op Amp IC |
|
IC2 |
1 |
LM567 Tone Decoder |
|
LED1 |
1 |
Infa-Red LED |
|
RELAY |
1 |
6 Volt Relay |
|
S1 |
1 |
SPST Push Button Switch |
|
B1 |
1 |
3 Volt Battery |
Two 1.5V batteries in series |
MISC |
1 |
Board, Sockets For ICs, Knob For R6, Battery Holder |
|
RELAY |
1 |
6 Volt Relay |
1. To adjust the circuit, hold down S1 while pointing LED1 at the receiver. Adjust R6 until you hear the relay click.
2. You can increase range by using a high output LED for LED1.
3. Bright light will stop the receiver from responding to the transmitter.