Remote Control using RF (transmitter)

These days, transmit- and receive modules that operate on the well-known 433-MHz licence-free frequency are reasonably cheap and freely available at electronics stores. The circuit described here makes use of the transmitter/receiver combination available from Conrad Electronics, which stands out because of its low price. A disadvantage with this setup is the available bandwidth. At 2 kHz this is quite limited, but still sufficient for our purpose. We assume that the RC5 remote control system from Philips is being used.

Resistors:

R1 = 100

R2 = 4k7

Capacitors:

C1, C3 = 100µF 10V radial

C2 = 100nF ceramic

Inductors:

L1 = 10µH

Semiconductors:

D1 = zener diode 5V1 0.5W

T1 = BC547B

IC1 = SFH5110-36

Miscellaneous:

S1 = miniature slide switch SX254 (Hartmann) (Conrad Electronics # 708062) or 3-way pinheader with jumper

MOD1 = 433.92 MHz AM transmitter module from Conrad Electronics set, # 130428

PCB, ref. 054013-1