UHF FM Data Receiver

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433.92 MHz FM Data Receiver

The low and high pulses are encoded with frequency shift keying. The receiver can only decode a pulse stream.

A possibly student-proof module.

D1 is a polarity protection diode.
R1 limits the current to about 15mA. About half this current flows through the Zener diode and the rest is taken by the receiver module.
ZD is the 5.1 Volt Zener diode used to provide a stable 5 volt supply for the receiver.
R2 limits the transistor base current to about 50µA
The diode in series with R2 is used to drop 0.7 volts ensuring the transistor turns off properly.
The transistor (BC182L) acts as a switch. When on, it pulls the output voltage down to about 0.2V
R3 is a pull-up resistor. This holds the output voltage high while the transistor is off.