Carrier-Current Transmitter for Data Transmission
Created: Jan 05, 2015
No description available.
In this circuit, data at input C is amplified by U2 and then fed to modulator U1. U1 generates two frequencies, depending on the values of C5, R10, R3, R11, and R6. The frequency f1 is generated if pin 9 of U1 is LOW and f2 if pin pin 9 of U1 is HIGH. A square wave appears at pin 13 of U1 and is fed to Q1, an amplifier stage, that is coupled via tuned transformer T1 to the ac line via C1 and C2. Notice that, for safety reasons, C1 and C2 must be specifically rated for the ac line voltage.