Using the Circuit Specialists RXD4140-434 RF Modules

The RXD4140-434 (4Ch RF Remote Control System featuring KeeLoq Code Hopping) unit available from Circuit Specialists is a powerful, easy to use RF System that can add remote control capabilities to essentially any electrical/electronic device. The unit comes with two transmitting FOBs (similar to those used on remotes for automobiles and alarms) and one receiver board. Since the transmitter units are self-contained and require no additional circuitry, they will not be addressed in this article. The receiver unit however requires external components and connections for operation. The attached circuit shows all parts and connections required to make a Four channel remote control system that will toggle ON and OFF the four relays. Each time the corresponding key on the transmitter is pressed, the associated relay will toggle states (ie. from OFF to ON or from ON to OFF).

A representative schematic diagram is attached. The +5 Volt power and ground connections to the D Flip Flop IC’s (CD4013) are not shown for simplicity but must be connected for operation. The parts list for the representative circuit is as follows:

QTY                     Description                              Part Number

1                           RF Module                                RXD4140-434

2                           Dual D Flip-Flop                       CD4013

2                           LED                                            L934HD

1                           PB Switch                                  R18-29A Red

4                           Silicon Diode                            1N4001

4                           5 Volt Relay SPDT                     R56-1D.5-6D

4                           Resistor 1/4 Watt 1.0K             RA1.0K



George Leger has a Masters in Electrical Engineering from Stanford University, worked in private industry pioneering surface-mount technology and in government research labs for twenty years, published several papers on surface-mount technology, co-authored papers published in national symposiums on accelerator technology, was past president of SMTA and an adjunct professor at the community college level, holds a patent, and is a certified microchip design partner, serving as a consultant to many companies developing electronic circuits.

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