Here we explain a couple RF 433kHz remote control chips especially designed for the purpose. The IC TWS-434 along with its encoder chip HOLTEK’s HT-12E form a high class transmitter circuit, whereas the chip RWS-434 through its complementing decoder IC HT-12D operates as the receiver module. Both of the above modules are able to exchange 4-bits of discrete data for control four external loads separately.
With the easy availability of accurate remote control chips, making your own universal remote control modules is today just a matter of few hours. We discuss a couple of compact RF remote control transmitter and receiver modules here using the chips: HT-12E, HT-12D, TWS-434, RWS-434
Making a hi-end professional remote control system at home is a child’s play now. With the advent of micro remote control encoder and decoders chips, making a RF remote control is today a matter of a few hours or rather minutes. Applications of remote controls made from these chips are countless; you may use it for controlling practically any electrical gadget that you can think of, the best application being for car security systems.
A couple of RF remote control chips, the TWS-434 and the RWS-434 both complement each other, the first one being the transmitter and the later one the receiver.
The chip TWS-434 is basically a tiny 4-bit transmitter module, which is able to transmit 4 types of coded signals discretely, whereas the RWS-434 exactly compliments these signals by receiving them and generating 4 discrete decoded signals at its outputs.
However both the above primarily functions just as wireless sender and receiver and therefore require external encoders and decoders to be integrated for the said operations.
Understanding the Transmitter Module
A couple of HOLTEK’s encoder and decoder chips HT-12E and HT-12D work in conjunction with TWS-434 and RWS-434 respectively to produce the desired ideal universal remote control operating parameters.
Referring to the diagram alongside, we find a straightforward RF transmitter configuration using the chip TWS-434 and HT-12E.
The IC TWS-434 has in all 6 pin outs, 1 and 2 are the positive inputs, 3 and 4 are to be grounded, 6 receives the 4-bit encoded signals, pin 5 being the antenna for radiating the received signals.
The 4-bit encoding is done by the IC HT-12E. The wiring of this IC is also very simple; all its 1 to 9 pin-outs are shorted together to ground.
Pin 16 and 15 are coupled to each other through a 750 K resistor.
Pin-outs 10, 11, 12, 13, all receive 4 discrete data simply through the connections of the respective pins to ground via a push button switch.
Pin 14 confirms switching of the transmitter signals when connected to ground via another push button.
Pin 17 is the output and conveys the processed 4-bit ata to the IC TWS-434 for the final relay. Pin 18 is for the positive supply input.
Understanding the Receiver Module
The diagram alongside shows a similar configuration to the above, but with exactly the opposite transits.
Here, the chip RWS-434,s antenna receive the data transmitted by the above transmitter module and sends it to the IC HT-12D for the necessary decoding of the 4-bit data which ultimately is decoded and produced at the respective outputs for driving the connected loads.
Understanding the pin-outs of the IC RSW-434 is pretty simple, pin 1, 6 and 7 are all shorted to ground.
Pin 4, 5 go to the positive supply.
Pin 2 outputs the received data to the decoder IC and pin 8 serves as the antenna.
The decoder chip HT-12D has its entire pin from 1 to 9 fixed to the ground potential.
Pin 15 is connected to 16 through a 33 K resistor as per its specs.
Pin 14 receives the information received by RSW-434 and after decoding the processed data is obtained from the pins 10, 11, 12, 13 respectively, which is further fed to the output driving circuit for activating the connected gadgets.
Both the modules of the above universal remote control work satisfactorily through a regulated 5 volt power supply unit.
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