RF transmitter receiver



The TWS-434 and RWS-434 are extremely small, and are excellent for applications requiring short-range RF remote controls.  The transmitter module is only 1/3 the size of a standard postage stamp, and can easily be placed inside a small plastic enclosure.
TWS-434:  The transmitter output is up to 8mW at 433.92MHz with a range of approximately 400 foot (open area) outdoors.  Indoors, the range is approximately 200 foot, and will go through most walls.....

TWS-434A
The TWS-434 transmitter accepts digital inputs, can operate from 1.5 to 12 Volts-DC, and makes building a miniature hand-held RF transmitter very easy.  The TWS-434 is approximately the size of a standard postage stamp.

TWS-434 Pin Diagram

Sample Transmitter Application Circuit
RWS-434:  The receiver also operates at 433.92MHz, and has a sensitivity of 3uV.  The RWS-434 receiver operates from 4.5 to 5.5 volts-DC, and has both linear and digital outputs.
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RWS-434 Receiver

RWS-434 Pin Diagram
Note: For maximum range, the recommended antenna should be approximately 35cm long.  To convert from centimeters to inches -- multiply by 0.3937.  For 35cm, the length in inches will be approximately 35cm x 0.3937 = 13.7795 inches long.  We tested these modules using a 14", solid, 24 gauge hobby type wire, and reached a range of over 400 foot.  Your results may vary depending on your surroundings.

Sample Receiver Application Circuit
The example above shows the receiver section using the HT-12D decoder IC for a 4-bit RF remote control system.  The transmitter and receiver can also use the Holtek 8-bit HT-640/HT-648L remote control encoder/decoder combination for an 8-bit RF remote control system.  Here are the schematics for an 8-bit RF remote control system:
Click HERE to download the RWS & TWS datasheet in Adobe PDF format.
Driving Relays:
Using the outputs of the HT-12D or HT-648L decoder ICs to drive relays is quite simple.  Here are schematics showing how to drive relays directly from the data-output pins of the decoder.

NPN Relay Driver Circuit

PNP Relay Driver Circuit