Features
Range over 200m (tested using Jaycar UHF modules)
Receiver has momentary or toggle output
Adjustable momentary period
Receiver can drive a 12V relay
Transmitter draws no standby current from 9V battery
Transmit and receive indication
Up to five receivers can be used in the same vicinity
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SECURITY NOTE
While this UHF Remote Switch has protection against unauthorised access via its "identity" settings, there is little to prevent someone with a similar transmitter stepping through these identities if the basic operation is known.
Therefore it should not be placed in locations where security could be compromised
- eg, used on a garage door opener where the
garage gives access to the rest of the home.
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A cheap garage door controller is just one use for our
UHF Remote Switch. If your brand-name garage door remote control is broken or lost, you’ll be able to build this whole project - transmitter AND receiver – for much less than the cost of replacing the original remote!
There are quite a few 433MHz transmitter and receiver modules around these days. Relatively inexpensive, they are ideal for remote control applications as well as their more usual tasks, wireless data links. While the majority offer only fairly short range (tens of metres), some can work over a 200m+ range.
Even tens of metres range is a considerable improvement over infrared transmitter and receiver pairs that not only have limited range (<10m) and usually don’t work well in sunlight but more importantly, have strictly line-of-sight reception. A wall, a filing cabinet, even a vase of flowers can stop infrared dead – just like your TV/video infrared remote control.
On the other hand, UHF modules can operate where there is no line-of-sight between the transmitter and receiver. They’ll even work through (most!) walls, although walls with interior aluminised insulation or similar will cause them grief.
Commonly known as 433MHz data transceivers, they operate on the 433.050MHz to 434.790MHz band, at a level of 25mW. Classified as Low Interference Potential Devices (LIPD), they are widely used for sending wireless data in industrial, medical and for scientific purposes.
However, these days you are more likely to find them in wireless consumer applications such as door openers, doorbells and weather stations.
We have used these devices in the past for various wireless applications, including the Water Tank Level Meter featured in SILICON CHIP between November 2007 and January 2008.
