Short-range radio device specialists Low Power Radio Solutions (LPRS) has developed an unusual application using wireless technology that means clay pigeon shooting can be enjoyed without firing lead shot around the countryside. The application is being used by leisure pursuits company Lasersport International.

The Lasersport guns are de-activated 12 bore shotguns which instead of firing lead cartridges direct infrared beams at reflective and re-usable clays. To make the sport more variable for different skill levels the speed and angle at which the clays fly can be adjusted. Each of the guns has its own identity and the scores of each player are shown on an electronic scoreboard.

ENABLING TECHNOLOGY
So what's the technology enabling the system? For this application LPRS used wireless modules from Circuit Design, a manufacturer of low power radio products. The transmitter module used here was the CDP-TX-02E-R which has a typical range of 1Km.

These R&TTE compliant narrowband multi channel radio modules use TCXO (temperature controlled crystal oscillator)m technology and the minimum operating temperature has been expanded from -10C in the earlier models to -20C. Output complies with the European ISM band RF power limit *1, and you can select either 10 mW or 1 mW. In this way the modules can be used in applications where continuous transmission is necessary in all 32 channels.

To maintain reliability and stability in harsh operating conditions, Circuit Design has improved the blocking performance and selectivity of the receiver, to achieve receiver class 1*2 classification as defined in EN300220.

The features of CDP-TX-02E-R/CDP-RX-02E-R include:

1. R&TTE and RoHS compliant radio modules.

2. Class 1 receiver supported by high reliability; Blocking or desensitisation: 84dB (All); Adjacent channel selectivityin band: 60dB (25kHz channel spacing); Adjacent band selectivity: 60dB.

3. Achieves an operating temperature range from -20 to 60C using aTCXO-based temperature compensation circuit.

4. 1mW/10mW RF output selection.

5. A transmission circuit structure that is highly resistant to reflection.

6. 25kHz step 32 multi channels.

7. Improved shock and vibration resistance.

8. Uses a custom SAW filter to avoid radio interference from other radio equipment.

9. High receiver sensitivity using double superheterodyne receiver circuits: -120dBm (12dB SINAD/BER 1percent).

Supplier of the modules Circuit Design is based in Nagano, Japan.

See associated figure