| 摘要 |
<p>The combined signal transmitter (12) and signal receiver (10) are for controlled access provision to data and communication channels (1,2,3). The transmitter and receiver are arranged for the transmission and receipt of an infrared or radio signal and on receipt of the signal to provide access to the data and/or communication channels. The signal transmitter is a disposable product and transmits a predetermined signal once during a predetermined time. The transmitter incorporates a voltage source, a contact switch and a programmable integrated circuit, in which the signal to be transmitted is stored and the time at which the signal is to be transmitted.</p> |
