Abstract: A frequency-sensitive switching circuit includes a selectively-operable switch and a sampling circuit for controlling the switch. First and second signals are supplied to the switch. The first signal is also supplied to the sampling circuit, which senses the frequency of a series of pulses therein and compares such sensed pulse frequency with a set frequency. If the sensed pulse frequency is within the band width of the set frequency, the switch passes the first signal to an output terminal. If the sensed pulse frequency falls outside the band width of the set frequency, the switch passes the second signal to the output terminal.

Abstract: An improved device is operatively associated with a rentable television to enable a viewer to select access to rental channels in addition to free channels. To view the rental channels, the viewer need only depress the channel change selector switch for a minimum predetermined time interval. The fact that access to the rental channels has been provided, is visually indicated. In use, the device performs an improved method of affording selective access to the rental channels in addition to the free channels.