The present invention also relates to the processing of the signal at the microphone (36) by means of an N-path filter comprised of a cyclic switch (63) and RC circuits (62, 65, 65').

In response to the signals the switch (23) is cyclically operated.

The apparatus (40, 122) eliminates premature switch failure, inadvertent cyclical switch actuation and electrical wire breakage.

The switch controller is configured to cyclically linearly vary the duty cycle of the output signal at the switch output.

As a result of these steps, the energy dissipation in the resistor (135) is dependent on the duty cycle of the switching element (11).

The controller (60) then controls the switch such that the decided duty ratio is realized.

The controller may include a voltage mode or current mode duty ratio controller that controls a duty ratio of a switch of the ballast.

The switch (100) also has a cycling arm (112) for adjusting the time duration that the cycling contacts (115, 116) are opened and closed.

The bidirectional current can be established by means of a single current switch TR1 which is operated cyclically.

A new switch position takes effect only after the CIM is power-cycled.

The signal with a small duty cycle is output to a switch (330, 123) and controls the switch (330, 123) to switch on and off periodically.

The DC/DC converter (32), which has at least a switch (40), converts, in accordance with a variable duty ratio of the switch, a power supplied from a solar battery (12) to a capacitor (14).

Apparatus (40, 122) for actuating an electrical switch (42, 124) which eliminates the problems of over stressing and inadvertent cyclical actuation of the switch (42, 124) and flexing of electrical connecting wires (66, 168).

The sub-stages (21, 22) are connected to the output of the sampler (2) in a successive and cyclic way by and use of a switch (23).

This negative compensation may be provided only when the duty cycle of the switch control signal is less than a threshold, such as 50%.