Abstract: A data system and method for entering, storing and displaying a desired digital time which replaces a conventional input keyboard, rotary switch, or thumbwheel switch for a digital timer or clock. This system processes the voltage from a manually positioned wiper of a potentiometer through an inexpensive analog-to-digital converter, displays the digital data to the operator for identification, and holds the data for further processing. The operator repositions the wiper so as to sequentially display a digital time in response to a static or steady state digital signal until the desired digital time is displayed.

Abstract: An electronic triggering circuit is disclosed for developing a periodic control signal having a variable duty cycle. The periodic control signal is developed in synchronization with an applied alternating line voltage and is utilized for rendering a semiconductor switch conductive and nonconductive in timed relationship to the negative half cycle of the applied line voltage. The semiconductor switch is interposed between the line voltage and a load, which may be the power supply for a microwave oven, such that as the duty cycle of the control signal is varied the microwave power supplied to the oven is also varied. By rendering the semiconductor switch operative in timed relationship to the line voltage transients are minimized therethrough.

Abstract: Two AC-DC regulator circuits are disclosed which are suitable for providing a constant minimal ripple DC supply voltage in response to AC line voltages having varying peak amplitudes. Each of the regulator circuits includes a sensing and a trigger pulse circuit which operates in cooperation with a current control circuit to maintain a predetermined constant DC load supply voltage. Moreover, undesirable transient trigger signals, due to initiation or termination of the AC line voltage, are discriminated against providing circuit protection to the applicable load to be used. The regulator circuits are suitable for operation in environments that may be encountered in worldwide applications, i.e., power distributions that may vary from 90 upwards to 250 volts with frequencies of 50 hertz to 60 hertz.