Abstract: A DC power source light which is mountable to and dismountable from a camera body of a video camera is supplied with power from a battery provided in said camera body so that said DC power source light is made compact and light in weight. Further, either said camera body or said DC power source light has a unit for preventing excess discharge of said battery and a unit for preventing excess current when the switch is turned on, thereby to protect said battery.

Abstract: A detector circuit for detecting a phase or frequency error of an input signal. One mode of at least two detection modes is selected according to a phase or a frequency of the input signal with each mode having a reference value of a phase or a frequency of the input signal and reference values of the detection modes being different from each other. A pulse signal having a phase corresponding to a difference between an actual phase or frequency of the input signal and the reference value of the phase or the frequency is generated, and a predetermined carrier signal is pulse width modulated with a predetermined modulation factor in response to the pulse signal, the modulation factor being different for each detection mode.

Abstract: A programmed timer for presetting a video tape recorder for the time and reception channel when the video tape recorder starts and ends, comprising a processor circuit for processing the type of the data entered for reservation in a predetermined order, and means for sequentially displaying a procedure to be next entered each time data are entered. The operator is required to enter the necessary data simply according to the displayed procedure in order to set the desired reservation data for the programmed timer.

Abstract: A relay control circuit is disclosed in which a timer circuit is actuated by a reference clock pulse in synchronism with an AC voltage supplied by a commercial power supply. An output signal of the timer circuit causes current to flow in the coil of the relay thereby to close the contact of a relay. The invention further comprises a polarity-reversing device for reversing the polarity in accordance with the variations in the output signal of the timer circuit. The reference clock pulse is applied to the timer circuit through the polarity-reversing device.

Abstract: An automatic control apparatus for protecting the compressor motor used with the refrigeration system of an air conditioning unit. The control apparatus has a timer for prohibiting the restart of the compressor motor until the lapse of a predetermined time after temporary stoppage of the compressor motor, and a holding circuit for holding a power source voltage for a predetermined period of time while the operation of the air conditioning unit is stopped. Even if the power supply is turned off, therefore, the source voltage supplied by the holding circuit enables the timer circuit to continue its operation for a predetermined length of time.