Abstract: A novel switching mode power supply (SMPS), which is capable of substantially reducing the response time of the SMPS for generating a plurality of regulated DC output voltages from an AC input power, comprises a first rectifier for rectifying the AC input power to produce a rectified AC power signal within a predetermined range; a transforming device for generating a plurality of scaled-down AC power signals from the rectified AC power signal; a second rectifier for producing and providing a plurality of regulated DC output voltages from the plurality of scaled-down AC power signals to the plurality of loads through respective load lines connected thereto; and a unit for grounding the rectified AC power signal previously charged in the first rectifier if there occurs a disruption in the supply of the AC input power to the SMPS, to thereby promptly produce the plurality of regulated DC output voltages when the supply of the AC input power is resumed.

Abstract: An improved regulator apparatus comprises a regulation unit, in response to an operation signal, for regulating an input voltage to provide a regulated voltage to its dependent load and an overcurrent protection unit for blocking the operation of the regulation unit when a short-circuiting occurs in the load. The overcurrent protection unit includes a bypass transistor for bypassing the operation signal to the regulation unit and a diode for sensing the change in the potential level of the regulated voltage to activate the bypass transistor.

Abstract: A karaoke apparatus evaluates a singer's performance by employing: a microphone for converting the singer's voice into a electrical voice signal; a first analogue to digital (A/D) converter for converting the electrical voice signal into a digitized voice signal; a audiovisual equipment for producing the accompanying music; a second A/D converter for digitizing the accompanying music to produce a digitized accompaniment signal; and a performance evaluator for measuring the difference between the accompanying music and the corresponding karaoke singer's voice to produce a score for the karaoke singer's singing performance.

Abstract: Disclosed herein is an improved VCR power supply capable of selectively breaking a dc supply voltage to an audio apparatus during its audio mute state set by a control unit. The improved power supply comprises a first transistor coupled to an upstream of the audio apparatus for selectively blocking the supply voltage; and a second transistor, in response to an audio mute control signal from the control unit, for controlling the selective breaking operation of the first transistor, thereby achieving a low consumption of electrical energy during the audio mute state.