US 4,789,790 A · Digital equipment

Abstract

Digital equipment such as an electronic computer comprises a memory unit, an operation unit and a processing unit. In the digital equipment, a short-time service interruption compensation means in compact and simple constitution is installed within a power conversion circuit, and a timer circuit to halt each of the equipment in case of service interruption for a long time is provided as a runaway preventing safety means for the equipment. A power conversion device of the digital equipment is composed of a rectifier circuit which rectifies the commercial power source voltage, a battery as a service interruption compensation means which performs floating charge of the rectifier circuit output and discharges the charged DC power source so as to treat service interruption of the commercial power source, and a DC to DC conversion circuit which converts DC current from the rectifier circuit at normal state or from the battery during service interruption in DC-DC conversion. The timer circuit prevents each part relating to electronic computer function from improper operation due to runaway in case of service interruption longer than the charging capacity of the battery, and transmits a halt instruction to each part if the service interruption time extends beyond a definite time.

Claims7

Dependent claims

Digital equipment comprising a power conversion device wherein a commercial AC power source is converted to a DC power voltage by the power conversion device, and the DC power voltage is used as a power source for operation of the digital equipment, said power conversion device comprising:

a rectifier circuit for rectifying the commercial power source voltage to produce a rectified voltage on an output of the rectifier circuit;
a battery connected across the output of the rectifier circuit as a short-time service interruption compensation means for being charged by rectified current from the rectifier circuit and for supplying DC voltage based on the charging so as to overcome short-time interruption of the commercial AC power source;
and
a DC to DC conversion circuit connected across the output of the rectifier circuit and across the battery for converting DC current from the rectifier circuit or from the battery into the DC power voltage used as the power source for operation of the digital equipment;
said digital equipment further comprising a timer circuit connected to the commercial AC power source for halting operation of at least part of the digital equipment based on detecting continuing interruption of the commercial AC power source for a predetermined short-time period which is less than a service interruption compensation discharge time of the battery.

2 more elements

Dependencies are inferred from the claim text.

Digital equipment

Life of this patent

Digital equipment

Life of this patent

Abstract

Claims7