PROTECTION DEVICE FOR RADIO ELECTRON UNIT Russian patent published in 1999 - IPC

FIELD: radio electronics. SUBSTANCE: proposed device is designed for protection of radio electron units against short-time overvoltages in alternating current power supply network. It has two voltage limiters 5, 6 connected in series and in opposition one to another and linked between conductors feeding supply voltage to radio electron unit. Specific feature of device is that first resistor 10 and first light guide 8 are connected in series and form first network, second resistor 11 and light guide 9 form second network. Both networks are connected in series and linked to conductors feeding supply voltage to radio electron unit. First and second light guides are connected in opposition. Points of connection of networks and voltage limiters are connected via third light guide 12. During positive half-period of network voltage limiter 5 conducts current, limiter 6 is shut, light guide 12 glows but light guide 9 will not glow though current of inverse polarity limited by high-resistance resistor 11 will flow through it as through diode. In case of short-time pulse of overvoltage light guide 12 alone will glow. If damage threshold of voltage limiter 5 or 6 is achieved either light guide 8 or light guide 9 will glow. If both light guide 8 and 9 glow and light guide 12 does not glow it shows that both voltage limiters 5 and 6 have failed. Invention makes it possible to provide for indication of failure of overvoltage limiters 5, 6 which enhances operational reliability of radio electron unit. Device also indicates presence of absence of network voltage. EFFECT: enhanced operational reliability of radio electron unit. 1 dwg