THREE-LEVEL VOLTAGE INDICATING DEVICE Russian patent published in 2007 - IPC G01R19/165 B23K9/00 

FIELD: the invention refers to electrical devices.

SUBSTANCE: the arrangement has an input clamp for connecting a controlled source and a feeding clamp. It also has a single half-wave voltage rectifier consisting of a diode and a condenser connected to a resistive voltage divider. The output of the last is connected through the first resistor to a noninverting input of an operating amplifier. The inverting input of the operating amplifier is connected with the output of a supply voltage divider. The supply voltage divider consists of in-series connected the second and the third resistor. Through the fourth resistor it is connected with the output of the operating amplifier and the emitter of a key transistor whose base is connected with the inverting input of the operating amplifier and the collector is connected through the second condenser with the noninverting input of the operating amplifier. The supply voltage divider is connected through the fifth resistor with the common conductor. The output of the operating amplifier is connected through a limiting resistor and a light diode to the common conductor. The collector of the key transistor is connected to a main-electrical breaker of the supply of the controlled source of voltage. The output of the resistive voltage is connected through the second diode with a temperature sensor of the power device of the source of voltage of the controlled arrangement. The output of the operating amplifier may be connected with the electrode of a piezoelectric acoustic transmitter, whose second electrode is connected with the common conductor. The technical result is simplification of scheme realization and improvement of exploitation of the controlled arrangement due to indication of changing of the voltage level of the supply circuit from the minimum value to maximum in the limits of admissible norm with following blinking of the light diode at going out beyond the limits of the standard mode of functioning.

EFFECT: simplification of the scheme of the arrangement.

2 cl, 2 dwg