UNIVERSAL DC SENSOR WITH UNCOUPLING AND LOW-VOLTAGE POWER SUPPLY Russian patent published in 2015 - IPC G01R19/00 

FIELD: measurement equipment.

SUBSTANCE: sensor comprises a measurement shunt, connected in series with a load, an operational amplifier (OA), a transformer, four interchanged switching links, an integrator, a control transistor of p-n-p type. The first output of the shunt is connected to the second output of the load. The second output of the shunt is connected to the switching contact of the second link. The first output of the load is connected to the switching contact of the first link. Normally open contacts of the first and fourth link are connected with a normally closed contact of the second link and a plus bus. The base of the transistor via the resistor is connected to the outlet of the OA and via the other resistor with the emitter of the transistor, and the emitter is connected to the plus output of the OA power supply and the plus bus. The minus output of the OA power supply is connected with the common bus. The collector of the transistor is connected to the inlet of the RC-filter, the outlet of which is connected to the buses of power supply of the introduced blocking generator, assembled with usage of the transistor, two resistors, a capacitor, a diode and two windings of the transformer. Two other windings with identical transformation ratios are connected to the introduced voltage multipliers. The outlet of the first multiplier is connected to the device outlet. The positive outlet of the second multiplier via the feedback resistor is connected to a non-inverting inlet of the OA, and the negative one - to an inverting inlet of the OA. The first divider is connected between the plus bus and the switching contact of the third link, and its outlet is connected to the inverting inlet of the OA. The second divider is connected between the switching contact of the fourth link and the common bus, and its outlet is connected to the non-inverting inlet of the OA. The balancing resistor with taps, which is connected to the balancing outputs of the OA. The fifth interchanged link is connected between the plus bus and one of the outlets of the balancing resistor.

EFFECT: simplification and increased reliability of a device.

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