Detection circuit for overcurrent of alternating current and direct current

Abstract

The invention discloses a detection circuit for overcurrent of alternating current and direct current. The detection circuit is composed of a first photoelectric coupler (U1), a second photoelectric coupler (U2), a sampling resistor (R1), a current-limiting resistor (R2), a pull-up resistor (R3), system input 1 (IN1), system input 2 (IN2) and system output (OUT), wherein the sampling resistor (R1) is used for measuring the current, the sampling resistor (R1) and the current-limiting resistor (R2) set the overcurrent detection threshold, the first photoelectric coupler (U1), the second photoelectric coupler (U2) and the pull-up resistor (R3) perform signal transformation, and overcurrent signals are output. The detection current is simple in structure, is low in cost, is suitable for the overcurrent detection of the alternating current and the direct current and can be used for the overcurrent detection of high potential at the same time.

Description

technical field [0001] The invention belongs to the technical field of detection, and in particular relates to an AC and DC overcurrent detection circuit, which is applicable to overcurrent detection in AC circuits and DC circuits, and can be used for high potential overcurrent detection. Background technique [0002] All electronic equipment or products have a rated current, and it is not allowed to exceed the rated current, otherwise the service life of electronic devices will be greatly reduced, and even the equipment will be burned. This requires a current protection module. When the current exceeds the set current, an over-current signal is given, and the device can automatically power off according to the over-current signal to protect the device. There are many kinds of existing over-current detection circuits, most of which are complex in structure; the complexity of the circuit directly leads to the increase of cost, and the over-complexity of the circuit also leads...

AI Technical Summary

Problems solved by technology

There are many kinds of existing over-current detection circuits, most of which are complex in structure; the complexity of the circuit directly leads to the increase of cost, and the over-complexity of the circuit also leads to the increase of unstable factors and reduces the stability of the circuit; and the existing over-current detection circuit is rarely There are circuits that can detect AC and DC at the same time; in some special applications, such as when the overcurrent detection is required not to affect the ground potential, the overcurrent detection circuit must be placed at a higher potential position in the circuit. The overcurrent detection circuit does not have the function of high potential overcurrent detection

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