Low-voltage DC load overload measurement and control circuit

Abstract

The invention relates to an overload measurement and control circuit for a low-voltage direct current load. The overload measurement and control circuit for the low-voltage direct current load comprises a driver DR, a direct current load DL, a thyristor VT1, an MOS tube VT2, a voltage stabilizer tube DW1, a voltage limiting tube DW2, a comparator IC1, an inductor L1, a diode D1, a power source light LED1, an output lamp LED2, a voltage stabilizer resistor R1, an anode resistor R2, a grid resistor R3, an output resistor R4, a gate resistor R5, a voltage stabilizer capacitor C1, a filter capacitor C2, a setting capacitor C3 and the like. According to the overload measurement and control circuit for the low-voltage direct current load, a power field-effect tube with ultralow on-resistance is utilized as a current detecting element and a circuit turn-off control element, the semi-control characteristic of the thyristor, the trace inductor connected in a load circuit and a quick judging circuit are combined, and real-time detection, judgment and safety control over the overload and short-circuit faults of the low-voltage direct current load are achieved. The overload measurement and control circuit for the low-voltage direct current load is simple in structure, safe, reliable and low in cost.

Description

technical field [0001] The invention belongs to the field of industrial measurement and control, and relates to a circuit, in particular to a low-voltage DC load overload measurement and control circuit, which is suitable for occasions requiring real-time detection and safety protection control of overload or short-circuit faults of low-voltage DC loads. Background technique [0002] When using a DC drive power supply (also called a driver) to supply power to a low-voltage DC load, it often occurs that the DC drive power supply and the load itself are damaged due to load overload or short circuit. Therefore, real-time detection and safety of overload and short circuit faults must be carried out. protection control. At present, the commonly used effective method is to detect and compare the load current in real time through the Hall current sensor with rapid response, and issue an instruction when it exceeds the safety threshold, shut down the driver and issue an alarm indica...

AI Technical Summary

Problems solved by technology

The problems of this method are: first, the current is very large due to load overload or short-circuit fault, so the capacity of the power device in the driver should be taken with a large margin, and the range of the Hall current sensor used for short-circuit detection should also be selected. The normal working current is relatively large, which makes the cost very high; second, for the short-circuit fault that occurs instantaneously, it is often too late to protect the internal power device of the driver.

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