Series-connection current limiting circuit of miner lamp intrinsic safety power supply

Abstract

The invention discloses a series-connection current limiting circuit of a miner lamp intrinsic safety power supply. The series-connection current limiting circuit of the miner lamp intrinsic safety power supply is characterized by comprising a DC / DC (Direct Current / Direct Current) boosted circuit, a control circuit, a reference power supply, a current sampling circuit, a voltage sampling circuit and a three-stage series-connection power adjusting and protecting circuit, wherein the DC / DC boosted circuit is formed by an IC1 (Integrated Circuit), diodes, capacitors and a resistor and is used for supplying a control power supply; the control circuit is formed by an IC2 and resistors and used for setting and comparing the voltage and the current; the reference power supply is formed by an IC3, a resistor and a capacitor and is used for supplying the preset control voltage for a '+' input end of the IC2; the current sampling circuit is formed by a resistor R1 and a resistor R2, and the voltage sampling circuit is formed by a resistor R12 and a resistor R13, and the current sampling circuit and the voltage sampling circuit are respectively used for supplying the preset control voltage for a '-' input end of the IC2; and the three-stage series-connection power adjusting and protecting circuit is formed by an FET2 (Field Effect Transistor), an FET3 and an FET4. According to the series-connection current limiting circuit of the miner lamp intrinsic safety power supply, disclosed by the invention, the current limiting circuit is formed by applying power semiconductor devices and other electronic devices, and the situations that when in normal work, the inner resistances of the devices are kept to the lowest, and no influence on the working performance of loads is realized; and the inner resistances of the devices can be increased immediately when the loads are in over current or short circuit failure, the failure current can be immediately limited within the safety current, and thus the miner lamp power supply can be safely protected.

Description

1. Technical field [0001] The invention belongs to the special safety technology for miner's lamps, and in particular relates to a series current-limiting circuit for safety protection of the miner's lamp power supply. 2. Background technology [0002] At present, my country's miner's lamp uses a miner's lamp protector to protect the miner's lamp from short-circuit or over-current faults during use. Cut off the fault current, and the protection effect is outstanding; when the battery is discharged to the second half, the internal resistance of the power circuit is large, the fault current is small, or the fault short-circuit point is falsely connected, the protection effect is limited, or even cannot play a protective effect. How to eliminate safety hazards, limit the fault current below the safe current, and make the miner's lamp power supply meet the intrinsically safe standard is an important issue in the miner's lamp design. Intrinsically safe miner's lamp is designed to...

AI Technical Summary

Problems solved by technology

At present, there are no intrinsically safe miner's lamps in China, which are in a blank state; there are intrinsically safe miner's lamps abroad, according to the information and samples that can be found at present, the current limiting methods of foreign intrinsically safe miner's lamps all use series reliable resistors, that is, If the value of the current limiting resistor is selected to be small, the fault current of the loop is still very large, and the current limiting effect cannot be achieved; if the value of the current limiting resistor is selected to be large, the voltage drop across the current limiting resistor is large, and it will directly It affects the working time of the light source. In order to solve the problem of voltage drop in the resistor, it is necessary to increase the capacity of the battery to make up for the existing problem. In this way, there are problems such as the large size of the miner's lamp and the high cost of the battery.

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