CN215580376U - Novel circuit for preventing short circuit and current backflow - Google Patents

Abstract

The utility model is suitable for the technical improvement field of electronic circuits, and provides a novel short-circuit-proof and current-backflow-proof circuit which comprises a power module, a switch module, a voltage stabilizing module, a recovery module and an output module, wherein the output end of the power module is connected with the input end of the switch module, the output end of the switch module is connected with the input end of the voltage stabilizing module and the input end of the recovery module, and the output end of the recovery module is connected with the input end of the output module. The circuit has the advantages of simple structure, convenient use, effective protection of the power supply, reduced damage and reduced cost.

Description

Novel circuit for preventing short circuit and current backflow

Technical Field

The utility model belongs to the technical improvement field of electronic circuits, and particularly relates to a novel short-circuit-proof and current-backflow-proof circuit.

Background

When there is an interface that needs to output voltage externally to supply power to an external device, a voltage port needs to be provided externally. For example, the external device needs to use 5V voltage, and at present, there are two general circuit design ways, one is to directly lead the 5V power supply inside the device to the outside to supply power to the external device. As shown in fig. 1. This is the least expensive, the simplest and the simplest way, but the greatest risk is encountered.

When static electricity exists in the external equipment or the external line, or a high-voltage power supply is introduced into the 5V line for other reasons, the 5V power supply of the host and the external equipment can be damaged.

In order to prevent the damage of the host power supply caused by the externally introduced high-voltage power supply, an improved circuit is provided. As shown in fig. 2.

Utilize the one-way conducting's of diode characteristic, when toouter output 5V power, insert a diode to the external power of 5V of host computer can only be from inside output to the outside, when external voltage is greater than inside 5V voltage, the diode ends, thereby has prevented inside that outside high pressure introduces the host computer, has protected the host computer.

However, the above two solutions have no solution to the other problem:

when the 5V line is output externally, the 5V circuit and the GND circuit are short-circuited due to external reasons. Once short-circuited, the current will increase sharply, and the power supply inside the host will be damaged.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a novel short-circuit-preventing and current-backflow-preventing circuit, which aims to solve the technical problem of internal power supply damage caused by short circuit of an external circuit.

The utility model is realized in such a way that the novel short-circuit-proof and current-backflow-proof circuit comprises a power module, a switch module, a voltage stabilizing module, a recovery module and an output module, wherein the output end of the power module is connected with the input end of the switch module, the output end of the switch module is connected with the input end of the voltage stabilizing module and the input end of the recovery module, and the output end of the recovery module is connected with the input end of the output module.

The further technical scheme of the utility model is as follows: the recovery module adopts a self-recovery fuse tube F30, and one end of the self-recovery fuse tube F30 is connected with the output module.

The further technical scheme of the utility model is as follows: the voltage stabilizing module comprises a diode D114 and a capacitor C338, wherein the cathode of the diode D114 and one end of the capacitor C338 are respectively connected with the other end of the self-recovery fuse F30, and the anode of the diode D114 and the other end of the capacitor C338 are respectively grounded.

The further technical scheme of the utility model is as follows: the switch module comprises a diode D113, the cathode of the diode D113 is respectively connected with the cathode of the diode D114, one end of a capacitor C338 and the other end of a self-recovery fuse F30, and the other end of the diode D113 is connected with the output +5V of the power supply module.

The further technical scheme of the utility model is as follows: the self-recovery fuse F30 is of a type 500mA/0476.500 NR.

The utility model has the beneficial effects that: the circuit is simple in structure and convenient to use, effectively protects the power supply, reduces damage, reduces circuit loss and reduces cost. By adding the self-recovery fuse, the service life is effectively prolonged, the safety of the circuit and the service life of devices are guaranteed, and the self-recovery fuse can be widely applied to the technical field of electronic circuits.

Drawings

Fig. 1 is a block diagram of a prior art circuit configuration.

Fig. 2 is a block diagram of a circuit configuration of the prior art.

Fig. 3 is a block diagram of a novel short-circuit prevention and current backflow prevention circuit provided by the embodiment of the utility model.

Fig. 4 is an electrical schematic diagram of the novel short-circuit prevention and current backflow prevention circuit provided by the embodiment of the utility model.

Detailed Description

As shown in fig. 3 to 4, the novel short-circuit-prevention current backflow-prevention circuit provided by the present invention includes a power module, a switch module, a voltage stabilization module, a recovery module, and an output module, wherein an output end of the power module is connected to an input end of the switch module, an output end of the switch module is connected to an input end of the voltage stabilization module and an input end of the recovery module, and an output end of the recovery module is connected to an input end of the output module.

The recovery module adopts a self-recovery fuse tube F30, and one end of the self-recovery fuse tube F30 is connected with the output module.

The voltage stabilizing module comprises a diode D114 and a capacitor C338, wherein the cathode of the diode D114 and one end of the capacitor C338 are respectively connected with the other end of the self-recovery fuse F30, and the anode of the diode D114 and the other end of the capacitor C338 are respectively grounded.

The switch module comprises a diode D113, the cathode of the diode D113 is respectively connected with the cathode of the diode D114, one end of a capacitor C338 and the other end of a self-recovery fuse F30, and the other end of the diode D113 is connected with the output +5V of the power supply module.

The self-recovery fuse F30 is of a type 500mA/0476.500 NR.

The solution of adding diodes, which prevents the introduction of external high voltage to the internal power supply, is continuously used. But the situation that the internal power supply is damaged when an external circuit is short-circuited cannot be solved.

A diode is introduced into an externally output power supply, and a self-recovery protective tube is additionally arranged at the cathode of the diode.

Thus, when the external 5V short circuit occurs, the current flows out of the anode of the host, flows through the diode, passes through the self-recovery fuse and finally reaches the external circuit. After the short circuit, the current increases rapidly, and when the current increases, the self-recovery fuse tube generates heat, thereby breaking the circuit and cutting off the output of the current.

After the current is cut off, no current passes through the self-recovery fuse tube, so that the temperature can drop, and after the temperature drops, the self-recovery fuse tube can recover the conduction state. The circuit continues to supply power to the outside. Because the external circuit is broken, the above is continued again: current increase, temperature rise, self-recovery fuse disconnection, temperature drop, conduction … …

In order to prevent the diode from breaking down due to overlarge voltage, a voltage stabilizing diode is also introduced between the diode and the self-recovery fuse, and after the voltage exceeds the rated voltage of the voltage stabilizing diode, the voltage stabilizing diode is conducted, so that a large amount of current is introduced into 0V, the self-recovery fuse tube is accelerated to generate heat, and the circuit is cut off.

And a self-recovery protective tube is added to the cathode of the diode. Meanwhile, a voltage stabilizing diode is additionally arranged between the diode and the self-recovery protective tube, and when the external induced voltage is overlarge, the voltage stabilizing diode is conducted, so that the one-way diode is prevented from being broken down by large voltage.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (5)

1. The utility model provides a novel prevent short circuit and prevent circuit of electric current backward flow which characterized in that: the novel circuit for preventing short circuit and current backflow comprises a power module, a switch module, a voltage stabilizing module, a recovery module and an output module, wherein the output end of the power module is connected with the input end of the switch module, the output end of the switch module is connected with the input end of the voltage stabilizing module and the input end of the recovery module, and the output end of the recovery module is connected with the input end of the output module.

2. The novel circuit for preventing short circuit and current backflow as claimed in claim 1, wherein the recovery module employs a self-recovery fuse F30, and one end of the self-recovery fuse F30 is connected to the output module.

3. The novel circuit for preventing short circuit and current backflow as claimed in claim 2, wherein the voltage stabilizing module comprises a capacitor C338 in the class of diode D114, the cathode of the diode D114 and one end of the capacitor C338 are respectively connected to the other end of the self-recovery fuse F30, and the anode of the diode D114 and the other end of the capacitor C338 are respectively connected to ground.

4. The novel circuit for preventing short circuit and current backflow as claimed in claim 3, wherein the switch module comprises a diode D113, a cathode of the diode D113 is connected to a cathode of the diode D114, one end of a capacitor C338 and the other end of a self-recovery fuse F30, respectively, and the other end of the diode D113 is connected to +5V output of the power module.

5. The novel circuit for preventing short circuit and current backflow as claimed in claim 4, wherein the self-recovery fuse F30 is of the type 500mA/0476.500 NR.

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