CN205509479U - Over -discharge protection circuit - Google Patents

Abstract

The utility model discloses an over -discharge protection circuit, put U2, potentiometre RP3, band stop buddhist nun field effect transistor VS and emitting diode LED including resistance R3, electric capacity C1, potentiometre RP2, fortune, it is anodal that battery E is connected respectively to resistance R3 one end, diode D5 is anodal, resistance R4, electric capacity C1 summation potential ware RP2 one end, it is anodal that diode D4 is connected to the resistance R3 other end, diode D5 negative pole is connected respectively to diode D4 negative pole and emitting diode LED is anodal, emitting diode LED negative pole connected load RL, load RL other end connecting band damping field effect transistor VS's the D utmost point, potentiometre RP3 one end is connected respectively to band stop buddhist nun field effect transistor VS's the S utmost point, the potentiometre RP2 other end, the electric capacity C1 other end, diode D6 anodal and battery E negative pole and ground connection. The utility model discloses over -discharge protection circuit adopts fortune to put the U2 cooperation to take damped field effect transistor VS as the controller, and circuit structure is simple, and is with low costs, control deadly from starting to control, and battery E voltage only need change tens of millivolts, and the switching control is fast.

Description

A kind of over-discharge protection circuit

technical field

The utility model relates to a protection circuit, in particular to an over-discharge protection circuit.

Background technique

A device that converts chemical energy into electrical energy is called a chemical battery, generally referred to as a battery. After discharge, the internal active material can be regenerated by charging, and the electrical energy can be stored as chemical energy. When it needs to be discharged, the chemical energy can be converted into electrical energy again. Such batteries are called storage batteries, also known as secondary batteries.

As a power storage device that can be used repeatedly, the battery is widely used. However, the service life of the battery has a great relationship with whether it is often over-discharged. Frequent over-discharge will greatly shorten the life of the battery. The existing Some battery discharge protection circuits use a single-chip microcomputer as the core of detection and control, which has a complex structure and high cost, making it difficult to popularize and apply.

Utility model content

The purpose of this utility model is to provide an over-discharge protection circuit to solve the problems raised in the above-mentioned background technology.

In order to achieve the above object, the utility model provides the following technical solutions:

An over-discharge protection circuit, comprising a resistor R3, a capacitor C1, a potentiometer RP2, an operational amplifier U2, a potentiometer RP3, a damped field effect transistor VS and a light-emitting diode LED. One end of the resistor R3 is respectively connected to the positive pole of the battery E and the diode D5 Positive electrode, resistor R4, capacitor C1 and one end of potentiometer RP2, the other end of resistor R3 is connected to the positive electrode of diode D4, the negative electrode of diode D4 is respectively connected to the negative electrode of diode D5 and the positive electrode of light-emitting diode LED, the negative electrode of light-emitting diode LED is connected to load RL, and the other end of load RL is connected to the belt The D pole of the damping FET VS and the S pole of the damping FET VS are respectively connected to one end of the potentiometer RP3, the other end of the potentiometer RP2, the other end of the capacitor C1, the positive pole of the diode D6 and the negative pole of the battery E and grounded, with a damping field effect The G pole of the tube VS is connected to the slider of the potentiometer RP3, the other end of the potentiometer RP3 is connected to the output terminal of the op amp U2, the same phase end of the op amp U2 is connected to the slider of the potentiometer RP2, and the inverting end of the op amp U2 is connected to the other end of the resistor R4 and the diode D6 negative pole.

As a further solution of the utility model: the diode D6 is a Zener diode.

As a further solution of the utility model: the operational amplifier U2 adopts LM324.

Compared with the prior art, the beneficial effect of the utility model is that the over-discharge protection circuit of the utility model adopts the operational amplifier U2 and the field effect transistor VS with damping as the controller, the circuit structure is simple, the cost is low, the volume is small, and the From control to dead control (completely cut off the load RL circuit), the battery E voltage only needs to change tens of millivolts, and the switching control speed is fast.

Description of drawings

Figure 1 is a circuit diagram of the over-discharge protection circuit.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

Please refer to Fig. 1, in the embodiment of the utility model, an over-discharge protection circuit includes a resistor R3, a capacitor C1, a potentiometer RP2, an operational amplifier U2, a potentiometer RP3, a damped field effect transistor VS and a light-emitting diode LED. One end of the resistor R3 is respectively connected to the positive pole of the battery E, the positive pole of the diode D5, one end of the resistor R4, the capacitor C1 and the potentiometer RP2, the other end of the resistor R3 is connected to the positive pole of the diode D4, and the negative pole of the diode D4 is respectively connected to the negative pole of the diode D5 and the positive pole of the light-emitting diode LED, and the light-emitting diode The negative pole of the LED is connected to the load RL, the other end of the load RL is connected to the D pole of the damping field effect transistor VS, and the S pole of the damping field effect transistor VS is respectively connected to one end of the potentiometer RP3, the other end of the potentiometer RP2, the other end of the capacitor C1, and the diode D6 The positive pole and the negative pole of the battery E are connected to the ground, the G pole with damping FET VS is connected to the slide piece of the potentiometer RP3, the other end of the potentiometer RP3 is connected to the output terminal of the op amp U2, the same phase end of the op amp U2 is connected to the slide piece of the potentiometer RP2, and the op amp The inverting end of U2 is respectively connected to the other end of the resistor R4 and the cathode of the diode D6; the diode D6 is a Zener diode; the operational amplifier U2 is LM324.

The working principle of the utility model is: please refer to Fig. 1, the utility model is near the protection critical point, from start control to control death (completely cut off the load RL circuit), the battery E voltage only needs to change tens of millivolts.

RP2 is used to adjust the protection critical starting control point, RP3 can also adjust the protective critical starting control point within a certain range, VS is a damped VMOS power field effect transistor, its maximum current is 30A, and the saturation voltage drop is 0.1-0.3V. The gate-source critical turn-on voltage is about 4V. When the load RL is powered by battery E and the voltage is above the set value V1, U2 outputs high level, VS is fully turned on, and the load works normally. When the voltage of battery E drops to V1, the output terminal of U2 is low level, VS Completely cut off, cut off the load RL circuit, thus avoiding the occurrence of over-discharge; light-emitting diode LED is used to indicate the working state of the circuit.

It is obvious to those skilled in the art that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from all points of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, so it is intended to be included in the claims All changes within the meaning and range of equivalents of the required elements are included in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned.

In addition, it should be understood that although this specification is described according to implementation modes, not each implementation mode only contains an independent technical solution, and this description in the specification is only for clarity, and those skilled in the art should take the specification as a whole , the technical solutions in the various embodiments can also be properly combined to form other implementations that can be understood by those skilled in the art.

Claims (3)

1. an over-discharge protection circuit, including resistance R3, electric capacity C1, potentiometer RP2, amplifier U2, electricity Position device RP3, band damping field effect transistor VS and LED, it is characterised in that described resistance R3 mono- End connects battery E positive pole, diode D5 positive pole, resistance R4, electric capacity C1 and potentiometer RP2 one end respectively, The resistance R3 other end connects diode D4 positive pole, and diode D4 negative pole connects diode D5 negative pole respectively and sends out Optical diode LED positive pole, LED negative pole connects load RL, and the load RL other end connects band resistance The D pole of Buddhist nun's field effect transistor VS, the S pole of band damping field effect transistor VS connects potentiometer RP3 one end, electricity respectively The position device RP2 other end, the electric capacity C1 other end, diode D6 Anode and battery E negative pole ground connection, band damps The G pole of field effect transistor VS connects potentiometer RP3 slide plate, and the potentiometer RP3 other end connects amplifier U2 outfan, Amplifier U2 in-phase end connect potentiometer RP2 slide plate, amplifier U2 end of oppisite phase connect respectively the resistance R4 other end and Diode D6 negative pole.

Over-discharge protection circuit the most according to claim 1, it is characterised in that described diode D6 is Zener diode.

Over-discharge protection circuit the most according to claim 1, it is characterised in that described amplifier U2 uses LM324。