CN102157976B - An Electric Bicycle Battery Charging Circuit That Can Identify Voltage - Google Patents

Abstract

The invention relates to an electric bicycle battery charging circuit capable of identifying voltage, including a leakage protector, characterized in that: the leakage protector is connected to one of the incoming lines of the power supply and then connected to a capacitor through a fuse, and the other of the capacitor and the power supply The incoming line is connected to the rectifier bridge, and a capacitor for filtering is connected in parallel at the output end of the rectifier bridge, and then two Zener diodes are connected in parallel to form an auxiliary power supply with output DC 12V. The voltage value of the circuit 40V, 42V, 53V, two voltage comparators constitute the core part of the comparison circuit. The invention can automatically detect the rated voltage value of the charged electric bicycle battery, and adjust the voltage value of the rechargeable battery after it is fully charged according to the rated value, so as to automatically charge all qualified electric bicycle batteries on the market, and automatically cut off the battery after it is fully charged. It has good practical value.

Description

An Electric Bicycle Battery Charging Circuit That Can Identify Voltage

technical field

The invention relates to an electric bicycle battery charging circuit capable of identifying voltages, which can charge all currently listed qualified electric bicycle batteries.

Background technique

Electric bicycles have been widely used in our daily life. The batteries used in the car are 36V and 48V. The chargers are designed by various manufacturers for different types of batteries and voltages. There is no universality. At present, electric bicycle chargers are all It adopts switching power supply, uses many components, complex circuit, and low reliability.

Contents of the invention

In view of this, the present invention provides an electric bicycle battery charging circuit capable of identifying voltage, which can charge all currently listed qualified electric bicycle batteries.

The invention relates to an electric bicycle battery charging circuit capable of identifying voltage, comprising a leakage protector, a fuse, a capacitor, a rectifier bridge, a detection circuit, a comparison circuit, a control circuit and an auxiliary power supply circuit, characterized in that the leakage protector One of the incoming lines of the external AC 220V power supply is connected to a capacitor connected in parallel with a discharge resistor through a fuse. The capacitor and the other incoming line of the power supply are connected to the input terminal of the rectifier bridge, and the output terminal of the rectifier bridge is connected to the normally open contact of the relay K. It is connected with the ammeter and the charging battery, and the two ends of the battery are connected in parallel with a detection circuit composed of resistors connected in series. The rear end of the fuse is connected with a 220V AC power supply and connected to a capacitor and a rectifier bridge to form an auxiliary power supply circuit. The output of the rectifier bridge is connected in parallel with a filter capacitor, and then Two Zener diodes are connected in parallel to form an auxiliary power supply that outputs DC 12V. Four voltage dividing resistors are connected in parallel at the output end of the auxiliary power supply to take out the voltage values corresponding to the detection circuit 40V, 42V, and 53V respectively. Two voltage comparators form a comparison circuit. The core part of the comparator, each input terminal of the comparator is connected to a resistor, and the two negative input terminals are connected in parallel to the output of the detection circuit. The positive input terminal of the first comparator is connected to the auxiliary power supply circuit through a relay, which corresponds to the detection circuit 40V The voltage value of 53V, the voltage value of the auxiliary power supply circuit corresponding to the detection circuit 42V is connected to the positive input terminal of the second comparator, the output terminals of the two comparators are connected to the bases of two NPN transistors through a resistor, and the first comparator The collector of the connected triode is connected to the coil of the relay K, the collector of the triode connected to the second comparator is connected to the coil of the _relay K, the two relay coils are connected to the positive pole of the 12V power supply, and the emitters of the two triodes are grounded , the comparator is also powered by the 12V supply. The invention can automatically detect the rated voltage value of the battery of the charged electric bicycle, and adjust the voltage value of the rechargeable battery after it is fully charged according to the rated value, so as to automatically charge all the qualified electric bicycle batteries of the above formula, and automatically cut off the battery after the battery is fully charged. Simultaneously, the circuit structure of the present invention is simple, the components used are few, and has good practical value.

Description of drawings

Fig. 1 is a schematic block diagram of the circuit of the present invention.

Fig. 2 is a circuit diagram of an embodiment of the present invention.

Detailed ways

Fig. 1 is a schematic block diagram of circuit composition, which is analyzed in conjunction with the circuit diagram of the specific embodiment in Fig. 2, including leakage protector Q1, fuse RD, capacitor C1, rectifier bridge, detection circuit, comparison circuit, control circuit and auxiliary power supply circuit, its characteristics That is: the leakage protector Q1 is connected to the external AC 220V power supply, and then connected to the capacitor C1 connected in parallel with the discharge resistor R1 through the fuse RD. The point and the ammeter are connected to the charging battery, and the two ends of the battery are connected in parallel to a detection circuit composed of resistors (R2/R3/R4) in series, and the above parts constitute the main charging circuit. The rear end of the fuse RD takes 220V AC power supply and connects capacitor C2 and rectifier bridge to form an auxiliary power supply circuit. The output terminal of the rectifier bridge is connected in parallel with a capacitor C3 for filtering, and then two Zener diodes are connected in parallel to form an auxiliary power supply that outputs DC 12V. Four voltage divider resistors (R5/R6/R7/R8) are connected in parallel at the output end. By selecting the appropriate resistance value, the voltage values corresponding to the detection circuit 40V, 42V, and 53V can be taken out respectively. Two voltage comparators U1A/U2A constitute the core part of the comparison circuit. The input terminals of the two comparators are connected to R10/R12 resistors, and the negative input terminals are connected in parallel to the output of the detection circuit. The positive input terminal of U1A is connected to the auxiliary power supply through the resistor R9 relay K The circuit corresponds to the voltage of the detection circuit 40V, 53V, the auxiliary power supply circuit corresponds to the voltage value of the detection circuit 42V connected to the positive input terminal of U2A through the resistor R11, and the output terminals of the two comparators are connected to the NPN transistor T1/T2 through the resistor R13/14 The base, the T1 collector is connected to the coil of the relay K, the T2 collector is connected to the coil of the _relay K, the two relay coils are connected to the positive pole of the 12V power supply, the transmitters of the two triodes are grounded, and the comparator is powered by the 12V power supply. Capacitors C1/C2 in the circuit use AC capacitors with high withstand voltage values, and the maximum charging current can be adjusted by adjusting the capacitance value. Since the circuit does not use an isolation transformer for electrical isolation, in order for the circuit to work safely, it is connected to the circuit. leakage protector.

There are two types of electric bicycle batteries currently on the market, 36V and 48V. The back-end voltage of a 36V battery will not exceed 42V when it is fully charged, while the minimum discharge of a 48V battery will not be lower than 42V, and the maximum charge will not exceed 53V. Therefore, the circuit selects 42V as The critical voltage point is used to judge the type of battery connected. When the detection value is higher than 42V, it means that the connected battery is 48V, U1A output is high, K acts, U2A output is low, K _detection does not act, given 53V, the battery is charged, when the battery is charged to 53V, U1A output is low, K off, stop charging. When the detection voltage is lower than 42V, it means that the connected battery is 36V, U1A output is high, K action, U2A output is high, K _detection action, given 40V, the battery is charged, when the battery is charged to 40V, U1A The output is low, K is off, and charging stops. When the detection value is 40<detection value<42, it means that the battery is 36V. At this time, the power is relatively sufficient, and K _checks through, and K fails, which will not cause harm.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims (6)

1. An electric bicycle battery charging circuit capable of identifying voltage comprises a leakage protector, a fuse, capacitors C1, C2, a bridge rectifier, a detection circuit, a comparison circuit, a control circuit and an auxiliary power supply circuit, and is characterized in that: said leakage The protector is connected to one of the incoming lines of the external AC 220V power supply, and then connected to the capacitor C1 connected in parallel with the discharge resistor R1 through a fuse. The capacitor C1 and the other incoming line of the external AC 220V power supply are connected to the input terminal of the first rectifier bridge. The output end of the rectifier bridge is connected to the charged battery through the normally open contact of the relay K and the ammeter in turn, and the two ends of the battery are connected in parallel to a detection circuit composed of resistors in series, and the front end of the fuse is connected to the external AC through a leakage protector. One of the incoming lines of the 220V power supply, the rear end is connected to one end of the capacitor C2, the other end of the capacitor C2 and the other incoming line of the external AC 220V power supply are connected to the input end of the second rectifier bridge to form an auxiliary power supply circuit; the output end of the second rectifier bridge Connect a capacitor C3 for filtering in parallel, and then connect two Zener diodes in parallel to form an auxiliary power supply that outputs DC 12V. Connect four voltage dividing resistors in parallel at the output end of the auxiliary power supply to take out the voltage values corresponding to the detection circuit 40V, 42V, and 53V respectively. Two voltage comparators constitute the core part of the comparison circuit. After each input terminal of the two voltage comparators is connected to a resistor, the two negative input terminals are connected in parallel to the output of the detection circuit, and the positive input terminal of the first voltage comparator The terminal is connected to the voltage value corresponding to the detection circuit 40V and 53V of the auxiliary power supply circuit _through the relay K, and the voltage value of the auxiliary power supply circuit corresponding to the detection circuit 42V is connected to the positive input terminal of the second voltage comparator, and the voltage values of the two voltage comparators The output terminal is connected to the bases of two NPN transistors through a resistor, the collector of the transistor connected to the first voltage comparator is connected to the coil of relay K, and the collector of the transistor connected to the second voltage comparator is connected to the relay K to _detect Coil, the two relay coils are connected to the positive pole of the 12V power supply, the emitters of the two triodes are grounded, and the two voltage comparators are also powered by the 12V power supply. The electric bicycle battery charging circuit adjusts the charging given value according to the detected value of the battery terminal voltage. It can meet the charging requirements of different types of electric bicycle batteries. 2. The electric bicycle battery charging circuit capable of identifying voltage according to claim 1, characterized in that: the capacitor C1 connected to the external AC 220V power supply is an AC capacitor, its size is selected according to the capacity of the battery, and the resistor R1 plays a role in discharging . 3. The electric bicycle battery charging circuit capable of identifying voltage according to claim 2, characterized in that: the capacity of the AC capacitor comprises 24 μF. 4. The electric bicycle battery charging circuit capable of identifying voltage according to claim 1, characterized in that: the comparison circuit is composed of 4 resistors, 2 voltage comparators, and K- _detection contacts; the auxiliary power supply circuit is composed of 1 AC capacitor, 1 rectifier bridge, 1 filter capacitor, 2 voltage regulator tubes, 4 voltage divider resistors; the control circuit consists of 2 resistors, 2 NPN transistors, and 2 relays. 5. The electric bicycle battery charging circuit capable of identifying voltage according to claim 1, wherein the voltage comparator is an all-in-one comparator chip. 6. The electric bicycle battery charging circuit capable of identifying voltage according to claim 5, characterized in that: the comparator chip includes LM393.

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