CN202918037U - Electric bicycle charger - Google Patents

Abstract

The utility model discloses an electric bicycle charger. The charger comprises a power supply interface, the power supply interface is connected with a first rectification and filtering circuit through an electromagnetic relay, the first rectification and filtering circuit is connected with a switch tube, the switch tube is connected with a PWM controller and a switch transformer, the switch transformer is connected with a second rectification and filtering circuit, the second rectification and filtering circuit is connected with a storage battery, the storage battery is connected with an electronic quantity detection circuit, the second rectification and filtering circuit is connected with a voltage stabilizing circuit, the voltage stabilizing circuit is connected with the electric quantity detection circuit, the electric quantity detection circuit is connected with a shutdown circuit, the voltage stabilizing circuit is connected with the shutdown circuit, and the shutdown circuit is connected with the electromagnetic relay. The electric bicycle charger has stable and reliable performance and high response speed, an input power supply of the charger can be cut off automatically, and mistaken shutdown of the shutdown circuit during starting up can be prevented, misoperation when a user manually cuts off the power supply can be prevented, and the life of the charger and the life of the battery are prolonged.

Description

electric bike charger

technical field

The utility model relates to a charging device, in particular to an electric bicycle charger. the

Background technique

The charger is a device for charging the battery. It is one of the four core components of the electric bicycle. It determines the charging time and the life of the battery. Its technical research is relatively mature. At present, electric bicycle chargers are mostly based on the switching principle to convert AC power into DC power. The general process of work is: 220V AC power is converted into DC power through rectification and filtering, and then converted into AC power through the switch tube under the control of adjustable pulse width. After the transformer is transformed, the alternating current is output from the secondary, and then rectified and filtered to become the required direct current voltage. However, the current chargers based on the switch principle in use on the market have the disadvantage of not being able to automatically cut off the power after charging is completed, which will cause the following hazards:

1. After the battery is fully charged, as long as the user does not cut off the input power of the charger, the charger will continue to charge the battery, which will shorten the life of the charger, increase the failure rate of the charger, and easily cause other unsafe accidents. the

2. The charger keeps charging the battery, wasting electric energy, which is neither economical nor environmentally friendly. the

3. When stopping charging the battery, the input plug between the charger and the external power supply should be disconnected first, and then the output plug between the charger and the battery should be disconnected. Users often cannot remember the sequence and misoperation will easily cause charger failure. . the

Utility model content

In view of the above-mentioned defects of the prior art, the technical problem to be solved by the utility model is to provide an electric bicycle charger capable of realizing automatic power-off protection. the

In order to achieve the above object, the utility model provides an electric bicycle charger, including a power interface connected to the AC power supply; the output end of the power interface is connected to the input end of the first rectification and filtering circuit through the switch end of the electromagnetic relay; The output end of the first rectifying and filtering circuit is connected to the first input end of the switching tube; the second input end of the switching tube is connected to the output end of the PWM controller; the output end of the switching tube is connected to the input end of the switching transformer; The output end of the switching transformer is connected to the input end of the second rectification filter circuit; the first output end of the second rectification filter circuit is connected to the input end of the storage battery; the output end of the storage battery is connected to the first input end of the power detection circuit; The second output end of the second rectification and filtering circuit is connected to the input end of the voltage stabilizing circuit; the first output end of the voltage stabilizing circuit is connected to the second input end of the power detection circuit; the output end of the power detection circuit is connected to the shutdown The first input end of the circuit; the second output end of the voltage stabilizing circuit is connected to the second input end of the shutdown circuit; the output end of the shutdown circuit is connected to the input end of the electromagnetic relay. the

After the charging is completed, the utility model can automatically cut off the input power of the charger, avoiding the misoperation caused by manual power-off by the user, increasing the life of the charger, reducing the failure rate of the charger, and saving electric energy at the same time, which is environmentally friendly and economical. the

Preferably, the shutdown circuit includes a first diode; the cathode of the first diode is connected to the cathode of the Zener diode; the anode of the Zener diode is connected to the emitter of the first NPN transistor through the first capacitor. pole; the emitter of the first NPN triode is grounded; the collector of the first NPN triode is connected to the negative pole of the second diode through the electromagnetic coil of the electromagnetic relay; the positive pole of the second diode A first resistor is connected; a third diode is connected in parallel between the collector of the first NPN transistor and the electromagnetic coil of the electromagnetic relay; the anode of the third diode is connected to the first NPN transistor. The collector of the transistor; the negative pole of the third diode is grounded through the second capacitor; the base of the first NPN transistor is connected to the collector of the PNP transistor through the second resistor; the PNP transistor's The emitter is connected to the cathode of the first diode; the base of the first NPN transistor is connected to the cathode of the fourth diode; the anode of the fourth diode is connected to the emitter of the second NPN transistor The collector of the second NPN transistor is connected to the anode of the first diode through a third resistor; the base of the PNP transistor is connected to the anode of the first diode through a fourth resistor; The anode of the first diode is connected to the second output terminal of the voltage stabilizing circuit; the second diode is connected to the second output terminal of the voltage stabilizing circuit through a first resistor; the second NPN transistor The base of the utility model is connected to the output terminal of the power detection circuit, and the shutdown circuit of the utility model has stable and reliable performance and fast response speed. the

Further, the utility model also includes a feedback circuit; the third output terminal of the second rectification and filtering circuit is connected to the input terminal of the feedback circuit; the output terminal of the feedback circuit is connected to the input terminal of the PWM controller; the PWM The controller controls the conduction time of the switch tube according to the voltage fed back by the feedback circuit, so that the switch tube can output a DC voltage stably. the

Preferably, the voltage stabilizing circuit is a silicon Zener diode voltage stabilizing circuit. the

The beneficial effects of the utility model are: the utility model has stable and reliable performance and fast response speed. The utility model can automatically cut off the input power of the charger, and at the same time, it can avoid the wrong shutdown of the shutdown circuit when the power is turned on, and avoid the occurrence of manual power failure by the user. Misoperation increases the life of the charger, reduces the failure rate of the charger, and saves power, which is environmentally friendly and economical. the

Description of drawings

Fig. 1 is a schematic diagram of the circuit principle of the utility model. the

FIG. 2 is a schematic diagram of the circuit structure of the shutdown circuit 11 in a specific embodiment of the present invention. the

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described:

As shown in Figure 1, an electric bicycle charger includes a power interface 1 connected to an AC power supply, the output end of the power interface 1 is connected to the input end of the first rectification filter circuit 3 through the switch end of the electromagnetic relay 2, so The output end of the first rectifying and filtering circuit 3 is connected to the first input end of the switch tube 4, the second input end of the switch tube 4 is connected to the output end of the PWM controller 5, and the output end of the switch tube 4 is connected to the switching transformer 6, the output end of the switching transformer 6 is connected to the input end of the second rectification filter circuit 7, the first output end of the second rectification filter circuit 7 is connected to the input end of the battery 8, and the output of the battery 8 terminal is connected to the first input terminal of the power detection circuit 9, and the second output terminal of the second rectification filter circuit 7 is connected to the input terminal of the voltage stabilizing circuit 10, and the voltage stabilizing circuit 10 is a silicon Zener diode voltage stabilizing circuit, so The third output terminal of the second rectifying and filtering circuit 7 is connected to the input terminal of the feedback circuit 12, the output terminal of the feedback circuit 12 is connected to the input terminal of the PWM controller 5, and the first voltage stabilizing circuit 10 The output terminal is connected to the second input terminal of the power detection circuit 9, the output terminal of the power detection circuit 9 is connected to the first input terminal of the shutdown circuit 11, and the second output terminal of the voltage stabilizing circuit 10 is connected to the shutdown circuit 11. The second input terminal, the output terminal of the shutdown circuit 11 is connected to the input terminal of the electromagnetic relay 2 . the

The 220V alternating current becomes 300V direct current through the first rectifying and filtering circuit 3 and then enters the switching tube 4. The PWM controller 5 controls the switching tube 4 to convert the 300V direct current into alternating current. stage output alternating current, and then through the second rectification and filtering circuit 7 to become the required DC voltage to charge the storage battery, and at the same time, the second rectification and filtering circuit 7 sends a signal to the PWM controller 5 through the feedback circuit 12, and the PWM controller controls the conduction of the switching tube 4 The on-time is used to stabilize the DC voltage output. Along with charging, the electric quantity of accumulator 8 increases, after detecting that accumulator 8 electric quantity is full, electric quantity detecting circuit 9 sends the voltage signal of shutting down to shutdown circuit 11, and shutting down circuit 11 action disconnects electromagnetic relay 2, cuts off the power of charger. Input voltage. the

In order to make the performance of the shutdown circuit 11 more stable and reliable, and to respond quickly, and to prevent the shutdown circuit 11 from malfunctioning and shutting down when starting up, the shutdown circuit 11 is realized by the following structure: the negative electrode of the first diode D1 is connected to The cathode of the Zener diode D2, the anode of the Zener diode D2 is connected to the emitter of the first NPN transistor Q1 through the first capacitor C1, the emitter of the first NPN transistor Q1 is grounded, and the first NPN transistor Q1 is grounded. The collector of the triode Q1 is connected to the cathode of the second diode D3 through the electromagnetic coil of the electromagnetic relay 2, the anode of the second diode D3 is connected to the first resistor R1, and the first NPN transistor Q1 A third diode D4 is connected in parallel between the collector and the electromagnetic coil of the electromagnetic relay 2, the anode of the third diode D4 is connected to the collector of the first NPN transistor Q1, the third two The negative electrode of the transistor D4 is grounded through the second capacitor C2, the base of the first NPN transistor Q1 is connected to the collector of the PNP transistor Q2 through the second resistor R2, and the emitter of the PNP transistor Q2 is connected to the first a cathode of a diode D1, the base of the first NPN transistor Q1 is connected to the cathode of the fourth diode D5, and the anode of the fourth diode D5 is connected to the emitter of the second NPN transistor Q3, The collector of the second NPN transistor Q3 is connected to the anode of the first diode D1 through the third resistor R3, and the base of the PNP transistor Q2 is connected to the first diode through the fourth resistor R4 The anode of D1, the anode of the first diode D1 is connected to the second output terminal of the voltage stabilizing circuit 10, and the second diode D3 is connected to the second output terminal of the voltage stabilizing circuit 10 through the first resistor R1. Output terminal, in order to protect the circuit, the power interface 1 is connected to the switch terminal of the electromagnetic relay through the sixth resistor R6, and the base of the second NPN transistor Q3 is connected to the output terminal of the power detection circuit 9 through the fifth resistor R5 , the regulated voltage value of the voltage stabilizing diode D2 is smaller than the voltage value of the output power supply of the voltage stabilizing circuit 10 . the

Wherein the bias function of the third resistor R3, the second capacitor C2 uses the stored electric energy as a power supply and the power output of the voltage stabilizing circuit 10 to supply power to the electromagnetic coil of the electromagnetic relay 2 and the first NPN transistor Q1 when the power is turned off. The smooth completion of the shutdown action is ensured; when the shutdown occurs, the first capacitor C1 supplies power to the base of the first NPN transistor Q1 through the Zener diode D2, the PNP transistor Q2, and the second resistor R2. At this time, the PNP transistor Q2 saturates and conducts At this time, the first diode D1 plays an isolation role, preventing the electric energy stored on the first capacitor C1 from supplying power to other places; the third diode D4 is connected in parallel with the electromagnetic coil of the electromagnetic relay 2, and the electromagnetic coil after shutdown The induced voltage generated is discharged to prevent the induced voltage from breaking down the first NPN transistor Q1; the second diode D3 acts as an isolation to prevent the induced voltage generated by the electromagnetic coil from causing damage to other components; the fourth diode D5 It acts as an isolation to prevent any one of the PNP transistor Q2 and the second NPN transistor Q3 from being damaged and affecting the realization of the shutdown action during shutdown. the

After the shutdown circuit 11 receives the shutdown voltage signal from the power detection circuit 9, that is, after the base of the second NPN transistor Q3 receives the signal from the power detection circuit 9, the first NPN transistor Q1 and the second NPN The composite tube composed of the NPN triode Q3 is saturated and turned on, and the regulated power supply current output by the voltage stabilizing circuit 10 flows to the collector of the first NPN triode Q1 through the first resistor R1, the second diode D3, and the electromagnetic coil of the electromagnetic relay 2 , The magnetic field generated when the current flows through the electromagnetic coil of the electromagnetic relay 2 attracts the armature and turns off the self-locking switch, thereby cutting off the input voltage of the charger. the

Because when the power is just turned on, each pole of the triode will have a small current. If the triode of the shutdown circuit is in an amplified state at this time, the shutdown circuit will perform a shutdown action, causing the charger to fail to work normally. In the present invention, the voltage stabilizing circuit 10 outputs the regulated power supply to the shutdown circuit 11 and the power detection circuit 9, and the collector of the second NPN transistor Q3 immediately obtains a non-zero voltage, but at this time the base voltage of the second NPN transistor Q3 is zero, and Q3 It is an NPN transistor, and its base voltage is zero, so the base current of the second NPN transistor Q3 is zero, so the second NPN transistor Q3 is in a cut-off state and will not supply current to the base of the first NPN transistor Q1 Simultaneously, the voltage stabilizing power output of the voltage stabilizing circuit 10 is added to the base of the PNP transistor Q2 through the fourth resistor R4, but at this moment, the stabilizing power supply output by the voltage stabilizing circuit 10 is connected to the voltage stabilizing diode by the first diode D1 D2 breaks down to charge the first capacitor C1. At this time, the voltage of the emitter of the PNP transistor Q2 is lower than the voltage of the output power supply of the voltage stabilizing circuit 10. Since Q2 is a PNP transistor, the voltage of the emitter is lower than the voltage of the base, so The PNP transistor Q2 is in the cut-off state, and the current of each pole is zero, and it will not provide current to the base of the first NPN transistor Q1; therefore, both the PNP transistor Q2 and the second NPN transistor Q3 are in the cut-off state when they are turned on. The first NPN type transistor Q1 is also in cut-off state, so when not receiving the shutdown signal of the power detection circuit 9, no current flows through the electromagnetic coil of the electromagnetic relay 2 in the shutdown circuit 11, thereby ensuring that the shutdown circuit 11 will not appear when starting Wrong shutdown action. the

The preferred specific embodiments of the present utility model have been described in detail above. It should be understood that those skilled in the art can make many modifications and changes according to the concept of the utility model without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the utility model through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the scope of protection defined by the claims . the

Claims (4)

1. a charger for electric bicycle comprises the power interface (1) that links to each other with AC power; The output of described power interface (1) connects the input of the first current rectifying and wave filtering circuit (3) by the tail end of switch of electromagnetic relay (2); It is characterized in that: the first input end of the output connecting valve pipe (4) of described the first current rectifying and wave filtering circuit (3); The second input of described switching tube (4) connects the output of PWM controller (5); The input of the output connecting valve transformer (6) of described switching tube (4); The output of described switch transformer (6) connects the input of the second current rectifying and wave filtering circuit (7); The first output of described the second current rectifying and wave filtering circuit (7) connects the input of storage battery (8); The output of described storage battery (8) connects the first input end of electric quantity detecting circuit (9); The second output of described the second current rectifying and wave filtering circuit (7) connects the input of voltage stabilizing circuit (10); The first output of described voltage stabilizing circuit (10) connects the second input of electric quantity detecting circuit (9); The output of described electric quantity detecting circuit (9) connects the first input end of shutdown circuit (11); The second output of described voltage stabilizing circuit (10) connects the second input of described shutdown circuit (11); The output of described shutdown circuit (11) connects the input of described electromagnetic relay (2).

2. charger for electric bicycle as claimed in claim 1, it is characterized in that: described shutdown circuit (11) comprises the first diode (D1); The negative pole of described the first diode (D1) connects the negative pole of voltage stabilizing didoe (D2); The positive pole of described voltage stabilizing didoe (D2) connects the emitter of a NPN type triode (Q1) by the first electric capacity (C1); The grounded emitter of a described NPN type triode (Q1); The collector electrode of a described NPN type triode (Q1) connects the negative pole of the second diode (D3) by the solenoid of described electromagnetic relay (2); The positive pole of described the second diode (D3) is connected with the first resistance (R1); Be parallel with the 3rd diode (D4) between the solenoid of the collector electrode of a described NPN type triode (Q1) and described electromagnetic relay (2); The positive pole of described the 3rd diode (D4) connects the collector electrode of a described NPN type triode (Q1); The negative pole of described the 3rd diode (D4) is by the second electric capacity (C2) ground connection; The base stage of a described NPN type triode (Q1) connects the collector electrode of positive-negative-positive triode (Q2) by the second resistance (R2); The emitter of described positive-negative-positive triode (Q2) connects the negative pole of described the first diode (D1); The base stage of a described NPN type triode (Q1) connects the negative pole of the 4th diode (D5); The positive pole of described the 4th diode (D5) connects the emitter of the 2nd NPN type triode (Q3); The collector electrode of described the 2nd NPN type triode (Q3) connects the positive pole of described the first diode (D1) by the 3rd resistance (R3); The base stage of described positive-negative-positive triode (Q2) connects the positive pole of described the first diode (D1) by the 4th resistance (R4); The positive pole of described the first diode (D1) connects the second output of described voltage stabilizing circuit (10); Described the second diode (D3) connects the second output of described voltage stabilizing circuit (10) by the first resistance (R1); The base stage of described the 2nd NPN type triode (Q3) connects the output of described electric quantity detecting circuit (9).

3. charger for electric bicycle as claimed in claim 1 or 2 is characterized in that: also comprise feedback circuit (12); The 3rd output of described the second current rectifying and wave filtering circuit (7) connects the input of described feedback circuit (12); The output of described feedback circuit (12) connects the input of described PWM controller (5).

4. charger for electric bicycle as claimed in claim 1 or 2, it is characterized in that: described voltage stabilizing circuit (10) is the silicon voltage regulator diode voltage stabilizing circuit.

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