Output voltage conduction control circuit
By using a voltage divider and diode detection circuit composed of thyristor and MOS tube in the charger, the load type is automatically identified, which solves the problem that the charger cannot identify abnormal loads, and achieves low-cost charger protection and power saving.
Patent Information
- Application Number
- CN202422204647.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2025-08-22
- Estimated Expiration
- 2034-09-09
AI Technical Summary
The existing charger circuit cannot identify the type of load connected, resulting in charging operations for abnormal loads, resulting in unnecessary power loss.
The detection circuit consisting of a voltage divider and a diode composed of thyristor and MOS tube is used to automatically identify abnormal loads using the remaining voltage of the battery, control the conduction of the charger output voltage, and realize the protection and control of the circuit through the cooperation of the MOS tube and the thyristor.
Automatic identification of abnormal loads is realized, unnecessary charging operations and power losses are reduced, and the charger is protected from damage. The circuit structure is simple and cost-effective.
Smart Images
Figure CN223261297U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of battery charging, in particular to an output voltage conduction control circuit. Background Art
[0002] With the rapid development of the economy and the improvement of people's living standards, rechargeable batteries are widely used in electrical appliances. Rechargeable batteries need to be charged after the power is exhausted. In existing charger circuits, the charger charging output voltage is usually connected to the charging output terminal. This has a defect. Regardless of whether the load connected to the battery terminal of the charger is a battery or a resistor, the charger will immediately charge the connected load output voltage without identifying the load. When the charger enters the charging working state, the internal detection circuit of the charger detects that the connected load is an abnormal load and then activates the internal control circuit to stop outputting the charging voltage, thereby terminating charging the abnormal load. Utility Model Content
[0003] In view of this, it is necessary to provide a charger charging output voltage control circuit with a simple circuit structure, low cost, good versatility, and the ability to identify abnormal loads connected to the charger's charging output voltage terminal and easily achieve charging output voltage conduction.
[0004] An output voltage conduction control circuit includes a thyristor Q1, a MOS transistor Q2, a diode D1, a diode D2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a power output terminal, and a battery input interface. The positive electrode of the power output terminal is connected to the source of the MOS transistor Q2, the positive electrode of the battery input interface, and the first end of the resistor R3 through the diode D2. The second end of the resistor R3 is connected to the gate of the MOS transistor Q2 and the first end of the resistor R4. The second end of the resistor R4 is connected to the negative electrode of the battery input interface and the anode A of the thyristor Q1. The negative electrode of the power output terminal is connected to the first end of the capacitor C1 and the positive electrode of the resistor R2. The first end and the second end of capacitor C1 are connected to the first end of resistor R1 and the positive electrode of diode D1. The negative electrode of the battery input interface is connected to the first end of resistor R4. The second end of resistor R4 is connected to the gate of MOS transistor Q2. The second end of resistor R1 is connected to the drain of MOS transistor Q2. The second end of resistor R2 is connected to the cathode K of thyristor Q1. The negative electrode of diode D1 is connected to the control electrode G of thyristor Q1. Resistors R3 and R4 form a voltage divider to divide the battery voltage. The connection end of resistors R3 and R4 is the output end of the voltage divider, which is connected to the gate of MOS transistor Q2. The output voltage of the voltage divider serves as the bias voltage of the gate of MOS transistor Q2.
[0005] Furthermore, when no battery is connected to the BAT+ and BAT- terminals of the battery input interface, the voltage between the gate and source of the MOS tube Q2 is low, so that the MOS tube Q2 cannot be turned on, and the power output terminal and the control circuit cannot form a loop. When the MOS tube Q2 is not turned on, the diode D1 is not turned on, the thyristor Q1 is not turned on, and the charging voltage at the power output terminal is disconnected between the anode A and cathode K of the thyristor Q1, and the battery input interface has no input voltage.
[0006] Furthermore, after a battery is connected to the BAT+ and BAT- terminals of the battery input interface, the remaining battery voltage is divided by resistors R4 and R3 to provide a bias voltage to the gate of the MOS transistor Q2, causing the MOS transistor Q2 to turn on. The battery voltage is connected to the positive electrode of the diode D1 through the source and drain of the MOS transistor Q2. When the diode D1 turns on, a positive trigger voltage can be applied between the control electrode G and the anode A of the thyristor Q1, causing conduction between the anode A and the cathode K of the thyristor Q1. The power output port is connected to the battery input interface to charge the battery and achieve output voltage conduction control. After the thyristor Q1 is turned on, as long as a positive voltage and a certain current are maintained between the anode A and the cathode K of the thyristor Q1, the thyristor Q1 can remain in the on state after the trigger voltage is removed.
[0007] Furthermore, the diode D2 is an anti-backflow protection diode, which is an isolation protection circuit between the battery input interface BAT+, BAT- and the power output terminals VO+, VO-. After the battery is connected to the BAT+ and BAT- ends of the battery input interface, if the battery voltage is higher than the output voltage of the charger, or a short circuit fault occurs at the power output terminals VO+ and VO-, the diode D2 is cut off, and the battery current cannot flow back to the power output terminals VO+ and VO-, thereby preventing the battery voltage from flowing back and damaging the charger.
[0008] The output voltage conduction control circuit utilizes the residual voltage of the battery to be charged and a detection circuit consisting of resistors R3, R4, and a transistor to automatically identify abnormal loads connected to the charger and control the charger's output voltage to conduct when the battery is connected. The circuit structure is simple, can reduce unnecessary charging operations of the charger, and avoid unnecessary power loss. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Figure 1 It is a circuit diagram of the output voltage conduction control circuit of an embodiment of the utility model. DETAILED DESCRIPTION
[0010] The present invention will be described in detail below with reference to specific embodiments and accompanying drawings.
[0011] See also Figure 1, shows an output voltage conduction control circuit provided by an embodiment of the present utility model, including a thyristor Q1, a MOS tube Q2, a diode D1, a diode D2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a power output terminal, and a battery input interface. The positive electrode of the power output terminal is connected to the source of the MOS tube Q2, the positive electrode of the battery interface, and the first end of the resistor R3 through the diode D2. The second end of the resistor R3 is connected to the gate of the MOS tube Q2 and the first end of the resistor R4. The second end of the resistor R4 is connected to the negative electrode of the battery input interface and the anode A of the thyristor Q1. The negative electrode of the power output terminal is connected to the first end of the capacitor C1 and the The first end and the second end of the capacitor C1 are connected to the first end of the resistor R1 and the positive electrode of the diode D1. The negative electrode of the battery input interface is connected to the first end of the resistor R4. The second end of the resistor R4 is connected to the gate of the MOS transistor Q2. The second end of the resistor R1 is connected to the drain of the MOS transistor Q2. The second end of the resistor R2 is connected to the cathode K of the thyristor Q1. The negative electrode of the diode D1 is connected to the control electrode G of the thyristor Q1. The resistors R3 and R4 form a voltage divider to divide the battery voltage. The connection end of the resistors R3 and R4 is the output end of the voltage divider, which is connected to the gate of the MOS transistor Q2. The output voltage of the voltage divider serves as the bias voltage of the MOS transistor Q2.
[0012] Furthermore, when no battery is connected to the BAT+ and BAT- ends of the battery input interface, the voltage between the gate and source of the MOS tube Q2 is extremely low, the MOS tube Q2 cannot be turned on, and the power output end and the control circuit cannot form a loop. The MOS tube Q2 does not conduct, the diode D1 does not conduct, and the voltage between the thyristor control electrode G and the cathode K does not reach the trigger voltage of the thyristor. The thyristor anode A and the cathode K cannot conduct, so the thyristor Q1 does not conduct, the charging voltage output by the power supply is disconnected by the thyristor Q1 anode A and the cathode K, and the battery input interface has no input voltage.
[0013] Furthermore, after the battery is connected to the BAT+ and BAT- terminals of the battery input interface, the remaining voltage of the battery is divided by resistors R4 and R3 to provide a bias voltage to the gate of the MOS transistor Q2, causing the MOS transistor Q2 to turn on. The battery voltage is connected to the positive electrode of the diode D1 through the source and drain of the MOS transistor Q2. The diode D1 is turned on, and a positive trigger voltage is applied between the control electrode G and the anode A of the thyristor Q1. The anode A and the cathode K of the thyristor Q1 are turned on. The power output port is connected to the battery input interface to charge the battery and realize output voltage conduction control. After the thyristor Q1 is turned on, as long as a positive voltage and a certain current are maintained between the anode A and the cathode K of the thyristor Q1, the thyristor Q1 can remain in the on state after the trigger voltage is removed. The unidirectional conductivity of the diode D1 ensures that the polarity of the trigger voltage applied between the control electrode G and the anode A of the thyristor Q1 is positive.
[0014] Furthermore, the diode D2 is an anti-backflow protection diode, which is an isolation protection circuit between the battery input interface BAT+, BAT- and the power output terminals VO+, VO-. After the battery is connected to the BAT+ and BAT- ends of the battery input interface, if the battery voltage is higher than the output voltage of the charger, or a short circuit fault occurs at the power output terminals VO+, VO-, the diode D2 is cut off, and the battery current cannot flow back to the power output terminals VO+, VO-, thereby preventing the battery current from flowing back and damaging the charger.
[0015] The above-mentioned output voltage conduction control circuit uses the residual voltage of the battery to be charged and the detection circuit composed of resistors R3, R4, and MOS tube Q2 to automatically identify abnormal loads connected to the charger and control the conduction connection between the charger's output voltage and the battery input interface, which can reduce unnecessary power loss of the charger. Products using this circuit have a simple circuit structure, are easy to produce, low cost, and are easy to promote.
[0016] It should be noted that the present invention is not limited to the above-mentioned embodiments. According to the creative spirit of the present invention, those skilled in the art can also make other changes. These changes made according to the creative spirit of the present invention should be included in the scope of protection required by the present invention.
Claims
1. An output voltage conduction control circuit, characterized in that: It includes a thyristor Q1, a MOS tube Q2, a diode D1, a diode D2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a power output terminal, and a battery input interface. The positive electrode of the power output terminal is connected to the source of the MOS tube Q2, the positive electrode of the battery input interface, and the first end of the resistor R3 through the diode D2. The second end of the resistor R3 is connected to the gate of the MOS tube Q2 and the first end of the resistor R4. The second end of the resistor R4 is connected to the negative electrode of the battery input interface and the anode A of the thyristor Q1. The negative electrode of the power output terminal is connected to the first end of the capacitor C1, the first end of the resistor R2, and the second end of the capacitor C1 is connected to the The first end of resistor R1, the positive electrode of diode D1, and the negative electrode of the battery input interface are connected to the first end of resistor R4. The second end of resistor R4 is connected to the gate of MOS transistor Q2. The second end of resistor R1 is connected to the drain of MOS transistor Q2. The second end of resistor R2 is connected to the cathode K of thyristor Q1. The negative electrode of diode D1 is connected to the control electrode G of thyristor Q1. Resistors R3 and R4 form a voltage divider to divide the battery voltage. The connection end of resistors R3 and R4 is the output end of the voltage divider, which is connected to the gate of MOS transistor Q2. The output voltage of the voltage divider serves as the bias voltage of the gate of MOS transistor Q2.
2. The output voltage conduction control circuit according to claim 1, wherein: When no battery is connected to the BAT+ and BAT- terminals of the battery input interface, the voltage between the gate and source of the MOS transistor Q2 is low, so that the MOS transistor Q2 cannot be turned on. The power output terminal and the control circuit cannot form a loop. The MOS transistor Q2 does not conduct, the diode D1 does not conduct, the thyristor Q1 does not conduct, the charging voltage output by the power supply is disconnected between the anode A and cathode K of the thyristor Q1, and the battery input interface has no input voltage.
3. The output voltage conduction control circuit according to claim 2, wherein: After a battery is connected to the BAT+ and BAT- terminals of the battery input interface, the remaining battery voltage is divided by resistors R4 and R3 to provide a bias voltage to the gate of the MOS transistor Q2, causing the MOS transistor Q2 to conduct. The battery voltage is connected to the positive electrode of the diode D1 through the source and drain of the MOS transistor Q2. The diode D1 is turned on, and a forward trigger voltage is applied between the control electrode G and the anode A of the thyristor Q1. The anode A and the cathode K of the thyristor Q1 are turned on. The power output port is connected to the battery input interface to charge the battery, thereby achieving output voltage conduction control.
4. The output voltage conduction control circuit according to claim 1, wherein: The diode D2 is an anti-backflow protection diode.