Constant-current tail lamp circuit for electric scooter
A simplified constant current taillight circuit for mobility scooters and electric wheelchairs uses a transistor and diodes to address the lack of effective current control, ensuring reliable operation and cost-efficiency.
Patent Information
- Application Number
- CN202421046064.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-14
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2034-05-14
AI Technical Summary
Existing mobility scooters and electric wheelchairs lack a simple and cost-effective constant current control for their taillights, which are often affected by battery status and lead to increased circuit control costs and reduced service life.
A constant current taillight circuit using a simplified design with one transistor, three diodes, and two resistors, including a battery voltage interface, diodes, resistors, and an NPN transistor, to control the current effectively and reduce costs.
The circuit provides robust constant current control with low costs, enhanced reliability, and increased lamp life, suitable for harsh environments with fluctuating battery voltages.
Smart Images
Figure CN222302054U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a scooter or an electric wheelchair, in particular to a constant current taillight circuit for an electric scooter used on the scooter or the electric wheelchair. Background Art
[0002] A mobility scooter or electric wheelchair usually refers to a means of transportation or auxiliary tool for the purpose of walking. It is usually used as a small car, electric bicycle, electric scooter, electric wheelchair, etc. to replace people's walking, so as to meet the needs of people with convenient mobility for longer distance travel, or meet the travel needs of people with inconvenience in mobility, so as to improve the efficiency of travel and other transportation tools or auxiliary tools. However, the taillight circuit of the existing mobility scooter or electric wheelchair does not have constant current control, which is easily affected by the battery status and working status of the mobility scooter or electric wheelchair, which is not conducive to improving the service life of the taillight, or some use more complex constant current control circuits, resulting in higher circuit control costs.
[0003] The authorized patent number ZL 201820323824.6, which was announced on March 9, 2018, discloses a voltage-stabilized constant-current LED taillight module with a protection circuit based on a triode. It mainly solves the technical problems that the existing taillight circuit is prone to surge, overvoltage, microcurrent and overpower of the power tube. The technical solution of the utility model is: a voltage-stabilized constant-current LED taillight module with a protection circuit based on a triode, including a power input unit, an overvoltage protection unit, a constant current control unit, an LED load unit and an LED constant current unit. The power input unit outputs an electrical signal that enters the overvoltage protection unit after the overpower protection of the constant current control unit, and enters the LED load unit after the overvoltage protection of the overvoltage protection unit. The LED load unit is connected to the LED constant current unit to realize constant current for the LED load unit, and the LED constant current unit is connected to the constant current control unit to realize overpower protection for the LED constant current unit. The utility model is mainly used for automobile taillights. This solution has a relatively high control cost and is more suitable for use in car taillights. It does not account for a significant proportion of the overall price of the car, but it is more expensive to use in mobility scooters or electric wheelchairs. Utility Model Content
[0004] The utility model provides a constant current taillight circuit for a low-cost electric scooter with simple and effective constant current control and low control cost in order to solve the problems that the taillight circuit of the existing scooter or electric wheelchair has no constant current control or adopts a relatively complex constant current control circuit, resulting in high circuit control cost.
[0005] The specific technical solution adopted by the utility model to solve the above technical problems is: a constant current taillight circuit for an electric scooter, characterized in that it includes a battery voltage interface terminal, a first diode, a second diode, a first resistor, a second resistor, a third diode, an NPN transistor and an LED taillight group, the battery voltage interface terminal adopts a 2P terminal structure and is used to be electrically connected to a 24V power supply battery, the anode of the first diode is electrically connected to the +24V terminal of the battery voltage interface terminal, the other terminal of the battery voltage interface terminal is electrically connected to the power supply battery ground, one end of the second resistor is electrically connected to the power supply battery ground, and one end of the second resistor is electrically connected to the power supply battery ground. The +24V terminal in the battery voltage interface terminal is electrically connected, the other end of the second resistor is electrically connected to the emitter of the NPN transistor, the cathode of the second diode after the cathode and anode of the first diode and the second diode are connected in series is electrically connected to the base of the NPN transistor, one end of the first resistor is electrically connected to the base of the PNP transistor, the other end of the first resistor is electrically connected to the anode of the third diode, the cathode of the third diode is electrically connected to the battery of the power supply ground, the collector of the PNP transistor is electrically connected to the anode of the headlight LED of the LED taillight group, and the cathode of the headlight LED of the LED taillight group is electrically connected to the anode of the third diode. Only one transistor, three diodes, and two resistors are used to effectively control the constant current control of the taillight, and the constant current control is simple and effective, and the control cost is low.
[0006] Preferably, the PNP transistor is a SOT-23 package size SMD amplifying transistor of model MMBT2907A, which can improve the storage temperature range of the transistor and reduce the manufacturing space size of the product.
[0007] Preferably, the first diode, the second diode and the third diode are M7F ultra-thin SMD rectifier diodes, which can reduce the product manufacturing space size and product manufacturing cost.
[0008] Preferably, the LED taillight group adopts two parallel LED light groups, each LED light group adopts 12 to 16 LED lights connected in series, so as to improve the simplicity, reliability and effectiveness of the constant current control of the left and right taillights.
[0009] The beneficial effects of the utility model are: the constant current lamp board design of the new electric scooter uses a low-cost rectifier diode voltage regulator control, and only one transistor, three diodes, and two resistors are used to effectively control the constant current control of the taillight. The constant current control is simple and effective, and the control cost is low. The circuit has strong surge resistance, good reliability, constant current can increase the life of the lamp beads, and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0011] Figure 1The utility model is a circuit structure schematic diagram of a constant current taillight circuit for an electric scooter. DETAILED DESCRIPTION
[0012] Figure 1 In the embodiment shown, a constant current taillight circuit for an electric scooter includes a battery voltage interface terminal CN1, a first diode D1, a second diode D2, a first resistor R1, a second resistor R2, a third diode D3, an NPN transistor Q1 and an LED taillight group. The battery voltage interface terminal CN1 adopts a 2P terminal structure and is used to be electrically connected to a 24V power supply battery. The anode of the first diode Q1 is electrically connected to the +24V terminal of the battery voltage interface terminal, the other terminal of the battery voltage interface terminal CN1 is electrically connected to the power supply battery ground GND, and one end of the second resistor R2 is electrically connected to the +24V terminal of the battery voltage interface terminal CN1. V terminal is electrically connected, the other end of the second resistor R2 is electrically connected to the emitter of the NPN transistor Q1, the cathode of the second diode D2 after the cathode and anode of the first diode D1 and the second diode D2 are connected in series in sequence is electrically connected to the base of the NPN transistor Q1, one end of the first resistor R1 is electrically connected to the base of the NPN transistor Q1, the other end of the first resistor R1 is electrically connected to the anode of the third diode D3, the cathode of the third diode D3 is electrically connected to the power battery ground GND, the collector of the PNP transistor Q1 is electrically connected to the anode of the headlight LED of the LED taillight group, and the cathode of the headlight LED of the LED taillight group is electrically connected to the anode of the third diode D3. The PNP transistor Q1 adopts a SOT-23 package size chip amplifier transistor of model MMBT2907A. The first diode D1, the second diode D2 and the third diode D3 all adopt the ultra-thin chip rectifier diode of model M7F. The LED taillight group uses two sets of parallel LED light groups, each set of LED light groups uses 12 LED lights in series (see Figure 1 As shown in FIG. 1 , LED1 to LED24 are connected in series. Of course, each LED light group can also be composed of 12 to 16 LED lights in series. Two parallel LED light groups can be used as warning and outline indicators at the left and right rear sides of a scooter or electric wheelchair.
[0013] Working principle: Battery voltage interface terminal CN1 is connected to battery voltage. When CN1 is powered, the positive electrode flows into the negative electrode GND (i.e., power battery ground) through the first diode D1, the second diode D2, the first resistor R1, and the third diode D3, so that the first diode D1 and the first diode D2 generate a 0.6*2V clamping voltage. At this moment, the PNP transistor Q1-PNP transistor terminal EB obtains a positive voltage, and the PNP transistor works in the amplification area and is turned on. At the same time, the collector current of the PNP transistor is controlled at I=0.6 / 24Ω through the LED1~LED24 light-emitting diodes connected in series behind, and the constant current is lit. This constant current circuit is particularly suitable for use in harsh environments where the battery voltage fluctuation range is large and the power battery voltage is often prone to surges. The yellow line (yellow) is designed to work only when the brake light signal is lit. When the light switch is turned on under the third diode D3, the headlight and taillight modes can be lit at the same time. Therefore, the role of the third diode D3 is to isolate the brake light signal.
[0014] The above content and structure describe the basic principle, main features and advantages of the utility model product, which should be understood by technicians in this industry. The above examples and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which are within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.
Claims
1. A constant current taillight circuit for an electric scooter, characterized in that: It includes a battery voltage interface terminal, a first diode, a second diode, a first resistor, a second resistor, a third diode, a PNP transistor and an LED taillight group. The battery voltage interface terminal adopts a 2P terminal structure and is used to be electrically connected to a 24V power supply battery. The anode of the first diode is electrically connected to the +24V terminal of the battery voltage interface terminal, and the other terminal of the battery voltage interface terminal is electrically connected to the power supply ground battery. One end of the second resistor is electrically connected to the +24V terminal of the battery voltage interface terminal, and the other end of the second resistor is electrically connected to the emitter of the NPN transistor. The cathode of the second diode after the cathode and anode of the first diode and the second diode are connected in series in sequence is electrically connected to the base of the NPN transistor. One end of the first resistor is electrically connected to the base of the NPN transistor, and the other end of the first resistor is electrically connected to the anode of the third diode. The cathode of the third diode is electrically connected to the power supply battery ground. The collector of the PNP transistor is electrically connected to the anode of the headlight LED of the LED taillight group, and the cathode of the headlight LED of the LED taillight group is electrically connected to the anode of the third diode.
2. The constant current taillight circuit for an electric scooter according to claim 1, characterized in that: The PNP transistor is a SOT-23 package size SMD transistor of model MMBT2907A.
3. The constant current taillight circuit for an electric scooter according to claim 1, characterized in that: The first diode, the second diode and the third diode are M7F ultra-thin chip rectifier diodes.
4. The constant current taillight circuit for an electric scooter according to claim 1, characterized in that: The LED taillight group adopts two parallel LED light groups, and each LED light group adopts 12 to 16 LED lights connected in series.