Electronic horn with electrical waterproof function for electric bicycle

Abstract

The application provides an electronic horn with electrical waterproof function for electric bicycle, wherein a single-chip microcomputer collects a K1 switch state signal under the condition that the power supply is powered on after the whole vehicle is locked, and the single-chip microcomputer controls NMOS switch to drive the transformer primary coil switch energy storage according to the collected signal, and the transformer secondary side drives the vibration energy release of the horn after voltage conversion. The application has the beneficial effects that: the electronic horn with electrical waterproof function for electric bicycle separates the power supply and control signal of the electronic horn to achieve the waterproof function, the switch signal of the horn is directly collected by the single-chip microcomputer through a current-limiting resistor and a triode, and the switch signal has the waterproof ability through reasonable parameter matching, so that the horn does not appear false ringing or failure after raining, and the user can have stable and reliable use experience.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of circuit, in particular to an electronic horn with electrical waterproof function for electric bicycle. BACKGROUND

[0002] Electric bicycle is a very convenient and green product using new energy, and its use scene is becoming more and more popular. The horn device of electric bicycle is an essential electrical component for safe use.

[0003] At present, most of the horn devices of electric bicycle are two-wire electronic horn or iron horn, and the control mode is generally realized by directly controlling the power on-off of the horn. The ordinary electronic horn adopts H-bridge mode to drive the piezoelectric ceramic sheet to vibrate and sound, and the driving voltage of the piezoelectric ceramic sheet is equal to the power voltage. The sound size is linearly related to the driving voltage, and the higher the voltage, the louder the sound, and the lower the voltage, the smaller the sound. Therefore, the sound size is very different when the electronic horn works in the full battery and depleted state. The sound quality of the piezoelectric ceramic vibration sheet is generally sharp and harsh, and lacks low-frequency and thick sound quality.

[0004] The sound of iron horn is loud and deep without being harsh, but the driving current required by the electromagnetic vibration principle of iron horn is large, and the electromagnetic interference is large, which will have a great impact on other electrical components of the vehicle, especially the communication system. Often, when the horn sounds, other electrical components appear abnormal, such as headlight flickering, instrument display abnormality, networking function abnormality and other abnormal phenomena, and even cause danger during riding.

[0005] The direct control of the power on-off of the horn is adopted. The horn power is battery power (mostly 48V / 60V / 72V or DC-DC converter provides 12V power), which causes the voltage difference of the closed and broken switch of the button switch, and the instantaneous current is large, so the performance requirement of the button switch is high. In the long-term use, the switch is easy to be damaged by electric shock, oxidation and other physical damage, causing the switch to malfunction, burn out or burn down. After raining outdoors, the error sound and malfunction occur, which makes people suffer. SUMMARY

[0006] Therefore, the present application aims to provide an electronic horn with electrical waterproof function for electric bicycle to at least solve at least one problem in the background art.

[0007] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0008] An electronic horn with electrical waterproof function for electric bicycle, the single-chip microcomputer collects the switch state signal of K1 under the condition of the power on of the whole vehicle lock, and the single-chip microcomputer controls the NMOS switch to drive the transformer primary coil switch energy storage according to the collected signal, and the transformer secondary drives the vibration energy release of the horn after step-up conversion.

[0009] Further, the power supply is connected to the primary coil of the transformer through the power supply V+ of the whole vehicle, and the other end of the primary coil is connected to the drain of the NMOS switch tube Q1, the source of the Q1 is connected to the GND, the resistor R9 is connected between the gate and the source of the Q1, the gate of the Q1 is connected to the first pin of the single-chip microcomputer U1 through the resistor R10, and the third and fourth pins of the secondary end of the transformer are connected to the piezoelectric ceramic buzzer HTL.

[0010] Further, the power supply is connected to the primary coil of the transformer through the power supply V+ of the whole vehicle, and the other end of the primary coil is connected to the drain of the NMOS switch tube Q1, the source of the Q1 is connected to the GND, the resistor R9 is connected between the gate and the source of the Q1, the gate of the Q1 is connected to the first pin of the single-chip microcomputer U1 through the resistor R10, and the third and fourth pins of the secondary end of the transformer are connected to the piezoelectric ceramic buzzer HTL.

[0011] Further, the power supply is connected to the primary coil of the transformer through the power supply V+ of the whole vehicle, and the other end of the primary coil is connected to the drain of the NMOS switch tube Q1, the source of the Q1 is connected to the GND, the resistor R9 is connected between the gate and the source of the Q1, the gate of the Q1 is connected to the first pin of the single-chip microcomputer U1 through the resistor R10, and the third and fourth pins of the secondary end of the transformer are connected to the piezoelectric ceramic buzzer HTL.

[0012] Further, the first end of the safety current-limiting resistor R1 is connected to the negative electrode of the diode D1, and the second end is connected to the primary coil end, and the safety current-limiting resistor R1 is used to ensure the safety of the whole circuit in the case of abnormal current increase caused by the whole circuit,

[0013] Further, the RCD absorption circuit is connected in parallel across the primary coil of the transformer, including the resistor R5, the capacitor C1 and the diode D2, the negative electrode of the diode D2 is connected to the first end of the resistor R5 and the first end of the capacitor C1, and the second end of the resistor R5 and the second end of the capacitor C1 are connected to the circuit between the resistor R1 and the primary coil 1.

[0014] Further, the horn button K1 is connected to the GND at one end, and the other end of the K1 is connected to the base of the NPN triode Q2 through the current-limiting resistor R6, the resistor R2 is connected in series with the resistor R7, and then connected in parallel across the resistor R3, the first end of the resistor R6 is connected to the middle connection point of the resistor R2 and the resistor R7, the emitter of the triode Q2 is connected to the GND, and the collector of the triode Q2 is connected to the fourth pin of the single-chip microcomputer U1 as the acquisition of the switching signal, and the resistors R2 and R7 function as the pull-up resistor of the base of the Q2 to ensure that the Q2 is in the conducting state after power-on, and the Q2 is in the cut-off state after the switch K1 is pressed down.

[0015] Further, the second pin of the single-chip microcomputer U1 is GND, and the fifth pin is connected with a +5V power supply, when the U1 detects that the switch K1 is closed, the high and low signals of the third pin voltage are collected, the duty cycle of the sound source is adjusted according to the high and low signals of the voltage obtained by testing, and the adjusted sound source switching waveform is output from the first pin and controls the NMOS tube Q1 switching through the current limiting resistor R10, the Q1 is turned on to store energy in the transformer T1, and the energy is released during the Q1 closing period.

[0016] Compared with the prior art, the electronic horn for electric bicycles with the electrical waterproof function has the following beneficial effects:

[0017] (1) The electronic horn for electric bicycles with the electrical waterproof function, by the resistance, the voltage stabilizing diode and the capacitor, realizes a DC-DC low-cost voltage reduction scheme to supply power for the low-power single-chip microcomputer;

[0018] (2) The electronic horn for electric bicycles with the electrical waterproof function, the single-chip microcomputer uses the waveform of the analog sound source to control the NMOS switching to drive the transformer primary coil switching to store energy, the transformer secondary is converted through voltage boosting to drive the piezoelectric ceramic buzzer to vibrate to release energy, realizes the voltage boosting principle to increase the driving voltage of the piezoelectric ceramic buzzer to increase the vibration amplitude to achieve the purpose of increasing the sound loudness, and the transformer adopts the DCM mode to meet the design that the volume changes little in a wide power supply voltage range;

[0019] (3) The electronic horn for electric bicycles with the electrical waterproof function, in order to achieve the waterproof function of the horn switch, the power supply and the control signal of the electronic horn are connected separately to realize the waterproof function, the switching signal of the horn is collected by the single-chip microcomputer through the current limiting resistor and the triode, the switching signal has the waterproof ability through reasonable parameter matching, and the horn does not appear false ringing or failure after raining, and the user can have a stable and reliable use experience;

[0020] (4) The electronic horn for electric bicycles with the electrical waterproof function, the sound is controlled by the single-chip microcomputer, a plurality of sound required driving waveforms can be stored according to needs, a plurality of sound switching can be realized according to needs, and the user can have the opportunity to select a plurality of sound sources;

[0021] (5) The electronic horn with the electrical waterproof function for the electric bicycle has the functions of low working energy consumption, loud sound, long service life, wide application range, small size, small external interference, programmable sound modification, integrated multi-sound source, low cost, power reverse connection protection, overcurrent protection, and waterproof protection of the horn switch from false triggering. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application, and are incorporated herein for explanation of the present application and are not intended to constitute an improper limitation of the present application. In the drawings:

[0023] Figure 1 The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application, and are incorporated herein for explanation of the present application and are not intended to constitute an improper limitation of the present application. In the drawings:

[0024] Figure 2 The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application, and are incorporated herein for explanation of the present application and are not intended to constitute an improper limitation of the present application. In the drawings: DETAILED DESCRIPTION

[0025] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0026] The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] The present application uses the power supply of the electric bicycle switch lock to avoid the problem of long-term power consumption when not in use, and realizes a DC-DC low-cost step-down scheme for the power supply of the low-power single-chip microcomputer through resistors, zener diodes and capacitors.

[0028] The single-chip microcomputer uses the waveform of the analog sound source to control the NMOS switch to drive the transformer primary coil switch energy storage, and the transformer secondary is converted through step-up conversion to drive the piezoelectric ceramic buzzer to vibrate and release energy, realizing the purpose of increasing the driving voltage of the piezoelectric ceramic buzzer to increase the vibration amplitude and improve the sound loudness, and the transformer adopts the DCM mode to meet the design of little change in volume in a wide range of power supply voltage.

[0029] In order to achieve the waterproof function of the horn switch, the power supply and control signal of the electronic horn are connected separately, the switch signal of the horn is collected by the single-chip microcomputer through the current limiting resistor and the triode, and through reasonable parameter matching, the switch signal has waterproof capability, and the horn does not appear false ringing or failure after raining, etc.

[0030] The sound of the application is controlled by the single-chip microcomputer, and the required drive waveform of multiple sounds can be stored according to needs, and multiple sound switching can be realized according to needs, so as to provide users with multiple sound source selection opportunities.

[0031] The power supply of the application adopts the power supply of the battery of the electric bicycle, is compatible with the battery voltage platform of 36V to 72V, the working current is less than 100mA, and the sound size reaches 100dB (parallel height 2m distance test). The application has the characteristics of low working energy consumption, large sound, long service life, wide application range, small size, small external interference, programmable sound modification, integrated multiple sound sources, low cost, and the protection functions of power supply anti-reverse connection protection, overcurrent protection, and horn switch waterproof false triggering, which are very practical and have good popularization function and performance.

[0032] As shown in Figure 1 The power supply is connected to the anode of the 4.7V zener diode ZD1 through the anti-reverse diode D1 and the fuse resistor R1 in turn, the cathode of ZD1 is grounded, the filter energy storage capacitor C2 is connected in parallel between ZD1 to form the +5V power supply of the low-voltage system, one way is connected in series through R4 and R8 to GND, and the voltage signal is collected through the 3rd pin of the single-chip microcomputer after being divided by R4 and R8, and the filter capacitor C3 is connected in parallel between R8; the other way is connected to the 1st pin of the primary coil of the transformer, the 2nd pin of the primary coil of the transformer is connected to the drain of the NMOS switch tube Q1, the source of Q1 is connected to GND, R9 is connected in parallel between the gate and the source of Q1, and the gate of Q1 is connected to the 1st pin of the single-chip microcomputer U1 through the resistor R10. The 3rd and 4th pins of the secondary end of the transformer are connected to the piezoelectric ceramic buzzer HTL.

[0033] K1 is an external horn button, one end is connected to GND, the other end of K1 passes through current limiting resistor R6 to reach the base of NPN triode Q2, resistor R2 is connected in series with R7 and is connected to both ends of resistor R3, the middle connection point of resistor R2 and resistor R7 is connected to the first end of resistor R6, the emitter of triode Q2 is connected to GND, the collector of triode Q2 is connected to the fourth pin of single-chip microcomputer U1 as a collection of switch signal, R2 and R7 function as pull-up resistors of Q2 base, ensuring that Q2 is in a conductive state after power-on, and Q2 is in an off state after the switch K1 is pressed and pulled down, and the single-chip microcomputer U1 can accurately collect the state of the switch K1 after setting the internal pull-up resistor through the fourth pin, and the switch K1 is a normally open self-resetting switch, and when the switch is not pressed, the triode Q2 base is pulled up to a high level due to the voltage division of resistors R2 and R7, triggering a current to flow from V+ through D1, R1, R2 to the base of Q2, to the emitter of Q2, so that Q2 is turned on, and the fourth pin of the single-chip microcomputer U1 collects a low-level signal. If the switch K1 is pressed, the R6 connection at the switch K1 is low, the triode Q2 is off, and the single-chip microcomputer built-in pull-up resistor tests to a high-level signal, completing the collection of the switch signal.

[0034] The second pin of the single-chip microcomputer U1 is GND, and the fifth pin is a power supply pin connected to a +5V power supply, when U1 detects that the switch K1 is closed, the voltage high-low signal of the third pin is collected, and the voltage high-low signal obtained by testing is used to adjust the duty cycle of the sound source, and the adjusted sound source switching waveform is output from the first pin to control the NMOS tube Q1 switching through the current limiting resistor R10, and Q1 is turned on to store energy in the transformer T1, and Q1 is turned off to release energy. In order to ensure that the sound is the same size under different power supply voltages, the software sets an adjustment coefficient to adjust the duty cycle of the MOS tube switching.

[0035] The switch waterproof function of the application is realized by using a small signal pull-up amplification circuit of the switch K1, and after the switch is immersed in water or rained on, due to the effect of charged particles in water, an equivalent resistance effect is formed between the two ends of the switch, the size of the equivalent resistance is related to the concentration of charged particles in the water solution, the distance and area between the switch, and through test verification, the equivalent resistance is usually greater than 5k ohms, and we determine through equivalent calculation that R2 can ensure that triode Q2 can be turned on under the action of a pull-down resistance of 5k ohms at the lowest power supply voltage, so as to achieve the waterproof function, and even if the switch is immersed in water or soaked in water, the single-chip microcomputer will not collect incorrect switch signals to drive the piezoelectric buzzer to sound.

[0036] The diode D1 in the circuit plays a role of preventing reverse connection, so that the electrical components will not be damaged even if the power supply is reversed, and also plays a role of isolation and anti-interference, preventing the reverse peak voltage of the transformer T1 from flowing to the power supply V+ side when the switch tube is closed, affecting the normal work of other electrical components. Even if the switch K1 is mistakenly connected to the power supply V+, the resistance value selected by R6 can be large, so that the electrical components will not be damaged, and the foolproof protection of the interface can be good.

[0037] The piezoelectric ceramic buzzer driving circuit in the circuit uses a transformer with electrical isolation to achieve good isolation protection function. The primary coil is terminated with a fuse current limiting resistor R1 to ensure safety in case of abnormal increase of current in the overall circuit. The RCD absorption circuit is connected in parallel across the transformer primary coil to protect the safety of the NMOS tube Q1. When Q1 is cut off, the reverse peak voltage is absorbed to avoid the breakdown caused by the superposition of the high reverse voltage and the power supply voltage exceeding the withstand voltage limit of the switch tube NMOS, thereby ensuring the normal operation of the circuit.

[0038] Figure 1 3P-1 is the first pin of the terminal, which is the whole vehicle lock rear power input terminal, 3P-2 is the input terminal for connecting the external horn switch K1 signal, and 3P-3 is the third pin of the terminal, which is the ground pin.

[0039] When the horn switch K1 is closed at the power-on moment, the operation of switching the sound source is performed.

[0040] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application.

[0041] The above is only the preferred embodiment of the present application, and does not limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An electronic horn for electric bicycle with electrical waterproof function, characterized in that: The single-chip microcomputer collects the switch state signal of K1 under the condition of the power supply after the whole vehicle is locked, and controls the NMOS switch to drive the transformer primary coil switch energy storage according to the collected signal, and the secondary side of the transformer drives the horn vibration release energy after voltage conversion. The power supply and control signal of the horn are connected separately. The power supply is connected in series through R4 and R8 to GND from the power supply V+ after the whole vehicle is locked, and is connected to the third pin of the single-chip microcomputer to collect the voltage signal after being divided by R4 and R8, and the filter capacitor C3 is connected across R8. It includes an external horn button K1, one end of which is connected to GND, and the other end reaches the base of NPN triode Q2 through current-limiting resistor R6, resistor R2 is connected in series with R7 and then connected across resistor R3, the middle connection point of resistor R2 and resistor R7 is connected to the first end of resistor R6, the emitter of triode Q2 is connected to GND, and the collector of triode Q2 is connected to the fourth pin of single-chip microcomputer U1 as a switch signal collector, R2 and R7 serve as pull-up resistors for the base of Q2 to ensure that Q2 is in a conductive state after being powered on, and Q2 is in a cut-off state after the switch K1 is pressed down. The power supply is connected to the 1 pin of the transformer primary coil from the other way of the power supply V+ after the whole vehicle is locked, the 2 pin of the transformer primary coil is connected to the drain of NMOS switch tube Q1, the source of Q1 is connected to GND, R9 is connected in parallel between the gate and source of Q1, the gate of Q1 is connected to the first pin of single-chip microcomputer U1 through resistor R10, and the 3 and 4 pins of the secondary side of the transformer are connected in parallel to piezoelectric ceramic buzzer HTL.

2. The electric bicycle electronic horn with electrical waterproof function according to claim 1, characterized in that: The power supply is connected in series through anti-reverse diode D1 and safety resistor R1 from the power supply V+ after the whole vehicle is locked, then flows through current-limiting resistor R3 to the anode of 4.7V zener diode ZD1, the cathode of ZD1 is grounded, and filter energy storage capacitor C2 is connected in parallel across ZD1 to form a +5V power supply for the low-voltage system.

3. The electric bicycle electronic horn with electrical waterproof function according to claim 1, characterized in that: The first end of safety current-limiting resistor R1 is connected to the negative electrode of diode D1, and the second end is connected to the primary coil end, which is used to ensure safety in the case of abnormal current increase caused by the overall circuit.

4. The electric bicycle electronic horn with electrical waterproof function according to claim 1, characterized in that: An RCD absorption circuit is connected in parallel across the transformer primary coil, including resistor R5, capacitor C1 and diode D2, the negative electrode of diode D2 is connected to the first end of resistor R5 and the first end of capacitor C1, the second end of resistor R5 and the second end of capacitor C1 are connected to the circuit between resistor R1 and the 1 pin of the primary coil.

5. The electric bicycle electronic horn with electrical waterproof function according to claim 1, characterized in that: The second pin of single-chip microcomputer U1 is GND, and the fifth pin is the power supply pin connected to +5V power supply, when U1 detects that the switch K1 is closed, the high and low voltage signals of the third pin are collected, the duty cycle of the sound source is adjusted according to the tested voltage high and low signals, and the adjusted sound source switching waveform is output from the first pin to control the NMOS tube Q1 switch through current-limiting resistor R10, Q1 is turned on to allow the transformer T1 to store energy, and Q1 is turned off to release energy.

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