CN206932169U - A kind of special DC DC12V20A converters of electric car - Google Patents

Abstract

A kind of special DC DC12V20A converters of electric car are the utility model is related to, are by the voltage of electromobile battery such as 48V, 60V, 64V, 72V etc. is converted into 12V, for the illuminator on electric car, instrument, loudspeaker, windshield wiper, lamplight pointing, fan, the 12V such as radio, reverse image low-voltage electrical appliances provide specified operating voltage.It can realize overcurrent protection, short-circuit protection, low-voltage variation, export the function of overpressure protection.

Description

A kind of special DC-DC12V20A converters of electric car

Technical field

It the utility model is related to electricity field, the special DC-DC12V20A converters of specially a kind of electric car.

Background technology

At present there is power output deficiency in electric car DC/DC power supply changeover devices on the market, and voltage regulation result is poor, load capacity Difference, it is fragile, easily burn the technical problems such as load.

Utility model content

In order to solve the above-mentioned technical problem, the utility model provides a kind of special DC-DC12V20A conversions of electric car Device, it is that the voltage of electromobile battery such as 48V, 60V, 64V, 72V etc. are converted into 12V, for the illuminator on electric car, instrument The 12V such as table, loudspeaker, windshield wiper, lamplight pointing, fan, radio, reverse image low-voltage electrical appliances provide specified work electricity Pressure.It can realize overcurrent protection, short-circuit protection, low-voltage variation, export the function of overpressure protection.

The utility model is achieved through the following technical solutions：A kind of special DC-DC12V20A converters of electric car, Including main circuit and control circuit, main circuit can realize energy storage and output overpressure protection, and control circuit plays surely in circuit Pressure acts on；The control circuit is made up of control chip, mu balanced circuit, oscillating circuit and impulse output circuit；The main circuit Including power input and power output end, and power input and output end are respectively connected with filter element；Input power is all the way The VCC pin of control chip are connected, is provided for chip and starts voltage, while stable+12V is exported by fast recovery diode and worked Voltage；NMOS tube, filter capacitor, Schottky diode, energy storage inductor and over-current detection resistance are accessed in another way；The filtering The positive pole of electric capacity and the drain electrode of NMOS tube are connected with the positive pole of input power；The source electrode of NMOS tube connects with over-current detection resistance Connect, and the ISENSE pin of control chip are connected by flowing detection resistance, while connect energy storage inductor and the pole of Schottky two respectively Pipe, and Schottky diode is connected with energy storage inductor, the other end of energy storage inductor connects output filter capacitor and transient state suppression respectively Diode processed；The mu balanced circuit is by Voltage stabilizing module, two regulating resistors, photo-coupler and load resistance composition, and with control The COMP pin of chip connect with VFB pin, and Voltage stabilizing module provides 2.5V reference voltages for VFB pin, when output voltage is too low or too high When, Voltage stabilizing module and two regulating resistor collective effects provide sampling voltage, pass through photo-coupler feedback and the VFB of control chip 2.5V reference voltages in pin control the conducting pulsewidth of NMOS tube more afterwards, so that output voltage stabilization, it is ensured that converter exists In the case of full load 20A, output voltage is still not less than 12V；The oscillating circuit is made up of resistance and electric capacity, and with control The RT-CT pin of chip are connected；The OUTPUT pin output pulse of the control chip, passes through resistance and the grid of NMOS tube respectively Be connected driving NMOS tube work, is powered to the load after output current is by filtered capacitor filtering after NMOS tube turns on；When When short circuit or the maximum allowed current more than setting occur for load, the ISENSE pin voltage of control chip rises, by controlling core The output pulse of piece internal adjustment OUTPUT pin, ends NMOS tube, protects NMOS tube not damage, and forms current foldback circuit； When NMOS tube is ended, energy storage inductor forms accumulator, and magnetic energy is changed into electric energy, and its polarity is left to bear the right side just, Schottky two Pole pipe turns on to form freewheeling circuit, continues to power to the load, and load is obtained smooth direct current；When output voltage is higher than setting Maximum allowable output voltage of adjuster when, Transient Suppression Diode reverse breakdown damage, formed output overpressure protection circuit；Make converter Output voltage is almost nil, thereby protects load and does not damage.

The NMOS tube, input power filter capacitor, Schottky diode are accessed by the way of at least two parallel connections Circuit.

The energy storage inductor is PQ32 type transformer type energy storage inductors.

The model YW/UTC3845E of the control chip.

The control chip is provided with eight pin：1st pin COMP, the 2nd pin VFB, the 3rd pin ISENSE, the 4th pin RT/CT, the 5th Pin GROUND, the 6th pin OUTPUT, the 7th pin VCC, the 8th pin VREF.

The beneficial effects of the utility model are：It is to change the voltage of electromobile battery such as 48V, 60V, 64V, 72V etc. Into 12V, for the illuminator on electric car, instrument, loudspeaker, windshield wiper, lamplight pointing, fan, radio, reverse image etc. 12V low-voltage electrical appliances provide specified operating voltage.Overcurrent protection, short-circuit protection, low-voltage variation, output superpressure guarantor can be realized The function of shield.

Brief description of the drawings

Fig. 1 is circuit diagram of the present utility model.

In figure, U1. control chips, U2. photo-couplers, D1. fast recovery diodes, D2. Transient Suppression Diodes, C1- C10. electric capacity, Q1, Q2.NMOS pipe, L1. transformer type energy storage inductors, Q3, Q4. Schottky diode, Q5. Voltage stabilizing modules, R1- R2. resistance, R3. over-current detection resistance, R4-R10 resistance, FU1. fuses.

Embodiment

As shown in Figure 1, the power input input 48-72V direct currents of main circuit, wherein connecting fuse FU1 all the way Afterwards by resistance R4 connection control chips U1 the 7th pin, provided for control chip U1 and start voltage, after resistance R4, connection Two electric capacity C2 and C4 in parallel, to enter control chip U1 current filtering, electric capacity C4 positive pole meets fast recovery diode D1 Negative electrode, fast recovery diode D1 anode connects the voltage of output+12V or so voltage, negative electrode output+12V or so, for control Chip U1 provides stable operating voltage；Fuse FU1 output end input power filter capacitor C9, C10 also in parallel with two Positive pole and NMOSQ1, Q2 drain electrode connection, power filtering capacitor C9, C10 negative pole ground connection；NMOSQ1, Q2 grid lead to Cross resistance R2 connection control chips U1 the 6th pin；The source electrode of NMOS tube Q1, Q2 is connected with over-current detection resistance R3, and passes through stream Detection resistance R3 connection control chips U1 the 3rd pin, while energy storage inductor L1 and Schottky diode Q3, Q4 are connected respectively Negative electrode, and Schottky diode Q3, Q4 and energy storage inductor L1 connections, the energy storage inductor L1 other end connect power supply output filter respectively Ripple electric capacity C8 positive pole and Transient Suppression Diode D2 negative electrode；Power supply output filter capacitor C8 negative pole and transient state suppresses two poles Pipe D2 plus earth；Control chip U1 the 3rd pin and the 8th pin are connected, and internal regulation resistance R6 is set on circuit；3rd pin and Form loop between 6th pin, series resistance R1 and electric capacity C1 on loop；Electricity is set between control chip U1 the 1st pin and the 2nd pin Hold C6, electric capacity C5 is set between the 2nd pin and the 3rd pin.

As shown in figure 1, the mu balanced circuit is by Voltage stabilizing module Q5, regulating resistor R7, R8, photo-coupler U2 and load resistance R10 is formed, and Voltage stabilizing module Q5 the 1st pin passes through the voltage output end of connection converter after regulating resistor R8 and R7 partial pressure, the 2nd pin Ground connection, the 3rd pin provide 2.5V reference voltages, photo-coupler U2 light by photo-coupler U2 for control chip U1 the 2nd pin The bipod of device connects control chip U1 the 1st pin and the 2nd pin respectively, and a pin of photophore is grounded by resistance R9, another pin point Not Lian Jie electric capacity C7 and Voltage stabilizing module Q5 the 3rd pin；When output voltage is too low or too high, Voltage stabilizing module Q5 and regulating resistor R7, R8 collective effect provide sampling voltage, pass through photo-coupler U2 feedbacks and the 2.5V benchmark electricity in control chip U1 the 2nd pin Pressure ratio controls the conducting pulsewidth of NMOS tube Q1, Q2 more afterwards, so that output voltage stabilization, it is ensured that converter is full load 20A's In the case of, output voltage is still not less than 12V；Resistance R5 and electric capacity C3 composition control chips U1 oscillating circuit, and with U1's 4th pin is connected；Control chip U1 the 6th pin output pulse, passes through resistance R1, R2 and the grid phase of NMOS tube Q1, Q2 respectively Connection driving NMOS tube Q1, Q2 work, output current is filtered backward by the filtered electric capacity C8 of L1 after NMOS tube Q1, Q2 conductings Load supplying；When short circuit or the maximum allowed current more than setting occur for load, control chip U1 the 3rd pin voltage rises, By the output pulse of the pin of control chip U1 internal adjustments the 6th, make NMOS tube Q1, Q2 cut-off, protection NMOS tube Q1, Q2 are not damaged It is bad, form output overpressure protection circuit；As NMOS tube Q1, when Q2 ends, energy storage inductor L1 forms accumulator, and magnetic energy is changed For electric energy, just, Schottky diode Q3, Q4 conducting is split into freewheeling circuit, continues to power to the load, makes load on its polarity left negative right side Obtain smooth direct current；When maximum allowable output voltage of adjuster of the output voltage higher than setting, Transient Suppression Diode D2 is reverse Punch through damage, make converter output voltage almost nil, thereby protect load and do not damage.

Claims (5)

1. A kind of 1. special DC-DC12V20A converters of electric car, it is characterised in that including main circuit and control circuit, main electricity Road can realize energy storage and output overpressure protection, and control circuit plays pressure stabilization function in circuit；The control circuit is by controlling Chip, mu balanced circuit, oscillating circuit and impulse output circuit composition；The main circuit includes power input and power supply exports End, and power input and output end are respectively connected with filter element；Input power connects the VCC pin of control chip all the way, is core Piece, which provides, starts voltage, while stable+12V operating voltages are exported by fast recovery diode；In another way access NMOS tube, Filter capacitor, Schottky diode, energy storage inductor and over-current detection resistance；The positive pole of the filter capacitor and the drain electrode of NMOS tube It is connected with the positive pole of input power；The source electrode of NMOS tube is connected with over-current detection resistance, and by flowing detection resistance connection control The ISENSE pin of coremaking piece, while energy storage inductor and Schottky diode are connected respectively, and Schottky diode and energy storage electricity Sense connection, the other end of energy storage inductor connect output filter capacitor and Transient Suppression Diode respectively；The mu balanced circuit is by steady Die block, two regulating resistors, photo-coupler and load resistance composition, and be connected with the COMP pin of control chip and VFB pin, surely Die block provides 2.5V reference voltages for VFB pin, and when output voltage is too low or too high, Voltage stabilizing module and two regulating resistors are total to Same-action provides sampling voltage, is fed back by photo-coupler with being controlled after the 2.5V reference voltages in the VFB pin of control chip The conducting pulsewidth of NMOS tube processed, so that output voltage stabilization, it is ensured that converter is in the case of full load 20A, output voltage Still it is not less than 12V；The oscillating circuit is made up of resistance and electric capacity, and is connected with the RT-CT pin of control chip；The control The OUTPUT pin output pulse of coremaking piece, be connected driving NMOS tube work by resistance with the grid of NMOS tube respectively, when Output current after filtered capacitor filtering by powering to the load after NMOS tube conducting；When short circuit occurs for load or more than setting During maximum allowed current, the ISENSE pin voltage of control chip rises, and passes through the output of control chip internal adjustment OUTPUT pin Pulse, end NMOS tube, protect NMOS tube not damage, form current foldback circuit；When NMOS tube is ended, energy storage inductor shape Into accumulator, magnetic energy is changed into electric energy, just, Schottky diode turns on to form freewheeling circuit, continues on its polarity left negative right side Power to the load, load is obtained smooth direct current；When maximum allowable output voltage of adjuster of the output voltage higher than setting, transient state Suppress diode reverse breakdown damage, form output overpressure protection circuit；Make converter output voltage almost nil, thereby protect Load does not damage.
2. 2. the special DC-DC12V20A converters of a kind of electric car according to claim 1, it is characterised in that described NMOS tube, input power filter capacitor, Schottky diode access circuit by the way of at least two parallel connections.
3. A kind of 3. special DC-DC12V20A converters of electric car according to claim 1, it is characterised in that the energy storage Inductance is PQ32 type transformer type energy storage inductors.
4. A kind of 4. special DC-DC12V20A converters of electric car according to claim 1, it is characterised in that the control The model YW/UTC3845E of chip.
5. 5. the special DC-DC12V20A converters of a kind of electric car according to claim 1 or 4, it is characterised in that described Control chip is provided with eight pin：1st pin COMP, the 2nd pin VFB, the 3rd pin ISENSE, the 4th pin RT/CT, the 5th pin GROUND, the 6th Pin OUTPUT, the 7th pin VCC, the 8th pin VREF.