This paper describes some domestic electric bicycle controller representative whole circuit, and that with the difference between other products and features. Circuit are listed in the mapping based on real income, the figure number is the author of the standard components. By introducing specific examples, to achieve the purpose of replication.
Electric Bicycle Controller
Popular electric bicycles, electric motorcycles most use DC motors, DC motor speed controller for many species. Electric vehicles is the core of pulse width modulation controller (PWM) device, and a sound controller, should also have battery voltage protection, motor overcurrent protection, power brakes, power display.
The size of the controller to power electric vehicles can be divided into high-power, medium power, low-power categories. Using a low-power electric bicycles, tricycles and electric motor freight to use the power and high power. Points from the line with the motor can be divided into brush, brushless two categories. About brushless controller, by the current technology and cost constraints, the failure rate is higher. The author believes that maintenance should be based brushless controller manufacturer based. The application of more brush controller, the controller can use the same kind of direct substitution or maintenance.
1. Instances of brush control
(1) a card with the power display, Shandong brush controller
Circuit block diagram shown in Figure 1.
1) circuit
Circuit diagram shown in Figure 2, the controller from the power supply circuit, PWM generation circuit, the motor drive circuit, battery discharge indication circuit, motor and battery over-discharge over-current protection circuit.
Power supply from the V3 (TL431), Q3 and other components, from a 36V battery through the series obtained after +12 V voltage regulator, to the control circuitry to regulate the VR6 +12 V power supply can be calibrated.
PWM circuit to pulse width modulator TL494 at the core. R3, C4 and the internal oscillation circuit, frequency of approximately 12kHz.
H is a high-to low-type speed control switch to the Hall, from release to tighten, its output voltage can be obtained 4V-1V. The voltage is applied to the ? TL494 feet, compared with pin voltage, in the foot get-width-modulated pulse ?. Pin voltage is lower ?, ? pin pulse width modulated output low part of the wider, the higher the motor speed, zero speed potentiometer VR2 to adjust, adjust VR2 to turn to release the motor stopped another point.
Motor drive circuit from the Q1, Q2, Q4 and other components. Permanent magnet motor MOTOR DC brush motors. TL494's ? pin pulse width modulated output, driven by the inverting amplifier Q1 VDMOS tube Q2. TL494's ? pin low pulse width modulated output part of the wider, the longer the Q2 turn, the higher the motor speed. Motor freewheeling diode D1 is to prevent the Q2 breakdown. TL494's ? pin output low, Q1, D2 turns on, Q4 closing, Q2 conduction; TL494's ? pin output goes high, Q1, D2 deadline, Q4 turns on, Q2 gate charge promptly discharge, accelerated The closing process of Q2, Q2 to reduce the temperature has a very important role.
Indicates the battery discharge circuit composed of four by the LM324 comparator, 12V by the R24, VR1, VR4, VR3, VR5, R21 to form four different partial pressure were added to the four comparison reference voltage inverting side. Battery voltage by R23 and R22 divider comparator added to each end of the same phase, the proportional voltage and battery voltage. VA = VB * R22 / (R22 + R23). When the battery voltage is not lower than 38V when, LED1, LED2, LED3 are lit; when the battery voltage is below 38V when, LED3 off; when the battery voltage is below 35V when, LED2 off; when the battery voltage is below 33V when, LED1 off , and you should charge the battery. Adjust VR1, VR4, VR3 can be set LED3, LED2, LED1 off the voltage. LED4 used as a power indicator, LED5 instructions for controller output voltage cut off.
Battery discharge protection when the battery discharges to 31.5V time. LM324's output low ? feet, transistor Q5 turns on, about 5V voltage is applied to the control TL494 dead end ? feet. The pin potential = 3.5V, it will force TL494 pulse width modulated output tube internal deadline, so that the transistor Q1, Q2 off, the motor stops running, stop the battery discharge into the battery protection status. At this point LED5 lit, indicates that state. VR5 point for setting battery protection voltage.
Motor over-current protection for the motor current sampling resistor R30, when over-current, the sampling voltage added by the R14's ? TL494 feet. When ? ? feet higher than the potential of the foot when the potential, TL494 high output internal op amp 2, forcing the TL494 Pulse Width Modulated output tube within the deadline, so that Q1, Q2 off, the motor stops running, thereby protecting the motor.
Brake protection when the brakes when braking, KEY2 TL494 connected to .5 V voltage is applied to control terminals ? dead leg, forcing the TL494 Pulse Width Modulated output tube within the deadline, so that Q1, Q2 off, the motor stops running, the implementation of the brake protection.
2) Debugging
Zero speed governor circuit debug: speed switch to full release. Adjust VR2 so that the motor is stopped and then had a little adjustment to ensure a reliable zero-speed. Brake adjustment: turn the rotation speed, the motor rotation. Brake switch is closed at this time KEY2, Q2 goes low gate immediately 0V. Over-current protection debug: turn the rotation speed, Q2 gate is high 12V. At this point in the source on the ground with about 0.8V voltage, the gate should soon become low.
Indicates the battery discharge circuit with adjustable power supply instead of batteries. Voltage of 38V, the regulator VR1, just off the LED3; voltage of 35V, the regulator VR2, just off the LED2; voltage of 33V, the regulator VR3, just off the LED1; voltage of 31V, the regulator VR5, just to make LED5 light, when the ? TL494 5V feet high should be about to enter the battery voltage protected. Through this setting, only LED1 is lit, the voltage is 33V-34V, to charge the battery in time, but off to the LED5 LED1 lit this time, the battery can maintain the running, but LED5 lit into the under-voltage protected . You should note, then, the motor stopped due to switch to the battery voltage recovery, protection lifted, and return to work. So repeatedly protection - work - protection of the results will damage the battery and control
Controller, therefore, should avoid this situation.
(2) Shanghai Wei was the controller card
With LM324, LM393 and LM339 brush controller produced a very high reliability, that is, more number of devices. The controller produced only one LM339 brush controller. LM339 manufactured by another piece of power display section. Display section shown in Figure 3, the circuit shown in Figure 4.
Shanghai Weixing speed of the controller to use the photoelectric transfer rate. Because the north dry, sandy dirt and impact of the photoelectric switch to the use of speed. Practice has proved that speed can turn to use the Hall to replace it. Specific methods shown in Figure 5.
Speed optical switch to turn the key to the Hall velocity has two points: First, install +5 V power supply; the second is based on the original speed of the signal changes of the signal output point, choose the appropriate speed control switch signal changes to the Hall.
The brush controller PWM circuit as the core, in front of the triangular wave generator, battery voltage detection, motor current detection; behind the driver, the power switch. Each part is independent. Check debugging is more convenient. Triangle wave generator by the IC2A, R17, C5, D2, R9, R10 etc. Schmitt oscillator to generate the C5 triangle. Pulse width modulator is IC2B, one of its input feet from C5 on the triangle wave, the input of the second ? feet, speed of transfer from the (J1) foot speed signal. Feet from the IC2B pulse width modulated output, sending complementary push-pull amplifier. Complementary push-pull driven by the T3, T4 composition, high pulse arrival T4 on the conduction tube tube NPN, 12V added to the power tube T1, T2 of the gate, T1, T2 turn; pulse low arrival, on the tube NPN tube T4 closed. PNP under the control tube T2 turns on, the T1, T2 gate charge quickly let go, T1, T2 cutoff. Battery voltage protection voltage comparator composed by the IC2C, when the battery voltage is lower than 31.5V, it's feet into the low potential, the equivalent of R13 input end of the ground, will be transferred to the speed signal drops close to zero volts. So IC2B feet was low, T4 end, T3 conduction; T1, T2 cutoff. Over-current protection voltage comparator composed by the IC2D, when over current. R4 right end of the potential low. IC2D ? feet added by R5, comparator, flip feet into a low potential, the same is equivalent to the input side of R13 to ground. Will be transferred to the speed signal drops close to zero volts, the T1, T2 cutoff.
(3), Mianyang, Sichuan Province in the middle of a power brush controller card
The controller brushless ASIC, MC33035 core production of brush control.
Controller circuit diagram shown in Figure 6, the brake controller is characterized by a three-pronged approach, the specific works as follows:
Brake circuit mainly by the J, Q3, Q6 and so on. Relay normally open contacts in series circuit in the motor power supply, +24 V through R29, D8 to provide base current to Q3, Q3 turns on, J was electric pull, normally open contacts closed, the motor is energized.
1) When the brake, the left and right brake switch is closed, +15 V through R25, R21 provides base current to Q6, Q6 turns on, the collector potential decreased, D4 conduction, so that D8 end, Q3 loss of base current and cut-off , J lost power, normally open contacts off, the motor lost power to stop turning.
2) Q6 turns on, the collector potential decreases, D5 also turn reduces the potential U1 of feet. The shutdown pin low PWM output.
3) Q6 turns on, the collector potential decreases, D6 are conducting, whether at low speed or high-speed switch to the position, will be transferred to the Hall governor speed signal-to-ground short-circuit and reduce the foot of the signal sent to U1 voltage.
Undervoltage protection circuit by the voltage detection and single-ended flip-flop U2B component U3. Both hands down by the output U1 of Q4 feet off the output of U1. Transferred to the output voltage detection U2C U3 force sent to single-ended trigger for speed reduction side foot work.
(4) Beijing features a brand brush with anti-Speed Controller
Circuit shown in Figure Anti-Speed function relies on the positive in series between the motor and the power relay normally closed contact J J achieved. One of the following two cases, will cause the relay is energized, disconnect the electrical power: First, motor over-current; the second is the speed at zero speed switch to position, VDMOS drain D is low potential (switch breakdown) . Motor over-current, current sense resistor R1 lower voltage goes low, current sense pin goes low IC1A of foot into a high potential, the D5 to T7, T8 turn, J is energized, normally closed contacts open.
When the rate of transfer to the zero speed position, PWM IC2's pin low potential, D3 close, T6 off, its collector high potential. Case: If the power switch did not breakdown the VDMOS drain D is high potential, conduction through R6 to T6, the low collector potential, the diode D4 is working with the door, the T5, T6 is only a high potential of the collector , diode D4 close, T7, T8 end, J not electricity, the normally closed contact is closed. so that the motor is controlled by T1, T2; another situation: If the power switch is the breakdown, the drain D, VDMOS low potential, the R6 to T5 end, the collector of high potential, the diode D4 is working with the door, the T5, T6 are the high potential of the collector, diode D4 conduction; T7, T8 turn, J is energized, its normally closed contact off, the motor loss of power to achieve protection against runaway.
When the speed is not zero speed switch to the position, PWM IC2's pin is a string of positive pulse ?, the integral circuit R20, C7 points, C7 potential rise, D3 conduction, T6 conduction. Its low collector potential, the diode D4 is working with the door, regardless of T5 collector potential is high or low, the diode D4 are closing, T7, T8 closed. J no electricity, the normally closed contacts so that the motor is energized. Ensure the normal power switch conduction time VDMOS drain D is low potential, the electrical flow can be controlled so long as the motor rotation.