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Ebikes are more and more popular. Most ebike components are controlled by the controller of the electric bicycle, like the human brain or heart.
There is a microcomputer chip inside the controller, and it is said that it is the brain of the entire electric bicycle because of this chip. This chip's market retail price is only one or two dollars. In fact, it's very, very simple: it's a very large-scale integrated circuit itself, containing millions of transistor switching circuits. Since the 1980s, it has gradually become popular, and now there are many of him in almost every household appliance. The speed at which it has grown is astounding. A small single-chip microcomputer chip that retails for one or two dollars is also complete, equivalent to a micro computer. Although it is small in size and light in weight, it contains an arithmetic logic unit ALU, read-only memory ROM, and read-write memory RAM. Clock crystal oscillator CLOCK, interrupt system Interruption, input and output system IO, bus BUS, timer TIMER and so on. . . computer architecture. . . Hi! What are you talking about, it's too much! . . . Based on my years of professional study and work summary, I can explain what is the core principle of computer in one sentence. This is "if...then..."
The computer's so-called logic circuit composed of gate circuits, in the final analysis, is to solve if, then.
Take the brake of an electric bicycle, for example, when the brake is applied, a switch hidden inside the brake is triggered. This wire will pass a 5v voltage to a pin on the chip inside the controller. The microcontroller will think: If there is voltage on this pin, I will stop sending power to the motor, and it also wants to do it, cut off the power supply. Until when? That is, if, remember this, if the rider releases the brakes, normal power is restored. The braking process is over.
Most electric bicycles are not equipped with power aid brakes. Ebike stops the motor when braking, which will not affect the braking process and save some power. It's also very kind. By the way, the early cars did not have power assist brakes. The chips in the car are so important that the car factory will affect the overall car factory rate because of the shortage of chip supply.
We know that the battery voltage of electric bicycles is generally relatively high, 36V, 48V or 72V, of course, there are higher or lower voltages. Generally speaking, the higher the voltage, the better, it can directly provide power to the motor. However, microcomputer chips, circuit boards, various sensors, and lamps all use a relatively low voltage, 5V. This transistor is responsible for stepping down the 48V to 5V for use by these parts. The motors need 48V electricity, and they don't go directly through them either. In particular, most of the electric bicycle motors are brushless motors. Because compared with brushed motors, it is more reliable, power saving, low noise, small size, long life and no sparks. The brushes of brushed motors are prone to sparks and are prone to wear.
The other is the Mosfet field effect transistor, which is equivalent to a switch. 6 in total. 3X2 pieces. When the throttle handle is turned, the controller transmits the power of the battery to the motor in the form of pulses, and the frequency of the pulses is determined by the signal from the Hall coil.
There is also a sensor in the throttle handle, it is also a sensor that uses the electromagnetic effect, that is, the Hall effect. So there are 3 wires. The voltages are 0, 5, 0.80-3.80V, respectively.
The strength of the pulses the controller sends to the motor is controlled by this sensor. If it is 0-0.8V, no power is delivered. If it is 4V, the maximum power is delivered, and the power is delivered in proportion to the voltage value. At the same time, the frequency of the pulse is determined according to the position of the motor rotor sensed by the Hall coil, which coil or coils are energized.
It can be seen that the electrical part of the electric bicycle is a whole and the result of a teamwork.
The principle of power assist PAS is very similar, the only difference is the sensor. The sensor for the boost is not the distance of the magnet, but the speed. The LCD display central control panel, that is, the LCD display is not simple. This display also has a microcomputer chip inside, which also has very powerful functions and a very complex structure. Once again, it can be simply pretended to be a small robot living inside. This robot is amazing, very smart and dedicated. He can communicate with the dancing robot inside the controller on an if-then basis. For example, the two robots can cooperate to calculate the speed of the motor according to the Hall signal of the motor, and then calculate the speed of the riding according to the size of the tire. Then display this speed on the dashboard. Similarly, battery capacity, voltage, current, driving distance, etc. can be calculated and displayed on the screen.