简单的电子自行车电路[电动自行车]

This E-bike or electric bike circuit explained below can be used as the control circuit for constructing a homemade E-bike, with the help of a permanent magnet motor DC (PMDC motor), and aLi-Ion battery。

电动自行车基本上是自行车powered through a motor and a battery，这不需要手动踏板来操作自行车。在某些自行车中，还提供了手动踏板援助。

In this post we won't be discussing the entire wheel mechanism of the E-bike, rather we will only learn how to build the control circuit for the motor, and a finger press accelerator mechanism.

The whole idea is designed by me, with perfect understanding and brain simulation. However, the final design will need to be tested practically to confirm the proper working of the E bike circuit.

The idea is actually quite unconventional since this E-bike is supposed to operate without any pedal assistance. Instead the bike will depend entirely on the battery power. The battery could be charged externally through a suitable battery charger unit and grid power.

Basic Working

电子自行车项目基本上包括两个元素，一个PWM电动机控制器电路和一个手指按操作的油门或加速器电路。有关系统的基本工作详细信息的更多信息如下：

1. 一种PWM电动机控制器电路which responds to an external signal and proportionately varies the speed of the motor through a correspondingly varying PWM output.
2. 一个手指按加速器装置,包含一个勒D and an LDR, arranged one beside the other. The light from the LED is directed on a shaft and is reflected back towards the LED. The amount of light reflected from the shaft is determined by the proximity of the shaft towards the LED/LDR module, which is in turn determined by how much the shaft is depressed towards the LED/LDR arrangement.
3. 通过骑手按下连接的按钮来实现轴的按压。
4. 一种s the button is pressed deeper, the attached shaft moves closer to the LED/LDR module causing an increased amount of light to get reflected on the LED.
5. 随着LDR的光的增加，LDR电阻会降低，并将该信息转换为引起PWM宽度的信号，从PWM控制器增加。
6. The increase in the PWM width causes the E-bike motor speed and torque to increase, which in turn causes the speed of the E-bike accelerate.
7. 当加速器按钮的按下缓慢释放时，实现了相反的响应，这会导致PWM宽度减小并随后降低E自行车速度的加速度。

Finger Press Accelerator (Throttle)

手指媒体加速器的功能是为骑手提供他或她可以通过的设施increase or decrease the speedof the E-Bike motor through a corresponding pushing or releasing of the accelerator push button.

一种s explained above, the working of the finger pressed accelerator unit can be understood through the following points, and by referring to the following two diagrams.

可以看出上面的图，E自行车的手指推动器由弹簧载轴组成，该轴将其机械地连接到按钮。

We can also see anLED/LDRarrangement fixed parallel to the spring loaded shaft, such that the light from LED can fall on the inner surface of the shaft and get reflected towards the LED. The amount of light that can be reflected depends upon the proximity of the shaft toward the LED/LDR configuration.

由于spring tension, the shaft pushes the button outwards. When the push button is pressed with finger, it pushes the shaft inwards causing it move closer towards the LED/LDR module.

一种s the shaft is pushed harder, the shaft moves closer to the LED/LDR assembly causing proportionately greater amount of light to be reflected from the LED to theLDR。

这会导致LDR抗性降低。现在，如果按下按钮上的压力松开，则轴将从LED/LDR组件中移开，从而导致较低量的光量向LDR反射。LDR抗性现在增加。

LDR电阻值的上述增加和减小将发送到PWM控制器电路。

Here, the varying LDR resistance is appropriately converted to a signal which causes the PWM circuit to generate a correspondingly varying PWM signal output.

PWM Controller Circuit

The function of the PWM controller circuit is to sense the varying resistance of the LDR and convert it into a correspondingly changing PWM output. The PWM output is then fed to the E-bike motor for achieving the required speed control.

The circuit is built around a couple of IC 555, as shown in the following figure.

The working of the motor PWM controller circuit can be understood with the following points.

IC1 is configured as a simple555astable multivibratorcircuit which generates a 80 Hz rectangle wave output at its pin#3.

This 80 Hz frequency is sent to pin#2 of IC2 which is another IC 555 configured as a PWM generator.

在通过T1围绕R4/C3构建的RC积分器的帮助下，首先将80 Hz频率转换为80 Hz三角波。

This triangle wave is fed to pin#6 and pin#7 of IC2, which is subsequently compared with the voltage at pin#5 of IC2 to generate the corresponding PWMs at pin#3.

Thus, depending upon the potential level at pin#5, the output pulse at pin#3 of IC2 can vary from thinner to wider PWMs and vice versa.

IC2的引脚＃5的电势取决于T2的发射极电压。

T2 being configured like anemitter follower, produces an emitter voltage which is perfectly equivalent and in sync with its base voltage.

T2的基本电压取决于LDR的电阻，而LDR的电阻又由相邻的反射照明确定点灯。

How the light from the LED is reflected on the LDR is already explained earlier, under the "finger press accelerator" paragraphs.

Therefore, as explained before, when the shaft inside the finger press accelerator unit is pushed closer to the LED/LDR assembly, the light on the LDR decreases, causing higher amount of potential difference to be generated at the base of T2.

T2被配置为发射机跟随器，导致将这种不断增长的潜力发送到IC2的PIN＃5。

IC2现在将其转换为PIN＃3处增加的PWM。

恰恰相反，这就是PWM的减少，因为由于LDR上的照明减少，加速器轴缓慢释放时会发生。

How to Implement the E-Bike Circuit

实施拟议的电动自行车电路只是用自行车的后轮将PWM控制电动机连接起来。

The bicycle may have a pedal assist, however unlike conventional E-bikes, here the pedaling is not used for initiating the PWM circuit.

PWM电动机控制器只需按下加速器按钮即可启动。

However, if the bicycle is not first initiated through manual pedaling could cause a lot of strain on the motor and the battery, and the motor may be unable to push the bike forward.

Therefore, it is necessary to generate some initial kinetic energy on the bike through pedaling and only then push the accelerator switch, so that the motor can further assist the rider, allowing the pedaling to get easier.

Motor Specifications

The suggested motor for the above E-bike project is a 24V 250 watt permanent magnet DC motor (PMDC), as shown below:

由于电路是基于PWM的，因此建议的应用程序不需要附着的齿轮盒，并且电动机的初始化将为柔软而慢, rather than quick and abrupt.

Using Force Resistor for Throttle Controller

For the finger press accelerator unit, if you find the LED/LDR assembly mechanics a little cumbersome, you can easily replace it with a力传感电阻for getting the same results with higher efficiency, and in a more compact way. The modified design can be witnessed in the following diagram.

When pressure is applied on the force sensing resistor through finger pressing, the resistance of the force sensing resistor drops quite linearly, which is translated into PWMs with increasing width. The motor thus gains speed and acceleration.

当手指释放时，压力会从力传感电阻器中撤出，从而导致PWMS变得更窄。现在，电子自行车电动机的速度和加速度按比例脱离。

Since the force sensing resistor can be quite sensitive to pressure changes, it is recommended to use a thick rubber pad over the resistor, to blunt of the response a bit.

Battery Specifications

The battery recommended for the above E-bike circuit is a 24V 10 Ah Li-ion Battery. A 15 Ah rated battery can be even better than a 10 Ah battery. The example of the battery can be seen in the following image.

电池电压将需要通过low battery indicatorcircuit, or through a digital voltmeter or both.

一旦电池电压达到22以下，就必须将其从电子自行车上取出，并通过适当的额定方式在家中充电Li-Ion charger.

This concludes the construction details of our simple E-bike controller circuit.

If you have any specific questions related to the subject, please fee free to post them through comments below, I'll most happy to answer them.