Basically an electric motor is a mechanical device that switches electric energy into mechanical energy by passing an electric current through a wire loop contained within a magnetic field.

## # 电机分类

1.按工作电源种类划分：可分为直流电机和交流电机。

1)直流电动机按结构及工作原理可划分：无刷直流电动机和有刷直流电动机。

2)其中交流电机还可划分：单相电机和三相电机。

2.按结构和工作原理可划分：可分为直流电动机、异步电动机、同步电动机。

1)同步电机可划分：永磁同步电动机、磁阻同步电动机和磁滞同步电动机。

2)异步电机可划分：感应电动机和交流换向器电动机。

3.按起动与运行方式可划分：电容起动式单相异步电动机、电容运转式单相异步电动机、电容起动运转式单相异步电动机和分相式单相异步电动机。

### # 步进电机

A相与B相是不通的，用万用表很容易区分出来，至于各相的+-出线实际是不用考虑的，任意一相正负对调电机将反转。

### # Solenoid Lock

A solenoid, universally used in all types of motors from power door locks to starters and is simply a round coil of wire that's been insulated and used to create a magnetic field in the atmosphere of this current.

## # motor drive

• L9110
• L293D
• L298
• L298P
• L298N motor driver

## # 原理

PWM, or pulse width modulation is a technique which allows us to adjust the average value of the voltage that’s going to the electronic device by turning on and off the power at a fast rate. The average voltage depends on the duty cycle, or the amount of time the signal is ON versus the amount of time the signal is OFF in a single period of time. https://howtomechatronics.com/tutorials/arduino/arduino-dc-motor-control-tutorial-l298n-pwm-h-bridge/

## #

Arduino智能小车 https://www.hackster.io/goldscrew/arduino-obstacle-avoiding-robot-car-2wd-with-aa-battery-514b3c https://www.codemahal.com/2wd-robotic-car-arduino https://www.instructables.com/OSOYOO-2WD-Robot-Car-Starter-Kit/