Description: 【Application】: Ideal for school electronics training and DIY enthusiasts, this NE555 PWM speed controller kit offers hands on assembly experience and practical motor speed control 【Functionality】: Features an adjustable pulse generator circuit using NE555, allowing control of pulse frequency and width to regulate motor speed via a potentiometer 【Protection】: Built in components such as D1 prevent damage from reverse power connection, while D3 and C5 transistors by eliminating back EMF generated by the motor 【Stability】: Includes multiple capacitors for effective power filtering and interference reduction, ensuring stable reference voltage and reliable operation 【Material & Size】Constructed from PC,compact dimensions of 1.57inchx2.17inchx0.39inch make it easy to integrate into various electronic projects Size Chart: 4cmx5.5cmx1cm/1.57inchx2.17inchx0.39inch Package Includes: 1 set Pulse Width Speed Controller Note: Please allow slightly errors 1-2cm/0.39-0.79inch differences due to manual measurement.