Use steps:1.Connect to power supply;2. rotary switch for 10second to switch Normal mode and Precise mode;3.Short rotary switch to set frequency and change value by rotating switch;4. rotary switch for 2second to set duty cycle; 5.Keep for 5second to lock set parameters; 6.Test;7. button 'ON/OFF' to turn on or off PWM output; 8.Remove power and connect load to use module. XY-KPWM signal generator is a device that provides electrical signals at a variety of frequencies, square wave, and output levels.It is used as a signal source or excitation source for testing.Widely used in production practice and technology. 1.With outer casing 2.LCD high definition display 3.Support UART 4.Support frequency adjustment 5.Support duty cycle adjustment 6.High precision detection 7.Support power-down memory function 8.1-Channel PWM output 9.Dual Work Mode 10.Knob supports lock function to avoid misoperation 11.Support enable output Parameters: 1.Product name: XY-KPWM PWM Signal Generator; 2.Model: XY-KPWM; 3.Work Voltage: DC 3.3V-30V; 4.Frequency range(Normal mode): 1Hz~150KHz; 5.Frequency range(Precise mode): 1Hz~15KHz; 6.Frequency accuracy: 2%; 7.Duty cycle accuracy: 1% at Normal mode; 8.Duty cycle accuracy: 0.1% at Precise mode; 9.Duty cycle range: 0.00%-100%; 10.Output Current: About 5-30mA; 11.Output amplitude: Same to input voltage; 12.Work Temperature: -40 Celsius~85 Celsius 13.Work Humidity: 0%~95%RH; Application: 1.Square wave signal generator, generating square wave signal for experimental development; 2.Used to generate a square wave signal that controls the motor driver; 3.Generate adjustable pulses for use by the MCU; 4.Dimmer; 5.Speed governor; colour: black Material: plastic size: 71 x 39mm Package Contents: 5 x Signal generator Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.