This NE555 square wave pulse generator module can be used to produce square wave signals for experimental development or in applications such as driving stepper motors, and as an adjustable pulse generator for microcontroller (MCU) applications.
Features an NE555 timer chip configured in four frequency ranges, 1Hz to 50Hz, 50Hz to 1kHz, 1kHz to 10kHz and 10kHz to 200kHz all adjustable with onboard jumpers and two trim-pots to adjust the output frequency and the duty cycle.
Input voltage to the module (VCC) is variable from 5V to 15V DC and draws approximately 15mA at 5v (35mA at 12v) with an output amplitude of 4.2V peak-to-peak to 11.4V peak-to-peak based on the supply voltage.
An indicator LED illuminates on a low-level output and flashes relative to the output frequency. At higher frequencies, the LED will appear to be on solid and without a visible flash.
Features & Specifications:
Size: 31mm * 22mm
Main chip: NE555
Input Voltage (VCC): 5V-15VDC
Input current:~100MA
Output amplitude: 4.2V V-PP to 11.4V V-PP. (Varries with VCC voltage)
Maximum output current: 15MA (VCC=5V, V-PP greater than 50%), 35MA (VCC=12V, V-PP greater than 50%)
Output LED indicator (low level, LED is on, high level, LED is off; LED flashes with frequency
The output frequency is continuously adjustable using the onboard jumpers and potentiometers. Jumper settings are:
1Hz ~ 50Hz
50Hz ~ 1kHz
1KHz ~ 10kHz
10kHz ~ 200kHz
The output duty cycle can fine-tuned using the onboard potentiometers. Duty cycle and frequency are not separately adjustable; adjusting the duty cycle will change the frequency.
Package Includes:
1X NE555 Duty Cycle Adjustable Pulse Frequency Square Wave Signal Generator Module 
Printed schematic, installation and operation instructions