2x NE555 Adjustable Module Duty Cycle Pulse Frequency Square Wave Signal
 
Product Information
 
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 for microcontroller (MCU) applications.
 
Only 31mm x 22mm (1.2" x 0.9"), the board 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  5 - 6V DC and draws approximately
15mA at 5v with an output amplitude of 4.2V peak-to-peak to 5.2V 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:
Size: 31mm * 22mm
Main chip: NE555
Input Voltage (VCC): 5V-6VDC (6V MAX) (Overvoltage will destroy Chip, not covered)
Input current:~100MA Max
Output amplitude: 4.2V V-PP to 5.2V V-PP. (Varies with VCC voltage)
Maximum output current: 15MA (VCC=5V, 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

The output frequency and duty cycle are adjusted using the following variables:

Period T = 0.7 (RA +2 RB) C
RA, RB are 0-10K Ohm adjustable potentiometers
1Hz ~ 50Hz: C = 0.001UF
50Hz ~ 1kHz: C = 0.1UF
1KHz ~ 10kHz: C = 1UF
10kHz ~ 200kHz: C = 100UF
 

Applications:
As a square wave signal generator for experimental development
Used to drive a stepper motor for generating a square wave drive signal
Generate adjustable pulses for microcontrollers (MCU)
 
2x NE555 Signal Generator PCB Supplied