NE555 Adjustable Pulse Frequency Duty Cycle Module Square Wave Signal Generator

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.

Specifications :

Main chip: NE555
Input Voltage (VCC): 5V-15VDC
Input current:~100MA
Output amplitude: 4.2V V-PP to 11.4V V-PP. (Varies 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. When the frequency is higher than about 30Hz, the LED will appear to be always on since the blinking is too fast to see.
There is a 4-row x 2-pin header that provides jumper settings to select different frequency ranges. The jumper connects different value capacitors in the circuit to change the RC time constant of the circuit. The multi-turn potentiometer near the frequency range jumper provides fine control over the frequency once the range is set.
Jumper settings are:
~1Hz ~ 40Hz
~40Hz ~ 500Hz
~500Hz ~ 40kHz
40kHz ~ >200kHz
The jumper ranges will vary between modules depending on the tolerances of the components used.
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