Pulse Width Modulation with NE555

Hi makers!

One of the most fundamental problems in robotics is controlling the speed of a DC motor. The most common speed control method is PWM (Pulse Width Modulation). Pulse Width Modulation is the process of varying the power delivered to a device by switching it on and off at a specific frequency. These on/off switching intervals are referred to as the "Duty Cycle." The diagram below shows waveforms for 10%, 50%, and 90% duty cycles.

https://electrodb.ro/control-turatie-motor-prin-varierea-factorului-de-umplere-pwm/

Thus, the duty cycle describes the pulse width as a percentage. A 10% duty cycle means the device receives current for 10% of the cycle, while it receives none for the remaining 90% of the time. A 100% duty cycle means the device receives current continuously, rendering PWM unnecessary.

These signals are sent to the motor at a sufficiently high frequency so that the pulsing itself does not adversely affect the motor's operation. The end result of the PWM process is that the total power delivered to the motor can be adjusted from 0% to 100% duty cycle, ensuring high efficiency and stable control.

In the PWM circuit, the 555 timer is configured as an astable oscillator. This means that once power is applied, the 555 will oscillate without requiring any external trigger.

Circuits of this type allow for motor speed control ranging from 0% to 100% while maintaining constant torque. In principle, the NE555 circuit generates a signal at a specific frequency that is applied to a monostable stage, the timing period of which is determined by the value of a resistor. While N-channel transistors can be used, circuit variants employing P-channel transistors also exist; the difference in the latter case is that the load is placed between the source and the power ground, while the drain is connected to the power rail (the positive voltage supply).

I just designed the PCB for my own use, I am not the original author so check the link source.
Source:

https://electrodb.ro/control-turatie-motor-prin-varierea-factorului-de-umplere-pwm/

This project is presented "as is" and is intended for personal use. Most of the time I use salvaged components or buy from local store.

I think you can easily tell who I had this PCB made by (*manual assmebled). 🤓😁

#PCB# #NE555#