Pwm Circuit Using 555. The circuit is very simple i have used 555 ic and some basic electronics components to make this speed control of dc motor using pwm. This problem can be avoided by using pulse width modulation.
The basic idea is to vary the input signal which is supplied to the control pin of the ic. The circuit is very simple i have used 555 ic and some basic electronics components to make this speed control of dc motor using pwm. The circuit uses a potentiometer to vary the output pwm signal from around 5 to 95 of the power supplied and uses a jumper to vary the frequency from around 1hz to 10khz.
Hence if we replace r2 with a potentiometer we can control the charging and discharging tines of the capacitor and essentially the duty cycle of the pwm signal.
The collector current of the transistor or drain current of the mosfet should be greater than the dc motor max current rating. The circuit uses a potentiometer to vary the output pwm signal from around 5 to 95 of the power supplied and uses a jumper to vary the frequency from around 1hz to 10khz. This circuit is operated at 12 volts dc. From the above circuit diagram of 555 timer in astable mode it is clear that the capacitor is charging through r1 and r2 while it is discharging only through r2.
