Pulsating direct current

Thread Starter


Joined Oct 5, 2010
Hello guys,

I have seen Pulsating direct current I guess a months ago but never have any interest of it, my fault.:D

It says that it is like a direct current however varies in intensity at a regular interval time.:D

What does this mean, please? So it's like that for example the regular interval time is one second, then for every one second interval the current stops and back again and so?

Where can I get that kind of current? Batteries also?

Please help..


Joined Dec 20, 2007
DC electric motors, incandescent light bulbs and electric heaters are efficiently controlled with Pulse-Width-Modulation which are pulses of DC current. The width of the pulses controls the speed of the motor and the amount of light and heat.

Look at pulse width modulation in Google.


Joined Jul 17, 2007
You can use batteries as the DC supply, and then something like a 555 timer IC driving a transistor or MOSFET to get different ratios of ON to OFF time.

Bill_Marsden has some 555 timers used as PWM sources in his blog.