Comments on Eastern Geek: Simple (and dirty) Pulse Width Modulation (PWM) Fo...

I want to run a .3 Amp 90mmx90mm case fan with thi...

2012-01-28T05:53:35.473+08:00

I want to run a .3 Amp 90mmx90mm case fan with this. What changes do I have to make so it can pass the current? My input voltage is 12-18 Volts. I am running the fan with 8 AA batteries. Would a more complicated circuit draw less current so my batteries would last longer. I like this simplicity and would like to use it on a product that I developed. http://uralica.com/biomass-stove.htm

can i use a TORQUE - TUNED MOTOR (e.g. TAMIYA moto...

2011-12-22T20:41:52.788+08:00

can i use a TORQUE - TUNED MOTOR (e.g. TAMIYA motor..) ? thank you !

i DID IT AND IT WORKED!!! This is my first electr...

2011-11-17T08:02:44.353+08:00

i DID IT AND IT WORKED!!!

This is my first electronic project like this in 38 years.
I built an amplifier and a synth when I was 12.

I am so happy and proud of myself.
It actually worked and it works perfectly. Really really nice.
Thank you so much for posting the circuit and making the video, and showing the love. Gracias!!

@lokomotiv It needs a PNP transistor (TIP30 or TI...

2011-09-12T13:32:21.641+08:00

@lokomotiv

It needs a PNP transistor (TIP30 or TIP32 series works well). NPN doesn't work

Connect the PNP transistor base pin to pin 7 through a resistor to limit the base current/voltage.

Pim: How did you connect the PNP transistor? I am ...

2011-09-12T04:19:42.466+08:00

Pim: How did you connect the PNP transistor? I am trying to control a bigger motor with PWM signal using NPN Transistor, it dose not work. Did you connect pin 7 to base?

I have tried this with pnp transistor and rgb led ...

2011-04-09T04:20:51.873+08:00

I have tried this with pnp transistor and rgb led strip, I have noticed it never reaches 0%, the leds are never fully off, even adding resistors. Is it possible with your circuit ?
Another question, when running a motor, if I use PNP to PWM ground, it can control very low speeds, when PWM positive, not so low. I am beginner, and this is a nice experiment.
Thank you for sharing.

Hey Couple of questions. My 555 does not have a no...

2011-03-15T03:26:32.312+08:00

Hey
Couple of questions.
My 555 does not have a notch or markings on it. How do I know what side is what? Also does the diode number matter that much? I can not seem to find 1N4148 anywhere.
Thanks
David

Hi Chein, thx for the schematic! I got it working...

2011-03-02T04:53:12.780+08:00

Hi Chein, thx for the schematic!

I got it working with a LED and a small motor but I want to implement a transistor to control a motor that needs more amps.

Where in the schematic do I connect it?

Thanks again!

More likely the 555 ic is fried. As noted in the p...

2010-11-28T13:14:21.706+08:00

More likely the 555 ic is fried. As noted in the post, the circuit can pass max 200mA. In your case, think you should replace the ic and add a limiting resistor to your circuit.

As for the value of the resistor, Google for "current limiting resistor", there are many guides on how to calculate the right value.

Hi Chien, I built the circuit following your inst...

2010-11-26T23:38:44.553+08:00

Hi Chien,

I built the circuit following your instructions and thought I'd built it properly but now (two days before the presentation for my project) I have found out that I am only able to control my motor speed in a very narrow range. Could I have damaged the pot? The video you posted shows I should be able to control the speed all the way down to zero. What am I doing wrong?

hi ' i try to build it but it bont work can u ...

2010-09-01T02:30:44.575+08:00

hi ' i try to build it but it bont work can u help me... i use a simple motor like that of playstation controll pad shock .. and also a led... completly out of of work... help me

That's so simple PWM circuit.. working nicely...

2010-07-31T23:06:54.837+08:00

That's so simple PWM circuit..

working nicely..

BTW,, can u make one for RF ie wireless speed control(PWM)..

thnx

Ok, not sure how old this post is (i really didn&#...

2010-06-17T02:47:54.474+08:00

Ok, not sure how old this post is (i really didn't look) but was hoping to get one question answered. I have been looking for a cheap reliable PWM design, you have supplied that (and THANK YOU!) but could you rig two circuits, one on each side of the pot two control two separate motors at inversed speeds?

HI CHEIN NICE JOB MAKING PWM SIMPLE. CAN I ASK Y...

2010-04-14T21:23:25.499+08:00

HI CHEIN

NICE JOB MAKING PWM SIMPLE.
CAN I ASK YOU HOW MANY AMPS CAN IT TAKE? AND CAN IT BE USED FOR HHO'S?

Alisdair Yes you can use a DPDT switch to reverse...

2010-03-04T23:05:50.144+08:00

Alisdair

Yes you can use a DPDT switch to reverse the spin.

Hi Chein Thanks for sharing this with us! Can yo...

2010-03-04T06:48:29.175+08:00

Hi Chein

Thanks for sharing this with us!

Can you advise whether this can be used with a DPDT switch between motor and circuit for a reversible motor?

If this is not possible can you please suggest a way to introduce a reversible switch?

Apologies for my ignorance on this!

Thanks in advance
A

Hi, I am wanting to use three of these (I have alr...

2010-02-16T21:14:09.519+08:00

Hi,
I am wanting to use three of these (I have already made and tested them) to control multiple RGB LEDs.
The LEDs have a common negative and therefore these will not work as the currently stand.
How can I change the output to +ve?
Would you suggest using a transistor to do this and link it with the source +ve?

Cheers

Hello guys.I have tried the circuit with a pot whi...

2010-01-06T22:34:04.363+08:00

Hello guys.I have tried the circuit with a pot which I think is 10k.It didn't work.Could this be the reason.Everything else is the right component.I used a motor from a toy which I think is a standard one.Thanks.

MLF - I think your 555 is fried. For your purpose,...

2010-01-04T09:27:32.375+08:00

MLF - I think your 555 is fried. For your purpose, should add a current limiting resistor or a FET at the output pin instead.

Hello Chein, I built your circuit to run a small ...

2009-12-30T12:08:59.655+08:00

Hello Chein,
I built your circuit to run a small DC motor to work as an electric telescope focuser. It should work fine once I am finished but I hit a snag.

When run by a 6v (four AA batteries) it worked fine, but the motor didn't seem to have much tourque in slow mode so I connected it to a 12v computer power supply I use as a 12v source.

Trouble is it didn't

Love it! Nice and simple. So, how would one add ...

2009-12-19T05:34:10.981+08:00

Love it! Nice and simple. So, how would one add a level indicator to this? Such as 5 led level or something similar? Thanks!

Hi Chein, I made this circut with all the parts yo...

2009-12-01T16:56:23.905+08:00

Hi Chein, I made this circut with all the parts you metioned. I used a 9v battery and a 1.5v-3v dc motor. It didnt work :(

I'm just wondering what voltage your motor was.

Thanks.

Hello, Can you please suggest the modification fo...

2009-11-29T04:07:30.516+08:00

Hello,

Can you please suggest the modification for controlling the brightness for a 40/60 Watt bulb, working on 230v AC,
or a CFL bulbs brightness?

can i use the same ckt? or will there be any modifications.
and how do i connect the bulb or CFL?

Please help.

Thanks in advance

The photos are very clear and the breadboard appro...

2009-11-21T15:03:31.751+08:00

The photos are very clear and the breadboard approach is nice. I want to add a reed switch/magnetic sensor or something simple to provide input to the trigger/pin. I tried a Hall sensor but smoked it. Any ideas?

Hi Chein, I was wondering how powerful was the mot...

2009-11-16T02:50:22.262+08:00

Hi Chein, I was wondering how powerful was the motor you were using? I have a 6-12 volt dc motor. Will it work with this circut?

Thanks.