Led dimming circuit (pwm)

Sorry, I found some projects with PWM, I tried most of them, and without any luck

Can someone who tried that post me a schematic?

Or if someone would be so nice paint a layout on prototype board? please...

can be variable frequency, or constant (houndreds of Hz)

Duty cycle range 1% - 99% or something like that...

Best would be to use 555 Timer

want to make it for high power LED(s) some Watts.

Thanks for an advice

 

well,

a PWM schematic using the 555 can be found on www.ti.com datasheet.
With the 555 you can not really achieve the PWM range you have asked for...

by the way if nothing you have tried work, it could be also due to some mistakes you have done.

Probably if you post the schema you have used, people can better see where the problem is...

Ciao,

Mauro

 

hi,

I have tried this:

http://www.reuk.co.uk/LED-Dimmer-Circuit.htm

but if you or somebody else has a schema with some other IC and could be used for my purpose I would be very greatful

In short,

I want to dim a high power LED or some high power LEDs with a trimer lineary without any flicker effect. Dont know what frequeny must it be to dont notice being the LED turned on/off.

 

try without any result...

is there someone who did the PWM and want to send me a photo or paint of prototype board...

please

 

it is working

http://www.elecfree.com/electronic/...simple-pwm-circuit-based-on-the-555-timer.gif

i figured out the 555 chip was wrong.. i replaced it with another and it is modulating

 

Yes I did thanks a lot Bill...

I have another question... Can be this schema, or Bill's modified, or added by something to do this:

there should be a button to do the following:

1. Press : Turn on by fading in the LED to the intensity setted up by potenciometer...
2. Press : Delayed by few seconds, and than fading out till switching off

thanks for advices

 

Which schema should be best? Could you send me a direct link for the purpose I describe you Bill please?

 

Sorry Bill, but I dont understand you... For what is not a good time? And I dont get the schematic eighter... Square wave out = my output for the LED. Right?

For what is the PWM out?and the R1... Should it not have three pins?

sorry, but I really dont get it