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View Full Version : Just a few ideas to have looked over for possiblities



Warlock
02-04-2009, 09:08 AM
How does the 555 timer "light dimmer" work?

http://www.electronics-tutorials.com/devices/555-light-dimmer.htm

Dimming Control for a white led driver

http://www.edn.com/article/CA472839.html

Dc Lamp Dimmer

http://www.edn.com/archives/1997/102397/22di_04.htm

And finally Difitally Controlled Dimming using a different angle..

http://www.circuithut.com/index.php?/circuit/content/view/full/363

As always thanks guys...
Joe..

phenagan
02-04-2009, 02:22 PM
Looked at for what possibilities?

Three of them use pulsewidth modulation to do the dimming, which is how we dim now, and the one related to LEDs shows both PWM controlled dimmers and current controlled dimmer, which is only applicable to LEDs. Although current controled dimming is an alternative to PWM for LEDs, the problem with it is that it doesn't make for a "generic" dimmer as you have to match the the circuit output to current requirements for the particular LEDs attached, i.e., you'd have to match the circuit to drive whites or reds or blues, etc to have good control of them. Current controlled dimming also tends to add more components to the mix than PWM.

Please don't take this the wrong way, but I do have to ask you a question.. How much electronics experience do you have? I ask because you've posted about wanting to design your own controller, but then you post this asking how a 555 based dimmer works. This is a pretty basic circuit, one that I encountered very, very early in my electronics classes.

Warlock
02-04-2009, 03:34 PM
Been out of electronics for 10 years now..Seriously getting back in now...So much as changed since I was last into it that I seen the circuit designs and simply asked about the logic or possiblity of building something around these ideas.Mainly asking for opinions with regards to the idea of the principle of the design not the design itself..It (for example) was the only basic fet dimmer circuit I could find...So it was posted as an idea to use..Simple as that...Even the pwm circuits use 2 different approaches of doing the same thing in the end...Just more or less askin which is the best or most logical approach to using either fets or simple pwm and triacs...