home sweet home...

yeah yeah... I'm going down under :-D

my spare time software projects...

my spare time hardware projects...

courses and projects completed (by me) on the Technical University of Denmark...

my old class from Amtsgymnasiet Sønderborg

my image gallery... if you're (un)lucky, you might find yourself in there...

tag a comment om my wall...

time to move on?

drop me a line...

Light dimmer

August 2009
Quick update: Got some more time on my hands now and some more knowledge in my brain :) So a rebooted the project and have now designed a light dimmer circuit, which I hopefully will try out in the near future... If it works, I will try to get a PCB fabricated - and in the end probably post a short description here with diagrams and everything :) If you're interested, drop by this page again some time in the end of 2009 - you might get lucky :)

This project has been going on for some while. Or rather, it has been set aside for a while... When I first started it, I saw it as a quick little project that would take a month or so from it was begun till it would be completed. But things turned out differently...

I have a little drinks cabinet (should I post a picture?) with 2 halogen light spots in it. The cabinet is built with the lights to be allways on at full power but I thought it could look cool with the light dimmed. Or rather: Ordinarily Normal it should be dimmed. When opening the cabinet, the lights should be slowly turned up to maximum. When closing the cabinet the light should be slowly dimmed back. Here the word slowly is about 1 or 2 seconds.

I know that dimming halogen lights is not quite good for them, but well... As I wrote: I just thought it could look cool :-)

I started out with building a pulse width modulation circuit using a 555 timer IC but did not get got results. The duty cycle of the pulse width was a bit unstable and (even worse) my effect transistor did not seem to open up for the current to the lights. Theese errors are obviously my own faults although I did not get around to correct them - or even make sure what was really going on. As I wrote, I had expected the project to be a quick one and when it did not work, I sort of lost interest and had other pressing things to do.

Later on I got the idea to just modify (yes: fiddle or tamper with it, as someone might say) the original power supply to fit my needs. I dont use it anyway (no lights on in my cabinet). The power supply is an electronic model (switch mode) and if I could control the voltage level on the output, I could easily (?) put an R-C circuit (delay circuit) on it to make it slowly go from dimmed state to maximum power. Only troubles is: I do not have much experience with switch mode power supplys. Nor do I have a circuit layout of the power supply (I have tried to make one, although I am not sure it is entirely correct). And last but not least: I lack the time...