LED Dimmer

#3
I think the diagram given for this circuit is incorrect. I built it months ago with no luck, and was always concerned that the 50K potentiometer between the two identical diodes facing the same way made no sense. I eventually gave up on it. I saw the same diagram on another website, but noticed that one of the 4148's faced the opposite way unlike the diagram given on this site. Is this why my dimmer never worked? I will build it again tomorrow and see if it works with this change.
 
#5
Hi there.

I need a modified version of this circuit.
I plan to use a electrical timer to turn LEDs on or off. So, when timer is on, it will slowly fade LEDs in and keep them on. And when timer is off, it will slowly fade them out.
And I need longer fade in/out times.
Could someone please help me?

Thanks.
 
#6
Any suggestions on how to troubleshoot this circuit? I'm supplying it with 5.2V and the LED just flashes on when I apply power then turns off. It's not fried. It does the same thing if I disconnect and reapply power. The flash is dim or bright according to the setting of the potentiometer though, so the dimming portion is working, the LED is just not staying on.
 
#7
Any suggestions on how to troubleshoot this circuit? I'm supplying it with 5.2V and the LED just flashes on when I apply power then turns off. It's not fried. It does the same thing if I disconnect and reapply power. The flash is dim or bright according to the setting of the potentiometer though, so the dimming portion is working, the LED is just not staying on.
my bench supply is 6vdc and i test circuits with it first to keep from frying things. when i built this ,and like so many others the correct voltage , i had to supply 9vdc. i built a voltage stepper to set it in at 9vdc and it worked. i also build voltage doublers to achieve a 12vdc yet they have low amperage supply.
 
#8
my bench supply is 6vdc and i test circuits with it first to keep from frying things. when i built this ,and like so many others the correct voltage , i had to supply 9vdc. i built a voltage stepper to set it in at 9vdc and it worked. i also build voltage doublers to achieve a 12vdc yet they have low amperage supply.
Thanks. I'll try it with a 9v supply. I did try it with a 12 vdc supply without success. Still learning! :)
 
#9
to kbarnette and all hello , it's easy to overlook a wire or component not touching or the solder broke loose moving a component around as this was my errors of past and sometimes now i catch myself going crazy . last night i was building a led tri colored night light and started playing with different capacitors to get different effects. by mistake i lost my place and had left 2 0f the 3 caps out during a swap and connected 3vdc to it. it works! just check and play with different combinations as i do at times and then it is fun.