12V Brightness Control Module.

[Nickk2057]

Hey guys. am trying to make an LED 12V brightness control dimmer for my LED's but am not sure of what i can use out of old electronics. (which i have a ton of them around the house and two sheds) any idea?

[the_memristor]

Hey Nickk2057, you can use the good old NE555 for generating PWM to control the brightness. A nice circuit can be found here: http://www.reuk.co.uk/LED-Dimmer-Circuit.htm
I build it up myself several times and it always works like a charm.

[Nickk2057]

Hey Nickk2057, you can use the good old NE555 for generating PWM to control the brightness. A nice circuit can be found here: http://www.reuk.co.uk/LED-Dimmer-Circuit.htm
I build it up myself several times and it always works like a charm.

well the LED's is 12V but 17W what would i use to handle the power?

[jlmoon]

Drive the 555 with a Power Mosfet.. look up IRF series
 
should do the trick

[the_memristor]

Hey Nickk2057, you can use the good old NE555 for generating PWM to control the brightness. A nice circuit can be found here: http://www.reuk.co.uk/LED-Dimmer-Circuit.htm
I build it up myself several times and it always works like a charm.

well the LED's is 12V but 17W what would i use to handle the power?

Just replace the motor with your leds (D3 is not needed by using LEDs)

[Nickk2057]

Hey Nickk2057, you can use the good old NE555 for generating PWM to control the brightness. A nice circuit can be found here: http://www.reuk.co.uk/LED-Dimmer-Circuit.htm
I build it up myself several times and it always works like a charm.

well the LED's is 12V but 17W what would i use to handle the power?

Just replace the motor with your leds (D3 is not needed by using LEDs)

from what i see on that link and on that image is that the LED's will not power all the way down (turn off) on the 555 circuit. but then i seen that i COULD use the Arduino board with a 5V regulator in the circuit to power the Arduino and a MOSFET to the light. i will post a pic in a sec of the lights i am using.

EDIT: here is the image of the lights i am using. NOW MIND YOU that i have modded them to be only used as 12V. the one on the right is 17W and the left is 15W

[Nickk2057]

also what i am wanting to use these for is to help my friend in his photography by making some lights to help in saving him some money.

this is one of the photo's that i helped in the lighting at a shoot with them with a prototype of the lights i did that is a simple on-off.

[the_memristor]

Wow! As I scrolled down the topic on my smartphone your picture was shown full-screen and I nearly got an heart attack    
Very good photo by the way
You're right, the range dutyrange of the 555 circuit will between 5% to 95%. I used a potentiometer with a build in rotaryswitch to switch the lamp completly off. Like this one:


You can certanly use a Arduino for PWM generation Simple connect a potentiometer (voltage divider configuration) to a ADC pin of the Arduino and set the PWM out according to the ADC value.
But take care when selecting the MOSFETs, for example the IRFZ 14 seems to be big enough with I_DS_Max = 10A. BUT if you look to the "typical output characteristics", you will see this FET can only drive at VGS = 5V (output voltage of an arduino pin) at a VDS = 0.3V (RDS_on = 0.2 Ohms * 1.5A (I_DS)) a maximum current of 1A. -> Would be a bad choice

Better: IRFZ44ZPbF with an I_DS_Max = 51A seems much to big, but has much better specs than the IRFZ 14.

It's only an advice to be on the safe side