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Upgrading your foldable magnifier with a multi-level brightness LED-light

Picture of Upgrading your foldable magnifier with a multi-level brightness LED-light
A magnifier is a very handy tool when working with electronics. But often, when the light in the room isn't bright enough, it is still hard to see the tiny codes written on top of IC's and SMD parts. So I decided to add a light to my foldable magnifier.

I had some hyperflux LEDs lying around that allowed me to get high and low brightness out of one led with still plenty of light in both modes. A switch was added to choose the level of brightness.

Step 1: What do you need?

Picture of What do you need?
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  • A foldable magnifier (mine only cost € 2.50)
  • A hyperflux LED with 3 'LEDs' in it.
  • 3 x 150Ohm resistor
  • A powerconnector
  • A single pole, double throw tumbler switch
  • A bit of protoboard
 
Why not use a potentiometer?
janw (author)  The Ideanator3 years ago
I had not really space for a potentiometer if the magnifier still had to be foldable.

And I prefer PWM dimming instead of dimming with a potentiometer.
Space? Looks like theres loads of space in there, wheres your hacksaw? ;)

A PWM setup would require more space than a pot any day, how would you modify the pulse width? if you want powersaving, look up those joule theives.
janw (author)  The Ideanator2 years ago
A PWM setup can be done in a lot less space than a potentiometer. As I only need an attiny and a pushbutton for it (2 buttons would be ideal but it can be done with one). But I didn't want to spend an attiny on this project if I can get a good result with only the switch.

I don't prefer PWM because it saves power but because, as Ynze stated in his comment, PWM is a smoother, more accurate and more controllable way of dimming LEDS.
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pfred2 janw2 years ago
The only advantage PWM has over resistance is in power savings, other than that resistance is smoother, more accurate, and more controllable. Resistance is often cheaper and always simpler hardware too. But sometimes the power savings outweighs all the other benefits of resistance so that is why it is used.
Try to avoid dimming leds with a potmeter. It works, but PWM is much more accurate (smoother dimming).
pfred23 years ago
I have a magnifier exactly like this. I got mine for $1 at a yard sale. Sometimes lighting is an issue with it.
janw (author)  pfred23 years ago
That's indeed why I made this little 'upgrade' .
Did this about 10 years ago but used 4 leds, one in each corner & a 9V battery for convienence (no cord). It met an unfortunate end & got crushed. Worked like a charm though !! Cheers!
janw (author)  Lectric Wizard3 years ago
I also use a 9V battery but I also can use a cord if I like. I was able to do it with only 1 as the led is very bright.