how to build a simple resistor for low output

[lightknight]

Hi guys,

as the title says, i've been wondering if there is some material which could be simply put between the battery an head of a light to reduce its brightness and by that improve its runtime.

Is there any "natural semi resistor" like this - maybe just a kind of foil or fabric, something you might find in every household?

Greez, Eric

 

[Helmut.G]

This method would only work in a light that is not regulated as a regulation circuit would simply draw more power from your batteries hence giving you the same brightness with less runtime.

I think that there are only very few materials that you could use and that it would be hard for you to achieve the right resistance.

It would be easy to build some kind of spacer using an "ordinary" resistor with the disadvantage that the heat from the resistor wouldn't be spread evenly over the device depending on the material you use.

 

[rockz4532]

pencil lead works

 

[VidPro]

yes even pencil Graphite would work.
you can split a pencil, and put clip leads on it and have a dimmer even
draw a line on a piece of paper, and connect to both ends of the line (of course paper could burn)

a Light bulb, some small dashboard or festoon or small dome light bulb will work as a resister. even the right AC light bulb will work.

small wire in long lengths, especially non copper type wire, the average wire like telephone wire will often drop quite a bit.

Water , with various substances in it, like salt.

a battery can not only add voltage, but reversed it will subtract it, that of course is a very bad idea, not safe to do that.

just more leds in series till you reach an approproiate voltage/current.

potatoes, lemons, various water filled fruits and veggies

 

[lightknight]

This method would only work in a light that is not regulated as a regulation circuit would simply draw more power from your batteries hence giving you the same brightness with less runtime.



Well, my regulated lights get dimmer, when the battery turns empty.
So it seems that regulation has its limits too.