My first post here..

[WalkingWithWalnuts]

Welcome to the forums i guess? Thanks in advance

Looks like a stunning place to hang out if i want some knowledge about smal stuff which i am in to.

Only got one question right now. What is the smallest (dimensionally) potentiometer i can buy? It needs to have a mechanical lever or a screw knob but the main thing is i want it to be very small. It is for manipulating very small r/c hobby motors from 0 to 6 AA/AAA battery volts mainly. I`ve picked up some on ebay but these are a little too big for my liking and oh so generic. Are there any truly small ones on the market?

Thanks, Bjørn in Norway

 

[Harald Kapp]

Welcome to EP.
I don't know whether tese are the "smallest" ones, but very likely they are.
Example 1
Example 2
Naturally they come without an axle - afaik none of these small ones do as adding an axle adds size. You can add an axle by inserting a plastic stick (suitably prepared to fit the center of the pot) or simply glueing one to the center.

It is for manipulating very small r/c hobby motors from 0 to 6 AA/AAA battery volts mainly.

A typical potentiometer is not meant to control power as the power to a motor. Potentiometers are menat to be operated at virtually no power (o.k., very, very small power) to create control signals which in turn control a power driver (e.g. a motor driver) for the high powre load. Using a potentiometer directly to control motors is likely to burn the potentiometer quickly.

 

[WalkingWithWalnuts]

Well i`m not 100% familiar with all the terms yet, maybe it`s not called a potentiometer after all? These are what i already have.

Low Voltage DC 3V 5V 6V 9V 12V 2A PWM DC Motor Pump Speed Controller Regulator | eBay

Find many great new & used options and get the best deals for Low Voltage DC 3V 5V 6V 9V 12V 2A PWM DC Motor Pump Speed Controller Regulator at the best online prices at eBay! Free shipping for many products!

www.ebay.com

DC 12V/24V Brushless DC Motor Speed Regulator DC 8-30V BLDC PWM Speed Controller | eBay

Find many great new & used options and get the best deals for DC 12V/24V Brushless DC Motor Speed Regulator DC 8-30V BLDC PWM Speed Controller at the best online prices at eBay! Free shipping for many products!

www.ebay.com

They are too big for my needs. Maybe the ones in your link are a little too low on capacity since they are so small?

From time to time i pluck apart electronic appliances and save the itty bitty odds and ends. I found this little thing inside a dvd player once. The stick is spring loaded but i have no idea if it is a voltage regulator as such or something else. Can i buy stuff like this "loose" anywhere?

 

[dragon]

why do you need them so small - have u got a crazy idea?

One reason I can think of is if u wanted to make a really tiny robot with little dc motors and u hook em up to em for the angle sensors, but maybe little tiny hall sensors work better.

hall sensors are really small and u just hover a magnet near them and they are as good as potentiometre, they can be used for same thing.
Small voltage instead of small resistance, is just a design workaround.

 

[WalkingWithWalnuts]

why do you need them so small - have u got a crazy idea?

One reason I can think of is if u wanted to make a really tiny robot with little dc motors and u hook em up to em for the angle sensors, but maybe little tiny hall sensors work better.

hall sensors are really small and u just hover a magnet near them and they are as good as potentiometre, they can be used for same thing.
Small voltage instead of small resistance, is just a design workaround.

One reason i need them small is i work a lot with small scale static models. If i am going to integrate such a device, it would be inside a wooden piece maybe no thicker than 1cm...a display piece with batteries and a power regulator for motors & lights etc. Seems to me this is the easiest way to go about it. I want it to be wired (opposite of wireless) so i would not be able to use regular micro r/c equipment which ofcourse relies on some form of wireless communication. Never heard of hall sensors before, reading about it online now. Well it looks like a clever way to control the power of electrons, but i don`t know what type of conductor to buy if i was to build something from scratch so it would be easier for me to buy some type of switch instead. I have a lot of loose ends to cope with still, so something easy is preferrable.

 

[dragon]

Linear hall sensors just give you an amplitude depending on how far the magnet is away,so it works like one those thevenin's (musical instrument where you hover your hand in the air next to it to change control parametra.), if you could mount the magnet on a little slider next the sensor it would be the same as a potentiometre.