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General project discussion / help
Did you make a robotic coffee pot which implements HTCPCP and decafs unauthorized users? Show it off here!
By heisenburg4412
#176953
Hey all, I'm a new user and I'm looking for some help/guidance on my project. I have a small 3v motor that I'd like to add speed control to. The only problem is that I have a very limited space issue. I don't have space to add any sort of breadboard to my project. I was wondering if this is at all possible, thanks in advance!
By Mee_n_Mac
#176954
How much current (max) does this small motor draw ? How were you intending to input your desired speed ? Are you dialing up a speed via a manual control or is there a control voltage or ??? that's going to set the speed ?

If the motor is "small" enough you might get away with putting a pot (as a rheostat) in between the voltage and the motor. Not the most efficient way but as simple as possible.
By heisenburg4412
#176984
waltr wrote:Search for PWM motor control.
This can be done with a 555 and a transistor.
Unfortunately I don't think this will work for me. My space is very limited and from what I see I don't think it'll fit in the space I need it to, unless there is some sort of tiny version of it. I have a space about 17 mm by 33 mm.
By heisenburg4412
#177016
Sorry I'm really new to this but the knob is gonna be on the outside of the container so no worries about that. What about if I wanted to do it like a toothbrush with clicking it comes a different speed like a 3 speed deal. How would I achieve that?
By Mee_n_Mac
#177034
The simplest way would use a multiple position switch and put a different resistor in series w/the motor. The resistor reduces the current to the motor and thus it's speed. This is however not the most efficient way. It's the same as my 1'st suggestion, but with fixed resistances vs a variable one (the pot).
Image

OTOH if you want to use a single push button switch to "click through" the speeds, then the micro-controller approach (an ATtiny or PIC plus a FET) would be better.