Simple DC motor control - Page 30

Wilky · #**436** 14-03-10, 06:14 AM

Thought I'd pop this thread back up.

I'm going to get on and start building this project now the case has arrived.
Has anyone else got any further with their projects?

Dave.

sq225917 · #**437** 14-03-10, 07:06 AM

Built several of them and made several variations on each one along the way as well. Change your Rs for a 25 turn trimmer of suitable range, it makes cancelling the commutation filter and feedback loops much easier.

Which motor are you using, looks nice?

Wilky · #**438** 14-03-10, 07:20 AM

Hi Sq.

Thanks for the advice on the resistors, I'll get it all sat on the bench and test as much as I can before finally casing it all up.

The motor is this one, but bought from Trident Engineering, not RS.
http://uk.rs-online.com/web/search/s...duct&R=2532515

The details are in post#411.

A better looking spec than the Maxon motors, but obviously I'll be needing to tweek the circuit to get the motor running in it's 'sweet spot'.
But for now I will be using a standard OL tall pulley as it fits this motor's 3mm shaft perfectly.

I can always get a new pulley machined up to get where the desired results, but I wanted to get up and running.

Dave.

starbuck · #**439** 14-03-10, 09:14 AM

What case and transformer are you using, if you don't mind me asking?

Wilky · #**440** 14-03-10, 10:59 AM

Hi Starbuck.

The transformer is a 2 x 12v 15VA from Farnell

http://uk.farnell.com/multicomp/mcfe...61?Ntt=9531661

The case is from OKW enclosures (www.okw.co.uk) and is Teko part no DS1470.18 (called Dissipator)

http://www.teko.co.uk/enclosures/19.htm

Will post a few pix later...

Dave.

starbuck · #**441** 14-03-10, 04:15 PM

Thanks for the info, Dave - a nice case was something I was looking for and I think the one you've got there could be just the thing for me.

sq225917 · #**442** 15-03-10, 05:07 AM

wilky, just out of interest do you know your pulley/latter ratio?

sq225917 · #**443** 18-03-10, 08:11 AM

Here's a funny one.

I cased mine up last night, same parts as were lying on the floor. The difference is the speed used to flutter. With it in the box it's perfect...

Work that one out.

Lokes · #**444** 26-03-10, 02:41 PM

Hi, I would like to buy a circuit board if anyone has a spare ?
Jules

Pulse Studio · #**445** 26-03-10, 02:48 PM

Quote:

Originally Posted by Lokes

Hi, I would like to buy a circuit board if anyone has a spare ?
Jules

HI Jules

You have PM, I have 2 spare PCB's and that's all.

Paul

hifijev · #**446** 05-06-10, 03:48 AM

Hi all, any PCB's left? I need a controller, a motor and a pulley for my Scheu Premier with a motor that has stopped working...

clivem2 · #**447** 06-06-10, 11:58 AM

I've got a couple of spare pcbs. PM me.

Werner · #**448** 08-07-10, 12:48 AM

Just to show what you are up against when attempting load compensation: these are scope shots of an unloaded 24V Premotec CL40 motor fed 6V. The motor current is passed through a 10 Ohms resistor at the bottom end. The top of this resistor is connected to the scope, so every 10mV equals 1mA. The average current is 8mA.

dobbykins · #**449** 12-07-10, 08:40 PM

Does anyone happen to have a spare PCB I could buy off of them? Thanks in advance!

croak · #**450** 20-07-10, 12:54 PM

Just an update. I built/am building a controller (it needs building in a box and the LED switching done) and the first op amp I had to hand was an opa134. She zoomed in to speed quite easily and looks stable on strobe.
Thought the 134 may be overkill and had some ripped out JRc 5534s. Plopped it in to the socket and lo and behold, much harder and more sensitive to trim to speed and it almost seems though there is the odd shudder. So, the OP134 went back in and the greater sense of stability . Just thought I would share what could be worthwhile tweaks.