+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 20 of 29

Thread: DC motor speed control

  1. #1
    Join Date
    Oct 2007
    Location
    Lancashire.
    Posts
    4,134
    Blog Entries
    1
    Rep Power
    324042

    Default DC motor speed control

    A couple of pics of the speed control I've built for Dougie. It'll drive a new larger Maxon motor which I'll be fitting to his Linn soon enough.

    Red led is 33 1/3 rpm. Dougie's new motor is currently installed in my Linn.


    Green led is 45 rpm.


    And a quick shot of the rear of the unit. The case will match your phono stage Doug having the same frontal dimensions but much longer at 220mm.


    There's a 50VA toroid in that box. The psu is split rail and well regulated. The trimmers are on the front as it's a bloody pain to adjust them when access is at the back. I hope you like it Dougie
    Si.

  2. #2
    Join Date
    Jun 2007
    Location
    Birmingham
    Posts
    11,243
    Rep Power
    1792670

    Default

    Smashing work Si, I love the feature of turning a knob until an LED lights to set the speed. Any other PSUs do that?

  3. #3
    Join Date
    Oct 2007
    Location
    Lancashire.
    Posts
    4,134
    Blog Entries
    1
    Rep Power
    324042

    Default

    I think there's one or two that do that Gary, OL maybe one of them. The rotary switch is a four pole three way unit so I used a spare pole to switch the leds. The leds are wired back to back but the opposite way round to each other. Because one led is conducting and the other isn't, simply reversing the polarity lights the other led and visa versa. I had a friend(s) over on PFM design the thing for me and it ended up a group buy but I had problems getting it to work with different motors and at different speeds. I gave up with it for a while and I think it's died a death anyway now but I've reworked a few bits and pieces and it appears to work well now. It is specific to the motor though and not universal. I have five of these up and running now and a new pcb layout is on the cards for next year.
    Si.

  4. #4
    Join Date
    Nov 2007
    Location
    glasgow, ,
    Posts
    1,585
    Rep Power
    338996

    Default

    Quote Originally Posted by TIU View Post
    Smashing work Si, I love the feature of turning a knob until an LED lights to set the speed. Any other PSUs do that?
    Gary, the Pink Triangle GTI supply does that too and extremely attractive too being behind a frosted knob.

    Si, very nice work, can that be adapted work with a Garrard 401 ?.

  5. #5
    Join Date
    Jun 2007
    Location
    Birmingham
    Posts
    11,243
    Rep Power
    1792670

    Default

    Quote Originally Posted by Chops54 View Post
    I think there's one or two that do that Gary, OL maybe one of them. The rotary switch is a four pole three way unit so I used a spare pole to switch the leds. The leds are wired back to back but the opposite way round to each other. Because one led is conducting and the other isn't, simply reversing the polarity lights the other led and visa versa. I had a friend(s) over on PFM design the thing for me and it ended up a group buy but I had problems getting it to work with different motors and at different speeds. I gave up with it for a while and I think it's died a death anyway now but I've reworked a few bits and pieces and it appears to work well now. It is specific to the motor though and not universal. I have five of these up and running now and a new pcb layout is on the cards for next year.
    That's easy for you to say but may as well be in Swahili to me. I doff my cap to you Si.

  6. #6
    Join Date
    Feb 2008
    Location
    Carmarthenshire, West Wales.
    Posts
    1,031
    Rep Power
    155406

    Default

    Quote Originally Posted by Chops54 View Post
    I think there's one or two that do that Gary, OL maybe one of them. The rotary switch is a four pole three way unit so I used a spare pole to switch the leds. The leds are wired back to back but the opposite way round to each other. Because one led is conducting and the other isn't, simply reversing the polarity lights the other led and visa versa. I had a friend(s) over on PFM design the thing for me and it ended up a group buy but I had problems getting it to work with different motors and at different speeds. I gave up with it for a while and I think it's died a death anyway now but I've reworked a few bits and pieces and it appears to work well now. It is specific to the motor though and not universal. I have five of these up and running now and a new pcb layout is on the cards for next year.
    Si.
    Looks excellent! I'm sure Douglie will be thrilled.

    I'm still waiting patiently for your definitive list of components to suit a Maxon DC motor. I still have a couple of pcb's in waiting.


    Regards

    John R.

  7. #7
    Join Date
    May 2007
    Location
    scotland, , United Kingdom
    Posts
    5,829
    Blog Entries
    1
    Rep Power
    351399

    Default

    yea well done Si...looks excellent!!
    www.audioorigami.co.uk

    And visit my face book page--- check out Audio Origami

    http://www.facebook.com/AudioOrigamiTonearms

  8. #8
    Join Date
    Oct 2007
    Location
    Lancashire.
    Posts
    4,134
    Blog Entries
    1
    Rep Power
    324042

    Default

    Thanks for those words of encouragement lads. It's taken me a while to get this thing working something like and the answer was really quite simple. I'm still hoping to improve on it for next year. I've no intention of competing with anyone else and it isn't a kit. It's specifically for my own turntables though I'll be quite happy to retro fit it to a customers turntable in the near future.

    John, apologies again. I was stalling because I came across a problem that I couldn't fix. On my own deck which has the belt around the circumference of the platter there was no issue but as soon as I put the kit on my Linn it didn't work as it should. I very nearly gave up on it and binned the lot. You saw how long the thread went on for on PFM and I'm sure quite a few gave up on it. I need to know exactly which motor you have so I can get the psu to work correctly. I may even need the motor so I can run it. I actually have a box here on my desk with all the components for your board and yes I know it's been here a long time. I also know that some parts will need changing. When I get back from Dougie's we'll sort it out.

    As for those leds, initially I wasn't going to use any but I decided that if I was going to put a led on the front to indicate power on then I might as well use two and indicate the speed and kill two birds. The switch is off in the centre which stops the motor but the front half of the psu stays powered. This keeps the regs warm so speed drift is not an issue in the first few minutes of use. The leds are off of course when the switch is in the centre position.

    Crackpot, it's a dc motor speed control so it's no good for you mate I'm afraid.
    Si.

  9. #9
    Join Date
    Oct 2009
    Location
    Shit Creek Sans Paddle.
    Posts
    4,172
    Rep Power
    1642871

    Default

    Cracking piece of work there Si. Beautiful in its (visual) simplicity if that makes sense. Useing the leds to indicate rpm was a neat touch i reckon Si.
    Elitist scum vinyl owner

  10. #10
    Join Date
    Feb 2008
    Location
    Carmarthenshire, West Wales.
    Posts
    1,031
    Rep Power
    155406

    Default

    Quote Originally Posted by Chops54 View Post
    T

    John, apologies again. I was stalling because I came across a problem that I couldn't fix. On my own deck which has the belt around the circumference of the platter there was no issue but as soon as I put the kit on my Linn it didn't work as it should. I very nearly gave up on it and binned the lot. You saw how long the thread went on for on PFM and I'm sure quite a few gave up on it. I need to know exactly which motor you have so I can get the psu to work correctly. I may even need the motor so I can run it. I actually have a box here on my desk with all the components for your board and yes I know it's been here a long time. I also know that some parts will need changing. When I get back from Dougie's we'll sort it out.

    No worries Si - I'm not in a rush, I just took the opportunity to remind you that's all ! Great work tho!

    Are my PC boards likely to be U/S now that you've incorporated mods? Motor choice is likely to be the DC 100 unless you suggest otherwise?

    Regards.

    John R.

  11. #11
    Join Date
    Oct 2007
    Location
    Lancashire.
    Posts
    4,134
    Blog Entries
    1
    Rep Power
    324042

    Default

    Your boards are ok John but I have to alter them slightly. The switching is a bit more complicated. In the original layout the resistor networks that control the speed are always in parallel irrespective of which network is selected and one therefore effects the other. I split them so that only one network is in circuit at any one time. This gives the extended voltage range needed for 45 rpm which was not always attainable before. There are some other changes which are more to do with convenience than anything else and are down to personal choice. I'll email you with those and the Maxon motor variants.

    Thanks for that Keith. Simplicity is the key I think. I do like my creations to look fit for purpose but adornment is not one of my talents and I'm glad you approve. If any money is to be spent I like it to go where it counts.

    Having said all that the knob could be better and will be replaced with a turned aluminium one in due course.
    Last edited by Chops54; 22nd August 2011 at 21:33.
    Si.

  12. #12
    Join Date
    Nov 2007
    Location
    glasgow, ,
    Posts
    1,585
    Rep Power
    338996

    Default

    Thanks for letting me know Si, shame it's not suitable for 401 as it's a seriously good looking piece of kit and no doubt it's a real good performer, keep up the good work.

    As a matter of interest, is the phonostage you built for Dougie housed in the same case?.

    wii.

  13. #13
    Join Date
    Oct 2007
    Location
    Lancashire.
    Posts
    4,134
    Blog Entries
    1
    Rep Power
    324042

    Default

    Well thank you kindly sir Yes and no to the enclosure. Same frontal aspect but about twice the length. I'm considering using the longer case for the phono stage as well in the future as it is rather tight in the smaller case especially with those boutique caps I've been using. Having said that I've decided that fancy components are not reqd in my builds any more, not that I did much of that anyway. I'll stick to good quality proven parts and no bull.
    Si.

  14. #14
    Join Date
    Feb 2008
    Location
    Carmarthenshire, West Wales.
    Posts
    1,031
    Rep Power
    155406

    Default

    Quote Originally Posted by Chops54 View Post
    Your boards are ok John but I have to alter them slightly. The switching is a bit more complicated. In the original layout the resistor networks that control the speed are always in parallel irrespective of which network is selected and one therefore effects the other. I split them so that only one network is in circuit at any one time. This gives the extended voltage range needed for 45 rpm which was not always attainable before. There are some other changes which are more to do with convenience than anything else and are down to personal choice. I'll email you with those and the Maxon motor variants.
    That'll be great Si thank you very much !

    John R

    Quote Originally Posted by Chops54 View Post
    Having said all that the knob could be better and will be replaced in due course.
    At great risk of lowering the tone, I guess we all quietly hanker after a better knob !

    Regards.

    John R

  15. #15
    Join Date
    Oct 2007
    Location
    Lancashire.
    Posts
    4,134
    Blog Entries
    1
    Rep Power
    324042

    Default

    Haha yes indeed John. As long as it's big enough to fill a pram, who gives a toss anyway
    Si.

  16. #16
    Join Date
    Feb 2009
    Location
    Glenrothes
    Posts
    853
    Rep Power
    211433

    Default

    Wii my friend. Long time no see, I hope things are picking up. All the best mate.
    Coincidences - Gods way of reminding you that he's here.

  17. #17
    Join Date
    Feb 2009
    Location
    Glenrothes
    Posts
    853
    Rep Power
    211433

    Default

    Looking good Si, it's got to have a bit more poke than the OL, which in my opinion underperforms. With a little luck it should transform me Lp12.

    See you Friday.
    Coincidences - Gods way of reminding you that he's here.

  18. #18
    Join Date
    Oct 2007
    Location
    Lancashire.
    Posts
    4,134
    Blog Entries
    1
    Rep Power
    324042

    Default

    I'm confident you'll be happy with it Dougie. I now have three turntables up and running, one of them being my much modified Linn Sondek, the one in the black Henk plinth. Hugh's heard this Linn several times with the both motors and I think he was suitably impressed with the upgrade to the bigger motor. He's been over tonight to pick up the rest of his Linn bits and take a butchers at your motor speed control and he also had a quick listen to the Od'A Empire turntable.

    Yes I'll see you Friday Dougie.
    Si.

  19. #19
    Join Date
    May 2007
    Location
    Glasgow
    Posts
    7,925
    Rep Power
    209997

    Default

    Quote Originally Posted by Dougie View Post
    Wii my friend. Long time no see, I hope things are picking up. All the best mate.
    Yeah how you doing Andy? Hope all is well.
    Do to others as you would have them do to you. (Luke 6:31)

    From that time on Jesus began to preach, “Repent, for the kingdom of heaven has come near.” (Matthew 4:17)

  20. #20
    Join Date
    Nov 2007
    Location
    glasgow, ,
    Posts
    1,585
    Rep Power
    338996

    Default

    Quote Originally Posted by Dougie View Post
    Wii my friend. Long time no see, I hope things are picking up. All the best mate.
    Thanks Dougie and ditto Umberto, i am fine now and slowly surfacing from the Abyss, cheers for now.

+ Reply to Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts