Help! i need a DC motor speed controller

Discussion in 'The Projects Forum' started by ChrisChemist116, Mar 13, 2009.

  1. ChrisChemist116

    Thread Starter Active Member

    Mar 13, 2009
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    Hi:), i am trying to build a very simple motor speed controller, for a small toy-type DC 3V motor.

    I have been looking this simple project on many sites, but because my electronics skills are very limited i would like to know if there is any schematic (breadboard friendly) which can be useful for me that can skip the hard task to use microcontrollers i.e. PIC, EEPROM or whatever and hard to find chips or outdated ones (as TDA7274 http://www.datasheetcatalog.org/datasheet/stmicroelectronics/1481.pdf) (did i mention i am a pic programming disabled?).

    The only requirement i have for this project is, i am forced to use a 9V pp3 battery as power source.

    The rest is just to control the motor speed by adjusting some sort of trimmer, but of course i am aware other components would be needed.

    Well, i hope someone could help me with this matter, i need to do this as a science project for my university class.
    Thanks in advance.

    ---
    I am sorry if my english skills maybe not good because is not my mother language.
     
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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  3. ChrisChemist116

    Thread Starter Active Member

    Mar 13, 2009
    78
    1
    Thanks for the quick answer. I haven't found that link when i did my first search.
    I am quite happy with the design because i can understand it, but after a close read I am quite worried that 9Volts can over heat or burn the 3V motor as the design seems to be made for a pc fan.
    The page doesnt say if would control the spin from zero movement to full power.
    Does the schematic would need any adjustment on parts list for running well with a 3 V motor?
    Before i go to electronics store, i need to be sure this thing will work.
     
  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    The 555 output is about 2V lower than the supply voltage.

    Change supply to 5V and it should all be good for a 3V motor.

    See This Thread for details, or if you need a transistor to boost available current.
     
  5. ChrisChemist116

    Thread Starter Active Member

    Mar 13, 2009
    78
    1
    Thanks, i will try as you mentioned. Once i finish the project maybe i can post a picture of how it looks like.

    By the way, is a trimpot/trimmer same as linpot (linear potentiometer)? (sorry if it sounds like a silly question) does both generate the same effects?
     
  6. ChrisChemist116

    Thread Starter Active Member

    Mar 13, 2009
    78
    1
    Well:), after several testing rounds, i found this design very usefull and seems to work fine for me , if anyone is interested on this matter may check at this site http://www.siliconchip.com.au/cms/A_104678/article.html under the section motor speed controllers.

    I experienced some problems to getting this project to work (per see http://www.cpemma.co.uk/pwm.html#nomad refered earlier ), the potentiometer seemed to not decrease or increase the spinning in the motor (did i mentioned i am using brushed DC motor?).

    Perhaps this project works perfectly in a pc fan as such device is not exactly a brushed dc motor, maybe i am wrong, anyways thanks for the guy who gave me the first hint. I am sorry to be new on this.
     
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