Jump to content




Photo

Professor Motor controller ohm rating


  • Please log in to reply
9 replies to this topic

#1 ThunderThumb

ThunderThumb

    On The Lead Lap

  • Full Member
  • PipPipPipPip
  • 258 posts
  • Joined: 05-March 19
  • Gender:Male
  • Location:Orange County

Posted 15 May 2020 - 12:00 PM

How do you tell how many OHMs does a Professor motor controller has , this has the sensitivity and brake controls and us the more expensive controller they sell , its a few years old , thanks
Earl Anderson




#2 Eddie Fleming

Eddie Fleming

    Checkered Flag in Hand

  • Subscriber
  • PipPipPipPipPipPip
  • 1,580 posts
  • Joined: 27-April 14
  • Gender:Male
  • Location:Fayetteville, GA

Posted 15 May 2020 - 01:10 PM

The sensitivity control kind of takes the Ohm rating out of the question. The question is does it have enough sensitivity range to cover what you want to do with it?

 

So what do you want to run with it?


Eddie Fleming

#3 ThunderThumb

ThunderThumb

    On The Lead Lap

  • Full Member
  • PipPipPipPip
  • 258 posts
  • Joined: 05-March 19
  • Gender:Male
  • Location:Orange County

Posted 15 May 2020 - 01:20 PM

HO scale cars , thanks
Earl Anderson

#4 Eddie Fleming

Eddie Fleming

    Checkered Flag in Hand

  • Subscriber
  • PipPipPipPipPipPip
  • 1,580 posts
  • Joined: 27-April 14
  • Gender:Male
  • Location:Fayetteville, GA

Posted 15 May 2020 - 01:34 PM

I can't help you with much if anything HO. Someone will have an answer for you. 


Eddie Fleming

#5 mreibman

mreibman

    On The Lead Lap

  • Full Member
  • PipPipPipPip
  • 202 posts
  • Joined: 19-March 18
  • Gender:Male
  • Location:Merrick, NY

Posted 15 May 2020 - 03:04 PM

Write to professor motor, support@professormotor.com

I feel like this was the answer yesterday to someone else.

 

they will answer whatever they can, they were really good with me when I acquired one of their controllers.


Mike Reibman
Alleged amateur racer
Mostly just play with lots of cars.
Able to maintain slot cars with a single bound.
Faster than a speeding womp.
More powerful than a 36D
 
 


#6 ThunderThumb

ThunderThumb

    On The Lead Lap

  • Full Member
  • PipPipPipPip
  • 258 posts
  • Joined: 05-March 19
  • Gender:Male
  • Location:Orange County

Posted 15 May 2020 - 03:10 PM

Thanks for the info
Earl Anderson

#7 Ramcatlarry

Ramcatlarry

    Posting Leader

  • Subscriber
  • PipPipPipPipPipPipPip
  • 2,643 posts
  • Joined: 08-March 06
  • Gender:Male
  • Location:St Charles, IL 60174

Posted 15 May 2020 - 09:03 PM

Until recently, the PM controllers have been diode or transistor controllers and available as either Positive or Negative gate. Both design concepts can be set up as HO, 1/32 homeset, or commercial level controllers.  Buying a used one can be a problem if you need the right combination - I know - I have a few HO models I bought that I would like to sell or trade.  Our 1/32 Club use that model with Positive gate as 'house controllers' so that no one has to bring a fancy controller to race night.

 

Best way of telling is to hook it up and see if it works. The wrong gate will not run at all.  I have tried to strip the board of all electronic bits and rebuild and do not want to put that much time into redoing the transistor models.  Older diode models are not so bad to make over.

 

If it is a newer resistor model, just meter the wiper board to ID it.  Polarity does not matter on resistor controllers unless a diode is in the circuit somewhere to isolate it.


Larry D. Kelley, MA
retired raceway owner... (for now)
race directing around Chicago-land

 

Diode/Omni repair specialist
USRA 2017 member #404
USSCA  member

Host 2006 ISRA/USA Nats
Great Lakes Slot Car Club member
60+ year pin Racing rail/slot cars in America


#8 bradblohm

bradblohm

    On The Lead Lap

  • Full Member
  • PipPipPipPip
  • 345 posts
  • Joined: 22-November 06
  • Gender:Male
  • Location:Westland, MI, USA

Posted 16 May 2020 - 09:11 AM

Oliver has been alone in the PM shop for weeks due to the lockdown in Michigan.  He is getting to things as best as he can but some things get delayed, and email and phone support has for sure been less of a priority.

 

As for the controller, as has been said you can't think of it in terms of ohm rating.  First question, again, has been pointed out, is if it's a positive or negative polarity setup.  The old diode controllers could be altered to add a switch to flip, but the newer transistor models actually use a different transistor, so no easy switching.  There's nothing obvious on the controller to tell you that, so...  Assuming it is a match for how your track is wired the next question is operating voltage range.  The low voltage controllers have internal resistor packs which allow the controller to operate between around 9-13 volts, and the high voltage controllers have resistor packs to operate between around 12-18 volts.  You won't hurt anything, but if you use a low voltage controller at say 16 volts you will lose sensitivity and it will start feeling like an on-off switch.  A high voltage controller used at say 10 volts will feel very sluggish until full throttle.  The sensitivity knob will help some, but...

 

Hope this helps.


  • Ramcatlarry likes this

Brad Blohm


#9 SpeedyNH

SpeedyNH

    Old Engineer

  • Subscriber
  • PipPipPipPip
  • 340 posts
  • Joined: 18-July 15
  • Gender:Male
  • Location:Cow Hampshire

Posted 16 May 2020 - 03:33 PM

the problem with using prof motor ctlrs. with HO cars is that they're sensitive to the track Voltage due to their circuitry.  unless some parts are changed inside, using them on the usual (around here anyway) 18V results in too high a threshold on the sensitivity control.  sometimes gravity cars run on 10V, and then one can have the opposite problem. they like 12-13V, unless specifically built for a different scale/use. 


Steve Lang

#10 bbr

bbr

    Checkered Flag in Hand

  • Full Member
  • PipPipPipPipPipPip
  • 1,705 posts
  • Joined: 08-March 12
  • Gender:Male
  • Location:LA

Posted 16 May 2020 - 05:38 PM

On most "transistor" controllers the sensitivity range has to be adjusted to the type of racing.
The only controller that I have used that didn't have this issue is Carsteen. I have used it for all kinds of scales and forms of racing and the on board sensitivity adjustment knob is good enough
Mike Low
Cry like a baby, drive like a girl, walk like a man.
Give me enough rope and I'll build a fast car... or hang myself?





Electric Dreams Online Shop