Hi Mike,

 

That should work.  SnapAmp can drive 2 DC Brush Motors at 12.5A cont. each.

 

Regards

TK

Group: DynoMotion	Message: 5569	From: michaelthomasn	Date: 8/17/2012
Subject: Re: Snap Amp Question

Tom, So I got to wondering today.....if a DC servo motor makes X amount of torque at a particular working rpm, will lowering the voltage also reduce the torque at the same rpm? I understand the rpm goes down, and therefore the power, but what happens to torque? Mike --- In DynoMotion@yahoogroups.com, Michael Niksch <michaelniksch@...> wrote: > > Ok.....thanks. Every time I look at the snapamp spec chart I seem to overlook the fact that what is stated is only one half of the amp. > > Mike > > On Aug 17, 2012, at 9:42 AM, Tom Kerekes <tk@...> wrote: > > > Hi Mike, > > > > That should work. SnapAmp can drive 2 DC Brush Motors at 12.5A cont. each. > > > > Regards > > TK > > > > From: michaelthomasn <michaelniksch@...> > > To: DynoMotion@yahoogroups.com > > Sent: Thursday, August 16, 2012 7:47 PM > > Subject: [DynoMotion] Snap Amp Question > > > > > > Hi Tom, > > > > Everything has been going great with the grinder.....Just wanted to say thanks again on that. > > > > I'm wondering if a SnapAmp can be set to use its full power to drive one DC Servo. > > > > I bought a Mazak Quick Turn 20n, and it has a pretty hefty Z servo motor. > > > > The manual says its 1.1Kw at 116v. I realize that I can only use 80 with the SnapAmp....but I dont think a little less voltage will be too big of a deal since I'm not concerned with top speed. > > > > Mike > > > > > > > > >

Group: DynoMotion	Message: 5570	From: Tom Kerekes	Date: 8/17/2012
Subject: Re: Snap Amp Question

Hi Mike,   No.  Torque is very much proportional to current.  It usually only takes a small voltage to overcome the motor resistance to make the current flow and generate torque.  If you know the motor resistance you can calculate this.  For example to get 10 Amps of current to flow through 0.5 ohms only takes 5V.  The majority of the voltage is used to overcome the bemf of the motor.  So for example at 1000RPM the motor acts like a generator and might be generating 50V.  If 50V is applied to the motor no current will flow and there will be no torque.  55V would be required to make 10Amps flow and generate the same torque that 5V would at a standstill condition.   HTH TK Group: DynoMotion Message: 5571 From: Michael Niksch Date: 8/18/2012 Subject: Re: Snap Amp Question Thanks Tom , That was a helpful explanation. Mike On Aug 17, 2012, at 10:22 PM, Tom Kerekes <tk@...> wrote:   Hi Mike,   No.  Torque is very much proportional to current.  It usually only takes a small voltage to overcome the motor resistance to make the current flow and generate torque.  If you know the motor resistance you can calculate this.  For example to get 10 Amps of current to flow through 0.5 ohms only takes 5V.  The majority of the voltage is used to overcome the bemf of the motor.  So for example at 1000RPM the motor acts like a generator and might be generating 50V.  If 50V is applied to the motor no current will flow and there will be no torque.  55V would be required to make 10Amps flow and generate the same torque that 5V would at a standstill condition.   HTH TK