Does anyone here know anything about switching power supplies, of the 
sort sold nowadays to power laptops and some LCD monitors?

I'm using one to power an 18V motor used in a reed profiling machine, 
and it's giving me certain problems.
It supplies 19V at 7.7A, and seems to be adequate for the task.

The reed profiler:
http://groups.yahoo.com/group/MouthpieceWork/photos/recent/219646748/view

The power supply turns the profiler motor nicely for extended periods 
without a problem,  but the motor will start ONLY if I power up by 
switching on AC into the supply (basically plug it in) with the motor 
already connected

I put a switch on the motor for convenience, but with the power supply 
already energized, flipping the motor on/off switch does nothing, or 
advances the motor a few degrees.

I'm guessing that the sudden large current draw of the switched on motor 
"looks" like a short circuit to the power supply's safety circuitry, and 
it powers down automatically.

For whatever reason, switching the whole thing via AC works - although 
there is about 1 sec delay before the motor starts.

Is there some kind of fix I can apply?

Barry Levine

--- In MouthpieceWork@yahoogroups.com, Barry Levine <barrylevine@...> wrote:
>
> Does anyone here know anything about switching power supplies, of the 
> sort sold nowadays to power laptops and some LCD monitors?
> 
> I'm using one to power an 18V motor used in a reed profiling machine, 
> and it's giving me certain problems.
> It supplies 19V at 7.7A, and seems to be adequate for the task.
> 
> The reed profiler:
> http://groups.yahoo.com/group/MouthpieceWork/photos/recent/219646748/view
> 
> The power supply turns the profiler motor nicely for extended periods 
> without a problem,  but the motor will start ONLY if I power up by 
> switching on AC into the supply (basically plug it in) with the motor 
> already connected
> 
> I put a switch on the motor for convenience, but with the power supply 
> already energized, flipping the motor on/off switch does nothing, or 
> advances the motor a few degrees.
> 
> I'm guessing that the sudden large current draw of the switched on motor 
> "looks" like a short circuit to the power supply's safety circuitry, and 
> it powers down automatically.
> 
> For whatever reason, switching the whole thing via AC works - although 
> there is about 1 sec delay before the motor starts.
> 
> Is there some kind of fix I can apply?
> 
> Barry Levine
>
 Assuming that the switching supply is driving a DC motor, I would try an electrolytic capacitor of say 100 Microfarad or more, voltage 25 Volt or more, across the motor terminals, observing the polarity of the capacitor.
  Eddie McLean

 

Thanks. Yes, DC motor. Already tried 1250 & 2200 uF, which only
jogged the motor a bit when it was switched on. 

I posted this earlier,
but hasn't appeared yet, don't know if it will, so I thought to answer
you directly and thank for the tip. 

At least the motor will run if
started up by plugging in the supply. It's just not as nice a setup.


Barry 

>> 
> Assuming that the switching supply is driving a DC
motor, I would try an electrolytic capacitor of say 100 Microfarad or
more, voltage 25 Volt or more, across the motor terminals, observing the
polarity of the capacitor.
> Eddie McLean
> 
> __.

 

Then put the switch on the AC line.





________________________________
 From: barrylevine <barrylevine@...>
To: mouthpiecework@yahoogroups.com 
Sent: Wednesday, August 14, 2013 4:52 PM
Subject: Re: [MouthpieceWork] Re: OT: Power supply to motor on DIY Reed Profiling machine
 


  
Thanks.  Yes, DC motor. Already tried 1250 & 2200 uF, which only jogged the motor a bit when it was switched on.
I posted this earlier, but hasn't appeared yet, don't know if it will, so I thought to answer you directly and thank for the tip.
At least the motor will run if started up by plugging in the supply. It's just not as nice a setup.
Barry
>
>Assuming that the switching supply is driving a DC motor, I would try an electrolytic capacitor of say 100 Microfarad or more, voltage 25 Volt or more, across the motor terminals, observing the polarity of the capacitor.
>Eddie McLean
>
>
>__.
 
 

I use meanwell power supplies in both, my CNC lathe/mill, and my spindle drivers.
I have killed a few, because of swarf getting into the cases.  They are relatively cheap, and I always have an extra on the shelf.




________________________________
 From: barrylevine <barrylevine@norwoodlight.com>
To: mouthpiecework@yahoogroups.com 
Sent: Wednesday, August 14, 2013 5:52 PM
Subject: Re: [MouthpieceWork] Re: OT: Power supply to motor on DIY Reed Profiling machine
 


  
Thanks.  Yes, DC motor. Already tried 1250 & 2200 uF, which only jogged the motor a bit when it was switched on.
I posted this earlier, but hasn't appeared yet, don't know if it will, so I thought to answer you directly and thank for the tip.
At least the motor will run if started up by plugging in the supply. It's just not as nice a setup.
Barry
>
>Assuming that the switching supply is driving a DC motor, I would try an electrolytic capacitor of say 100 Microfarad or more, voltage 25 Volt or more, across the motor terminals, observing the polarity of the capacitor.
>Eddie McLean
>
>
>__.