24v 300w power supply

  • Thread starter E. Lee Dickinson
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E. Lee Dickinson

Guest
Hello, All -

I am curently working on a project (automated scenery, to explain the
crosspost) for which I need a 300 watt motor. I'm looking at a 300w 24v DC
motor, since I am pretty comfortable with DC motor speed and direction
control.

My problem is in coming up with the power source for that. I prefer to buy
a readymade power supply, but everything I'm seeing is either $1000 or "not
for variable loads." I'm not adverse to building a supply, but I know
little beyond the fact that I need a transformer, rectifier, and regulator.

Any suggestions? If the best answer is, "Learn how to control AC motors,"
I'm open to that, but I've been told that AC motors don't reverse well and
don't operate well at low speeds. This project has to change speed and
direction fairly rapidly.

Thanks in advance.

:Lee
 
either use an industrial servo drive, or get a 300w 24V transfomer and a
rectifier. The transfer will probably run you about 30 or 40 bucks, teh
rectifier will probably cost you less than 5 bucks.

..02 from
Chris Warner

"E. Lee Dickinson" <lee@ihatespam_leedickinson.com_ireallyhateit> wrote in
message news:c9gove$mnr$1@solaris.cc.vt.edu...
Hello, All -

I am curently working on a project (automated scenery, to explain the
crosspost) for which I need a 300 watt motor. I'm looking at a 300w 24v
DC
motor, since I am pretty comfortable with DC motor speed and direction
control.

My problem is in coming up with the power source for that. I prefer to
buy
a readymade power supply, but everything I'm seeing is either $1000 or
"not
for variable loads." I'm not adverse to building a supply, but I know
little beyond the fact that I need a transformer, rectifier, and
regulator.

Any suggestions? If the best answer is, "Learn how to control AC motors,"
I'm open to that, but I've been told that AC motors don't reverse well and
don't operate well at low speeds. This project has to change speed and
direction fairly rapidly.

Thanks in advance.

:Lee
Click to expand...

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How automated is this scenery? If you need a lot of torque, maybe you
could research an alternative using hydraulics?

I work at UPS stateside, and there are several miles of belts. Some of
them can go in reverse from the flick of a switch. All run off AC and
have some transmission things that turn the rpms into an unbelievable
amount of torque. None of them change speed though. I know some high
pressure fountain (the water kind) displays like the one at the Dorothy
Chandler Pavillion in Los Angeles use some kind of electronic 'thing' to
drop the frequency from 60 hz to something variable between 10-30 hz,
keeping the voltage the same.

Torrance
 
On Mon, 31 May 2004 22:16:51 -0400, "E. Lee Dickinson"
<lee@ihatespam_leedickinson.com_ireallyhateit> wrote:

Hello, All -

I am curently working on a project (automated scenery, to explain the
crosspost) for which I need a 300 watt motor. I'm looking at a 300w 24v DC
motor, since I am pretty comfortable with DC motor speed and direction
control.

My problem is in coming up with the power source for that. I prefer to buy
a readymade power supply, but everything I'm seeing is either $1000 or "not
for variable loads." I'm not adverse to building a supply, but I know
little beyond the fact that I need a transformer, rectifier, and regulator.
Click to expand...
There's a bloke in Adelaide (that's South Australia to you furriners) selling
some brand new Lucent units that would appear to more than meet your needs. He
seems to have a steady availability so might be worth contacting him.

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&category=296&item=5702486892
 
On Mon, 31 May 2004 22:16:51 -0400, "E. Lee Dickinson"
<lee@ihatespam_leedickinson.com_ireallyhateit> wrote:

Hello, All -

I am curently working on a project (automated scenery, to explain the
crosspost) for which I need a 300 watt motor. I'm looking at a 300w 24v DC
motor, since I am pretty comfortable with DC motor speed and direction
control.

My problem is in coming up with the power source for that. I prefer to buy
a readymade power supply, but everything I'm seeing is either $1000 or "not
for variable loads." I'm not adverse to building a supply, but I know
little beyond the fact that I need a transformer, rectifier, and regulator.

Any suggestions? If the best answer is, "Learn how to control AC motors,"
I'm open to that, but I've been told that AC motors don't reverse well and
don't operate well at low speeds. This project has to change speed and
direction fairly rapidly.

Thanks in advance.

:Lee
Click to expand...
Hello Lee,
I am a cheapskate, so I would be scrounging a couple of
car batteries that can no longer start a car engine but
still have some life left in them. You can get them for free.

Battery chargers. You can find them everywhere. Bludge one
from your mates/aquaintances. Float charge your batteries.
On the night when the batteries are used often, stick the
charger on boost.

Here is a forward reverse stop motor controller already made up.
http://www.tecel.com/d200/
http://www.tecel.com/d100/
Price looks to be very fair.

Speed control circuit, here is one that you could adapt to the
the above motor controller since it has to be PWM under I KHz.
http://www.solorb.com/elect/solarcirc/pwm1/
That one operates at 400 Hz.
You don't need the power Fet.
Reduce the PWM output signal to 5 volt maximum
to suit the d200 input.

You don't have to use the tecel H bridge.
Just reverse the motor using a heavy duty switch, or
better still, a heavy duty relay. (automotive from wreckers).
Use the speed controller as it is shown.

Some food for thought. Sounds like an intersting project.
Have fun.

Regards,
John Crighton
Sydney
 
These Vicor power supplies will work just fine with
variable loads. But expect to pay about a dollar a watt.

http://www.vicr.com/products/dc-dc/power_supplies/vipac/

We use these in our DARPA Grand Challenge vehicle.

But really, you're better off finding an industrial
motor controller that runs from 110VAC or 220VAC.

Incidentally, it's worth noting that "brushless DC"
motors and "AC synchronous motors" are the same thing.
Large servomotors (above 1HP) are usually referred to
as "AC synchronous", while small motors are referred to
as "brushless DC". So if you're having trouble finding
larger servomotors and controllers, that may be the problem.

Synchronous AC servomotors are available all the way up
to locomotive size.

The phrase to search for is "industrial drives".

John Nagle
Team Overbot

E. Lee Dickinson wrote:
Hello, All -

I am curently working on a project (automated scenery, to explain the
crosspost) for which I need a 300 watt motor. I'm looking at a 300w 24v DC
motor, since I am pretty comfortable with DC motor speed and direction
control.

My problem is in coming up with the power source for that. I prefer to buy
a readymade power supply, but everything I'm seeing is either $1000 or "not
for variable loads." I'm not adverse to building a supply, but I know
little beyond the fact that I need a transformer, rectifier, and regulator.

Any suggestions? If the best answer is, "Learn how to control AC motors,"
I'm open to that, but I've been told that AC motors don't reverse well and
don't operate well at low speeds. This project has to change speed and
direction fairly rapidly.

Thanks in advance.

:Lee
Click to expand...
 
On Mon, 31 May 2004 22:16:51 -0400, E. Lee Dickinson
<lee@ihatespam_leedickinson.com_ireallyhateit> wrote:

Hello, All -

I am curently working on a project (automated scenery, to explain the
crosspost) for which I need a 300 watt motor. I'm looking at a 300w 24v
DC
motor, since I am pretty comfortable with DC motor speed and direction
control.

My problem is in coming up with the power source for that. I prefer to
buy
a readymade power supply, but everything I'm seeing is either $1000 or
"not
for variable loads." I'm not adverse to building a supply, but I know
little beyond the fact that I need a transformer, rectifier, and
regulator.

Any suggestions? If the best answer is, "Learn how to control AC motors,"
I'm open to that, but I've been told that AC motors don't reverse well
and
don't operate well at low speeds. This project has to change speed and
direction fairly rapidly.

Thanks in advance.

:Lee
Click to expand...
The phrase "as well" is more like it, AC motor controllers have improved
dramatically in the last 15 years. & just build a slightly oversized PSU &
you shouldn't need a regulator for most DC controllers.
 
My 60V 13A power supply can be reconfigured for 30Vat 27A
see
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=26209&item=3818127323&rd=1&ssPageName=WDVW

Dan
"E. Lee Dickinson" <lee@ihatespam_leedickinson.com_ireallyhateit> wrote in
message news:c9gove$mnr$1@solaris.cc.vt.edu...
Hello, All -

I am curently working on a project (automated scenery, to explain the
crosspost) for which I need a 300 watt motor. I'm looking at a 300w 24v
DC
motor, since I am pretty comfortable with DC motor speed and direction
control.

My problem is in coming up with the power source for that. I prefer to
buy
a readymade power supply, but everything I'm seeing is either $1000 or
"not
for variable loads." I'm not adverse to building a supply, but I know
little beyond the fact that I need a transformer, rectifier, and
regulator.

Any suggestions? If the best answer is, "Learn how to control AC motors,"
I'm open to that, but I've been told that AC motors don't reverse well and
don't operate well at low speeds. This project has to change speed and
direction fairly rapidly.

Thanks in advance.

:Lee
Click to expand...
 
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