Looking for a schematic/suggestions

[Don Bruder]

The goal:
A power supply that outputs a solidly regulated +5.0VDC at 500+mA under
load, fed from a ridiculously variable input supply - basically anything
that can feed it enough juice to give the required output - Batteries,
solar cells, a mini-windmill, a DC motor spun-to-operate-as-a-generator
- whatever.

As currently envisioned, I'm thinking of feeding it using a scavenged
stepper motor that used to operate the tractor-feed of an old line
printer - The unit I have in mind is labeled as wanting 40VDC at 10
amps, and after some creative wiring for testing, I've found that
spinning it with fingers gets it to put out an extremely "wobbly" (and
noisy as hell when looked at with an o-scope) 6-25 volts, with no idea
what the amperage is - suspect it's probably pushing "a couple amps",
give or take. (Yeah, I know... working to such close tolerances is a
real pain in the arse )

I figure to mount it on a little push-cart I use frequently,
friction-coupled to one of the wheels, MAYBE through a gear-train to
bump up the RPMs. Ultimate goal: Charge/operate an iPod/iPhone/similar
usually-USB-powered toy without ever needing to plug the unit into a
"real" USB port.

Suggestions? Comments on feasibility? Diagnoses of my particular mental
aberration(s) and/or ideas for suitable medications to cure it/them?

--
Security provided by Mssrs Smith and/or Wesson. Brought to you by the letter Q

 

[Ralph Mowery]

"Don Bruder" <dakidd@sonic.net> wrote in message
news:mdb921$ept$1@dont-email.me...

The goal:
A power supply that outputs a solidly regulated +5.0VDC at 500+mA under
load, fed from a ridiculously variable input supply - basically anything
that can feed it enough juice to give the required output - Batteries,
solar cells, a mini-windmill, a DC motor spun-to-operate-as-a-generator
- whatever.

You can use a three terminal voltage regulator and a couple of capacitors.
Just search for a 7805 voltage regulator. It will take a voltage source
from about 7 volts to 35 volts and give you 5 volts out at up to around 1
amp.

You can go to ebay and order an adjustiable regulator board that does the
same thing for about $ 2. Good thing about this one is that as you go
higher in input voltage, the ammount of current you can draw is more than
the input current.

ebay number 151251686795

 

[Baron]

Don Bruder prodded the keyboard with:

The goal:
A power supply that outputs a solidly regulated +5.0VDC at 500+mA
under load, fed from a ridiculously variable input supply -
basically anything that can feed it enough juice to give the
required output - Batteries, solar cells, a mini-windmill, a DC
motor spun-to-operate-as-a-generator - whatever.

As currently envisioned, I'm thinking of feeding it using a
scavenged stepper motor that used to operate the tractor-feed of an
old line printer - The unit I have in mind is labeled as wanting
40VDC at 10 amps, and after some creative wiring for testing, I've
found that spinning it with fingers gets it to put out an extremely
"wobbly" (and noisy as hell when looked at with an o-scope) 6-25
volts, with no idea what the amperage is - suspect it's probably
pushing "a couple amps", give or take. (Yeah, I know... working to
such close tolerances is a real pain in the arse )

I figure to mount it on a little push-cart I use frequently,
friction-coupled to one of the wheels, MAYBE through a gear-train to
bump up the RPMs. Ultimate goal: Charge/operate an
iPod/iPhone/similar usually-USB-powered toy without ever needing to
plug the unit into a "real" USB port.

Suggestions? Comments on feasibility? Diagnoses of my particular
mental aberration(s) and/or ideas for suitable medications to cure
it/them?

Yes, drive it with an electric drill so you can get a real idea of the
voltage and current the motor can produce as a generator.

--
Best Regards:
Baron.

 

[Reinhard Zwirner]

Ralph Mowery schrieb:

[...]

You can use a three terminal voltage regulator and a couple of capacitors.
Just search for a 7805 voltage regulator. It will take a voltage source
from about 7 volts to 35 volts and give you 5 volts out at up to around 1
amp.

But don't forget to use a large heatsink to prevent overheating in
case of a large difference between input and output voltage!

HTH

Reinhard

 

[Jasen Betts]

On 2015-03-06, Don Bruder <dakidd@sonic.net> wrote:

The goal:
A power supply that outputs a solidly regulated +5.0VDC at 500+mA under
load, fed from a ridiculously variable input supply - basically anything
that can feed it enough juice to give the required output - Batteries,
solar cells, a mini-windmill, a DC motor spun-to-operate-as-a-generator
- whatever.

As currently envisioned, I'm thinking of feeding it using a scavenged
stepper motor that used to operate the tractor-feed of an old line
printer

Suggestions? Comments on feasibility? Diagnoses of my particular mental
aberration(s) and/or ideas for suitable medications to cure it/them?

Permanent magnet altenators being inherently current-limited but not
voltage limited are often regulated using shunt regulators or by
short-circuiting the output.

--
umop apisdn