TEST EQUIPMENT

[Jennie]

Where is the cheapest and decent quality place to get a DC Power Supply?

 

[Jennie]

Student quality should be fine...


"Jennie" <hnix@adelphia.net> wrote in message
news:APKdnVXh8ena_fncRVn-ow@adelphia.com...

Where is the cheapest and decent quality place to get a DC Power Supply?

 

[mike]

Jennie wrote:

Where is the cheapest and decent quality place to get a DC Power Supply?

I'd go to Fry's and get a AA battery. Quite "decent". They're really
cheap when they're on sale...
unless you want a dfferent voltage, or variable, or more current or
current limited or metered or...or...or...all the things that you didn't
specify. Depending on where you're located, you may be across the
street or 5000 miles from a dealer.

It must be hard to ask a question that can be answered, cause so few do
it. :-(
mike

--
Return address is VALID.
Wanted, 12.1" LCD for Gateway Solo 5300. Samsung LT121SU-121
Wanted GPIB Card for PC.
Bunch of stuff For Sale and Wanted at the link below.
http://www.geocities.com/SiliconValley/Monitor/4710/

 

[Clarence]

"Jennie" <hnix@adelphia.net> wrote in message
news:APKdnVXh8ena_fncRVn-ow@adelphia.com...

Where is the cheapest and decent quality place to get a DC Power Supply?


Since you have not specified a particular voltage or current I will assume you

mean a metered, adjustable, bench supply.

There are many places but here is one with an array of possible.

http://www.mpja.com/

I am not affiliated with the company, but have made several purchases from them
with good results.

 

[John Fields]

On Wed, 6 Oct 2004 17:14:46 -0400, "Jennie" <hnix@adelphia.net> wrote:

Where is the cheapest and decent quality place to get a DC Power Supply?

---
Input voltage and frequency?

Single output?

Dual?

Triple?

Output voltage range?

Maximum output current?

Constant Voltage/Constant Current capability?

Current limiting capability?

Budget constraints?

--
John Fields

 

[nihoa]

"Jennie" <hnix@adelphia.net> wrote in message
news:APKdnVXh8ena_fncRVn-ow@adelphia.com...

Where is the cheapest and decent quality place to get a DC Power Supply?

Try Ebay.com. It seems like Ebay has tons of DC power supplies on auction.
I'm certain you can get a quality P.S. there for cheap.

 

[Jennie]

Just a single variable dc source up to 13 to 14 volts. Under 50..


"nihoa" <nihoa@swbell.net> wrote in message
news:qy_8d.3047$q%7.681@newssvr11.news.prodigy.com...

"Jennie" <hnix@adelphia.net> wrote in message
news:APKdnVXh8ena_fncRVn-ow@adelphia.com...
Where is the cheapest and decent quality place to get a DC Power Supply?



Try Ebay.com. It seems like Ebay has tons of DC power supplies on
auction.
I'm certain you can get a quality P.S. there for cheap.

 

[Jennie]

Thanks....

Just curious, if I hook up a led with 20mA to 3 AA battery how long will the
light stay lit?

Thanks

"Clarence" <no@No.com> wrote in message
news:6u09d.25013$QJ3.23604@newssvr21.news.prodigy.com...

"Jennie" <hnix@adelphia.net> wrote in message
news:7a2dnWzRNZTl5vncRVn-rw@adelphia.com...
Just a single variable dc source up to 13 to 14 volts. Under 50..


"nihoa" <nihoa@swbell.net> wrote in message
news:qy_8d.3047$q%7.681@newssvr11.news.prodigy.com...

"Jennie" <hnix@adelphia.net> wrote in message
news:APKdnVXh8ena_fncRVn-ow@adelphia.com...
Where is the cheapest and decent quality place to get a DC Power
Supply?



Try Ebay.com. It seems like Ebay has tons of DC power supplies on
auction.
I'm certain you can get a quality P.S. there for cheap.




NEW-Close @ $59.95 http://www.mpja.com/productview.asp?product=14600+PS

OR For $3.95 and shipping you can get a 24 volt 2 amp supply and put an
external regulator on it for 2.5 to 20 volts.
Add this kit for the adjustable output
http://www.electronics123.com/amazon/catalogue/c3-3-8.htm

This is the description
1.5 to 30V Adjustable Power Supply (picture)
This is a basic adjustable voltage power supply using the popular three
pin
regulator, LM317T. You can select any voltage between 1.5V and 30V using a
potentiometer. The LM317T is rated at 1.5A so you must use a larger heat
sink
when drawing high currents. Unregulated AC or DC input via terminal block
or
power jack. Requires a suitable transformer.
Documentation in acrobat format
Order Code: CPS68 (Basic Soldering-Kit) Price $9.95

Variable Supply 1.3 to 30V and 300mA to 1.5A (input 16VAC) (picture)
This is a basic adjustable voltage power supply using the three pin
regulator,
LM317T. Any voltage between 1.3V and 30V can be selected using a
potentiometer.
A current limiting circuit is also included that can limit the output
current
between 300mA and 1.5A. This feature is useful when current adjustment is
required in circuit development. The LM317T is rated at 1.5A so you must
use a
larger heat sink when drawing high currents. Unregulated AC or DC input
via a
terminal block. Requires a suitable transformer.
Input supply: 12 - 16 VAC (or 20V DC)
Output: 1.3 to 30V / 0.3 to 1.5A
PCB size: 50x37mm
Order Code: AA557 (Basic Soldering-Kit) Price $8.95



OR this kit MODEL XP-620K............KIT....$49.95*
from http://www.oselectronics.com/ose_p15.htm


More?

 

[Jennie]

What is the equation to figure out the time...

"Jennie" <hnix@adelphia.net> wrote in message
news:G7OdnURNX66RCPncRVn-gw@adelphia.com...

Thanks....

Just curious, if I hook up a led with 20mA to 3 AA battery how long will
the light stay lit?

Thanks

"Clarence" <no@No.com> wrote in message
news:6u09d.25013$QJ3.23604@newssvr21.news.prodigy.com...

"Jennie" <hnix@adelphia.net> wrote in message
news:7a2dnWzRNZTl5vncRVn-rw@adelphia.com...
Just a single variable dc source up to 13 to 14 volts. Under 50..


"nihoa" <nihoa@swbell.net> wrote in message
news:qy_8d.3047$q%7.681@newssvr11.news.prodigy.com...

"Jennie" <hnix@adelphia.net> wrote in message
news:APKdnVXh8ena_fncRVn-ow@adelphia.com...
Where is the cheapest and decent quality place to get a DC Power
Supply?



Try Ebay.com. It seems like Ebay has tons of DC power supplies on
auction.
I'm certain you can get a quality P.S. there for cheap.




NEW-Close @ $59.95 http://www.mpja.com/productview.asp?product=14600+PS

OR For $3.95 and shipping you can get a 24 volt 2 amp supply and put an
external regulator on it for 2.5 to 20 volts.
Add this kit for the adjustable output
http://www.electronics123.com/amazon/catalogue/c3-3-8.htm

This is the description
1.5 to 30V Adjustable Power Supply (picture)
This is a basic adjustable voltage power supply using the popular three
pin
regulator, LM317T. You can select any voltage between 1.5V and 30V using
a
potentiometer. The LM317T is rated at 1.5A so you must use a larger heat
sink
when drawing high currents. Unregulated AC or DC input via terminal block
or
power jack. Requires a suitable transformer.
Documentation in acrobat format
Order Code: CPS68 (Basic Soldering-Kit) Price $9.95

Variable Supply 1.3 to 30V and 300mA to 1.5A (input 16VAC) (picture)
This is a basic adjustable voltage power supply using the three pin
regulator,
LM317T. Any voltage between 1.3V and 30V can be selected using a
potentiometer.
A current limiting circuit is also included that can limit the output
current
between 300mA and 1.5A. This feature is useful when current adjustment is
required in circuit development. The LM317T is rated at 1.5A so you must
use a
larger heat sink when drawing high currents. Unregulated AC or DC input
via a
terminal block. Requires a suitable transformer.
Input supply: 12 - 16 VAC (or 20V DC)
Output: 1.3 to 30V / 0.3 to 1.5A
PCB size: 50x37mm
Order Code: AA557 (Basic Soldering-Kit) Price $8.95



OR this kit MODEL XP-620K............KIT....$49.95*
from http://www.oselectronics.com/ose_p15.htm


More?

 

[Clarence]

"Jennie" <hnix@adelphia.net> wrote in message
news:G7OdnURNX66RCPncRVn-gw@adelphia.com...

Thanks....

Just curious, if I hook up a led with 20mA to 3 AA battery how long will the
light stay lit?

Thanks

Depends on the battery, and the LED.
for ACCUPOWER "1000mAh" AAA Nimh cells it would be
1000 / .02 = 50 hours. However that does not allow for the voltage.
For a single led with a series resistor from .12 * 3 = 3.6 volts down to 2.7
volts.

If you have a RED LED which has an offset of 1.8 volts the resistor to limit
the current at full charge to 20ma is

( 3.6 volts - 1.8 V,LED) / .02 = 90 ohms. (2 each 180 ohm resistors in
parallel would be closest, but a 100 ohm 1/4 Resistor would be satisfactory, I
= .018 Amperes)

Power max = I^2 * R

..02^2 * 180. .072 W (1/4 watts resistors are fine.)

Note that as the battery becomes discharged the voltage drops.
I'll use .9 as a limit value. (Depends on the battery.)

2.7 - 1.8 = 10ma So the LED should be at half current when the Battery should
be recharged. You should not allow the LED to go out before recharging, you
may damage the battery.

Also. The Batteries self discharge over time, between charging. So the actual
time will vary some. Approximately 42 to 52 hours.

 

[Clarence]

"Jennie" <hnix@adelphia.net> wrote in message
news:G7OdnURNX66RCPncRVn-gw@adelphia.com...

Thanks....

Just curious, if I hook up a led with 20mA to 3 AA battery how long will the
light stay lit?

Thanks

Correction

Depends on the battery, and the LED.
for ACCUPOWER "1000mAh" AAA Nimh cells it would be
1.000 / .02 = 50 hours. However that does not allow for the
voltage.
For a single led with a series resistor from .12 * 3 = 3.6 volts
down to 2.7
volts.

Pesky little DP fell off.

 

[Jennie]

What book have all this good info in it?


"Clarence" <no@No.com> wrote in message
news:%m19d.25048$QJ3.211@newssvr21.news.prodigy.com...

"Jennie" <hnix@adelphia.net> wrote in message
news:G7OdnURNX66RCPncRVn-gw@adelphia.com...
Thanks....

Just curious, if I hook up a led with 20mA to 3 AA battery how long will
the
light stay lit?

Thanks

Correction

Depends on the battery, and the LED.
for ACCUPOWER "1000mAh" AAA Nimh cells it would be
1.000 / .02 = 50 hours. However that does not allow for the
voltage.
For a single led with a series resistor from .12 * 3 = 3.6 volts
down to 2.7
volts.


Pesky little DP fell off.

 

[Clarence]

"Jennie" <hnix@adelphia.net> wrote in message
news:nbqdnbg8tLjpOvncRVn-pg@adelphia.com...

What book have all this good info in it?

There are many, I'm sure. But I didn't use a book. Been doing this sort of
thing for decades.

Might try the Radio Amateurs Handbook. It is good on basic electronics. Then
there is Horowitz and Hill "The Art of Electronics." but it is rather large.
There are many texts on basic electronics available. I usually just open one
of my Engineering handbooks when I have a question. They are all getting
pretty old.

"Clarence" <no@No.com> wrote in message
news:%m19d.25048$QJ3.211@newssvr21.news.prodigy.com...
"Jennie" <hnix@adelphia.net> wrote in message
news:G7OdnURNX66RCPncRVn-gw@adelphia.com...
Thanks....
Just curious, if I hook up a led with 20mA to 3 AA battery how long will
the light stay lit?
Thanks

Correction
Depends on the battery, and the LED.
for ACCUPOWER "1000mAh" AAA Nimh cells it would be
1.000 / .02 = 50 hours. However that does not allow for the
voltage.
For a single led with a series resistor from .12 * 3 = 3.6 volts
down to 2.7
volts.
Pesky little DP fell off.

 

[Robert Baer]

Jennie wrote:

Where is the cheapest and decent quality place to get a DC Power Supply?

Youse gots tah sey what youse kneeds more better.
What voltage, adjustable or fixed, what current capability, current
limiting?, adjustable current limiting? meters?
Be eXplicit!

 

[Clarence]

"Robert Baer" <robertbaer@access4less.net> wrote in message
news:4164F4D8.5090907@access4less.net...

Jennie wrote:

Where is the cheapest and decent quality place to get a DC Power Supply?




You Have to say what you need.
What voltage, adjustable or fixed, what current capability, current
limiting?, adjustable current limiting? meters?
Be explicit!

She was quite definite on the price, and the basic voltage adjustment range.

You, on the other-hand are impossible to decipher. (Spelling corrected.)