### Network

G

#### Gary Lecomte

Jan 1, 1970
0
This is a Voltage and Current Regulated Supply with the ability to go
to down to Zero Volts. It is not super Quality, but Definately good
for Beginners or anyone wanting a Simple Design.
So, If interested in a Reasonably Good, but Simple Power Supply
Project and a
(Also Mailed Free of Charge to the winner)
Go to: http://www3.telus.net/chemelec/Projects/Projects.htm

For Details, Click on the "Power Supply" Project.

Take care......Gary

M

#### mike

Jan 1, 1970
0
Gary said:
This is a Voltage and Current Regulated Supply with the ability to go
to down to Zero Volts. It is not super Quality, but Definately good
for Beginners or anyone wanting a Simple Design.
So, If interested in a Reasonably Good, but Simple Power Supply
Project and a
(Also Mailed Free of Charge to the winner)
Go to: http://www3.telus.net/chemelec/Projects/Projects.htm

For Details, Click on the "Power Supply" Project.

Take care......Gary

Why would you want to reverse bias a tantalum cap???
mike

--
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Honda CB-125S $800 in PDX Yaesu FTV901R Transverter, 30pS pulser Tektronix Concept Books, spot welding head... http://www.geocities.com/SiliconValley/Monitor/4710/ G #### Gary Lecomte Jan 1, 1970 0 mike said: Why would you want to reverse bias a tantalum cap??? mike Where did I do That? I don't see it. Gary K #### Ken Taylor Jan 1, 1970 0 Gary Lecomte said: Where did I do That? I don't see it. Gary Nor do I. I would like to see a few 0.1uF cap's at input and output of the reg IC's though. Cheers. Ken G #### Gary Lecomte Jan 1, 1970 0 Ken Taylor said: Nor do I. I would like to see a few 0.1uF cap's at input and output of the reg IC's though. Cheers. Ken Hi Ken, I tend to use 1 uF tantalums as I have thousands of them and find they work quite well. But if you wish to Substitute .1 uF caps in place of some or all of them, they will work as well, Maybe better in RF Situations. There are Improvements that can be made, but This is definately close to a Minimum Parts count for a supply that is both current and voltage regulated as well as the ability to go down to Zero volts. Great for the Beginner. This design is not totally unique, but better than most I have seen on the net. My hope is it is Cost Effective and Useful to some of these persons. Take care.......Gary Take care.........Gary M #### mike Jan 1, 1970 0 Gary said: Where did I do That? I don't see it. Gary This group seems to like "where's waldo" types of exercises. If nobody else finds it, I'll post what I think. Maybe I'm wrong... Hint: There are only four places to look. How hard can that be? ;-) Just curious about the current limit behavior. I'm kinda worried about what happens when the input voltage to the second IC drops below what it takes to make the chip work. How's the transient response in and out of current limit? Try a plethora of load lines and rep rates on your transient generator. mike -- Return address is VALID. Bunch of stuff For Sale and Wanted at the link below. Toshiba & Compaq LiIon Batteries, Test Equipment Honda CB-125S$800 in PDX
Yaesu FTV901R Transverter, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/

W

#### Walter Harley

Jan 1, 1970
0
Gary Lecomte said:
Where did I do That? I don't see it.

Take a look at what happens when your variable resistor is set to 0.

R

#### Ryan

Jan 1, 1970
0
Where did I do That? I don't see it.

Gary

In order for the output to get to 0 V the adj lead must be -1.25 V
with respect to ground. This reverse biases the cap on the adj lead.
Use a ceramic here.

Ryan

K

#### Ken Taylor

Jan 1, 1970
0
Gary Lecomte said:
Hi Ken, I tend to use 1 uF tantalums as I have thousands of them and
find they work quite well. But if you wish to Substitute .1 uF caps in
place of some or all of them, they will work as well, Maybe better in
RF Situations.

There are Improvements that can be made, but This is definately close
to a Minimum Parts count for a supply that is both current and voltage
regulated as well as the ability to go down to Zero volts. Great for
the Beginner.

This design is not totally unique, but better than most I have seen on
the net.

My hope is it is Cost Effective and Useful to some of these persons.

Take care.......Gary
Take care.........Gary

I'm seeing double today!

Check the spec's for the beast - you should use 0.1's as well as a tantalum.
Nice pick-up Mike, I'm flat out reading that late at night, let alone
interpreting!

Ken

W

#### Watson A.Name \Watt Sun - the Dark Remover\

Jan 1, 1970
0
Ken Taylor wrote:
[snip]
Nor do I. I would like to see a few 0.1uF cap's at input and output of the
reg IC's though.

Looks to me as if the 1 uF tantalum from the ADJ terminal to ground is
seeing anything from the max V minus 1.2V, all the way down to neg 1.2V.
So this cap had better be non-polarized.

G

#### Gary Lecomte

Jan 1, 1970
0
Walter Harley said:
Take a look at what happens when your variable resistor is set to 0.

OK, I see, but after 2 days it didn't affect it and a good portion of
the time it was at zero. In any case, that tantalum, or all of them
can be replaced with .1 uF caps.

Gary

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