power supply explanation

F

F Murtz

Guest
This news group business is a hard path to tread what with cranky
australians and americans with money and magical Radio Shacks that have
just what you want.
Most of the replies were courteous and may have been helpful if I were
into design
My existing power supply I made over fourty years ago with some ca130 op
amps and a 3055.
I did not design the circuit [it came from radio and hobbies or
electronics australia or some such magazine]
I wound the transformer myself on c laminations [I had access to a
winding shop then].
I etched the circuit board myself made my own case out of sheet steel
Calibrated my own meter face.Only paid for components.
It was 0-20 V and 0-2.5 A [you could choose volts or amps to control]
I have lost this circuit and this power supply is starting to become
unstable so I thought now would be the time to make something beefier.
As you can gather I like making things myself from scratch
Perhaps I was silly thinking newsgroups might be where I might find some
clues to a suitable circuit
 
Perhaps I was silly thinking newsgroups might be where I might find some
clues to a suitable circuit
Click to expand...
Specific circuits are generally hard to come by on the internet.

Just google "circuit variable voltage supply" and you will probably find
everything there is. Trying to make your own variable voltage supply is
pretty uncommon these days, considering you can by them for $50 - $100.
 
MisterE wrote:
Perhaps I was silly thinking newsgroups might be where I might find some
clues to a suitable circuit

Specific circuits are generally hard to come by on the internet.

Just google "circuit variable voltage supply" and you will probably find
everything there is. Trying to make your own variable voltage supply is
pretty uncommon these days, considering you can by them for $50 - $100.


I was trying for controlled current and controlled voltage regulation my
Click to expand...
old one had switch so that you could vary the current drawn using a pot
or the voltage from a different pot if the switch was the other way. The
regulated bench power supplies of 0to 20 or 30v up to 4A seem to be $200
or more
 
MisterE wrote:
Perhaps I was silly thinking newsgroups might be where I might find some
clues to a suitable circuit

Specific circuits are generally hard to come by on the internet.

Just google "circuit variable voltage supply" and you will probably find
everything there is. Trying to make your own variable voltage supply is
pretty uncommon these days, considering you can by them for $50 - $100.
Click to expand...

I have found a circuit which might do me

http://www.electronics-lab.com/projects/power/003/index.html
 
----- Original Message -----
From: "F Murtz" <haggisz@hotmail.com>
Newsgroups:
aus.electronics,alt.binaries.schematics.electronic,sci.electronics.basics
Sent: Wednesday, June 11, 2008 3:57 AM
Subject: power supply explanation


This news group business is a hard path to tread what with cranky
australians
Click to expand...
We shall not name any names, of course! ;)

and americans with money and magical Radio Shacks that have just what you
want.
Click to expand...
Perhaps at one time they did. Not any more.

Most of the replies were courteous and may have been helpful if I were
into design
My existing power supply I made over fourty years ago with some ca130 op
amps and a 3055.
I did not design the circuit [it came from radio and hobbies or
electronics australia or some such magazine]
I wound the transformer myself on c laminations [I had access to a winding
shop then].
I etched the circuit board myself made my own case out of sheet steel
Calibrated my own meter face.Only paid for components.
It was 0-20 V and 0-2.5 A [you could choose volts or amps to control]
I have lost this circuit and this power supply is starting to become
unstable so I thought now would be the time to make something beefier.
As you can gather I like making things myself from scratch
Perhaps I was silly thinking newsgroups might be where I might find some
clues to a suitable circuit
Click to expand...
I'm not familiar with power supplies that have separate controls for voltage
and current regulation, where you would have to disable voltage regulation
in order to achieve current control (limiting). You don't really need such
a switch for most applications.
Consider the standard, voltage-regulated, current-limited power supply:
when current reaches the setpoint and the current-limiting loop kicks in,
voltage regulation gets cut out of the loop anyway. So why have a switch?
Here's an example of a voltage regulator with current limiting:
http://www.rason.org/Projects/discreg/discreg.htm
His claims for "performance" are a bit exaggerated. I think you might get
better line regulation and a flatter temperature response with an LM317 or
LM723.
This link goes over the fundamentals of linear voltage regulation pretty
well:
http://www.national.com/appinfo/power/files/f4.pdf


** Posted from http://www.teranews.com **
 
"Michael Robinson"
This news group business is a hard path to tread what with cranky
australians

We shall not name any names, of course! ;)
Click to expand...

** The *** OP *** is a cranky Australian.

Plus an asinine PITA smug ungrateful troll !!!

Here is the same asses post on " aus.legal " today:

" court case aborted when jurors played sidoku what if jurors do complex
calculus in their head? "


Yep - that is the whole damn post and the original post of a new thread.

Got a clue what mental defect this wanker has ?




...... Phil
 
On Wed, 11 Jun 2008 20:57:56 +1000, F Murtz <haggisz@hotmail.com>
wrote:

This news group business is a hard path to tread what with cranky
australians and americans with money and magical Radio Shacks that have
just what you want.
Most of the replies were courteous and may have been helpful if I were
into design
My existing power supply I made over fourty years ago with some ca130 op
amps and a 3055.
I did not design the circuit [it came from radio and hobbies or
electronics australia or some such magazine]
I wound the transformer myself on c laminations [I had access to a
winding shop then].
I etched the circuit board myself made my own case out of sheet steel
Calibrated my own meter face.Only paid for components.
It was 0-20 V and 0-2.5 A [you could choose volts or amps to control]
I have lost this circuit and this power supply is starting to become
unstable so I thought now would be the time to make something beefier.
As you can gather I like making things myself from scratch
Perhaps I was silly thinking newsgroups might be where I might find some
clues to a suitable circuit
Click to expand...
I'd be tempted to repair the old circuit, first. Things like pots,
caps and switches do eventually wear out, and it's simpler fixing
something you're familiar with. The 3130/3140 is still alive and well
as a replacement part, from distributors like DigiKey. It wouldn't be
the first suspect in troubleshooting flakey behavior, though.

You might be surprized just how similar your old circuit is to the new
kit you've found. Beefing your old circuit up might simply involve
changing a few components and adding a larger heatsink.

RL
 
Michael Robinson wrote:
----- Original Message -----
From: "F Murtz" <haggisz@hotmail.com
Newsgroups:
aus.electronics,alt.binaries.schematics.electronic,sci.electronics.basics
Sent: Wednesday, June 11, 2008 3:57 AM
Subject: power supply explanation


This news group business is a hard path to tread what with cranky
australians

We shall not name any names, of course! ;)

and americans with money and magical Radio Shacks that have just what you
want.

Perhaps at one time they did. Not any more.

Most of the replies were courteous and may have been helpful if I were
into design
My existing power supply I made over fourty years ago with some ca130 op
amps and a 3055.
I did not design the circuit [it came from radio and hobbies or
electronics australia or some such magazine]
I wound the transformer myself on c laminations [I had access to a winding
shop then].
I etched the circuit board myself made my own case out of sheet steel
Calibrated my own meter face.Only paid for components.
It was 0-20 V and 0-2.5 A [you could choose volts or amps to control]
I have lost this circuit and this power supply is starting to become
unstable so I thought now would be the time to make something beefier.
As you can gather I like making things myself from scratch
Perhaps I was silly thinking newsgroups might be where I might find some
clues to a suitable circuit

I'm not familiar with power supplies that have separate controls for voltage
and current regulation, where you would have to disable voltage regulation
in order to achieve current control (limiting). You don't really need such
a switch for most applications.
the switch on my old supply controlled weather current or voltage were
Click to expand...
controlling. the meter showed either current or voltage depending on the
switch. The potentiometers controlled the current or voltage ie if the
current was set at say .5 amps then that is the current regardless of
where the voltage pot was unless it was too low. The voltage was limited
for that current
Visa versa if the switch was other way


Consider the standard, voltage-regulated, current-limited power supply:
when current reaches the setpoint and the current-limiting loop kicks in,
voltage regulation gets cut out of the loop anyway. So why have a switch?
Here's an example of a voltage regulator with current limiting:
http://www.rason.org/Projects/discreg/discreg.htm
His claims for "performance" are a bit exaggerated. I think you might get
better line regulation and a flatter temperature response with an LM317 or
LM723.
This link goes over the fundamentals of linear voltage regulation pretty
well:
http://www.national.com/appinfo/power/files/f4.pdf


** Posted from http://www.teranews.com **
Click to expand...
 
On Wed, 11 Jun 2008 05:39:12 -0700, "Michael Robinson" <kellrobinson
"at the Y"> wrote:


I'm not familiar with power supplies that have separate controls for voltage
and current regulation, where you would have to disable voltage regulation
in order to achieve current control (limiting).
Click to expand...
---
They're common, and usually called CV/CC supplies:

http://www.alliancetesteq.com/pdf/agilent_hp_6216a.pdf

If you want voltage regulation you start with both controls at zero
and the switch set to VOLTAGE, then you crank the current switch to
max and adjust the voltage control for the output voltage you want.
The current into the load will then vary as required in order to keep
the output voltage constant.

If you want current regulation then you start with both controls at
zero and the switch set to CURRENT, then you crank the voltage control
to max and adjust the current control for the output current you want.
The voltage across the load will then vary as required to keep the
current through it constant.

If you want current or voltage limiting, then you set the appropriate
control to the limit it shouldn't exceed.

You don't really need such a switch for most applications.
Click to expand...
---
If you have a CV/CC supply then you certainly do. How else would you
switch between Constant Voltage and Constant Current modes?


JF
 
On Wed, 11 Jun 2008 09:05:54 -0500, John Fields
<jfields@austininstruments.com> wrote:

On Wed, 11 Jun 2008 05:39:12 -0700, "Michael Robinson" <kellrobinson
"at the Y"> wrote:


I'm not familiar with power supplies that have separate controls for voltage
and current regulation, where you would have to disable voltage regulation
in order to achieve current control (limiting).

---
They're common, and usually called CV/CC supplies:

http://www.alliancetesteq.com/pdf/agilent_hp_6216a.pdf

If you want voltage regulation you start with both controls at zero
and the switch set to VOLTAGE, then you crank the current switch to
max and adjust the voltage control for the output voltage you want.
The current into the load will then vary as required in order to keep
the output voltage constant.

If you want current regulation then you start with both controls at
zero and the switch set to CURRENT, then you crank the voltage control
to max and adjust the current control for the output current you want.
The voltage across the load will then vary as required to keep the
current through it constant.

If you want current or voltage limiting, then you set the appropriate
control to the limit it shouldn't exceed.

You don't really need such a switch for most applications.

---
If you have a CV/CC supply then you certainly do. How else would you
switch between Constant Voltage and Constant Current modes?
Click to expand...
---
Oops...

You don't need the switch to change modes, it's just there to switch
from ammeter to voltmeter.


JF
 
On Wed, 11 Jun 2008 22:55:08 +1000, "Phil Allison"
<philallison@tpg.com.au> wrote:

"Michael Robinson"

This news group business is a hard path to tread what with cranky
australians

We shall not name any names, of course! ;)


** The *** OP *** is a cranky Australian.

Plus an asinine PITA smug ungrateful troll !!!

Here is the same asses post on " aus.legal " today:

" court case aborted when jurors played sidoku what if jurors do complex
calculus in their head? "


Yep - that is the whole damn post and the original post of a new thread.

Got a clue what mental defect this wanker has ?




..... Phil




PHil, You having a Midol minute?
Click to expand...
 
On Wed, 11 Jun 2008 20:57:56 +1000, F Murtz wrote:

This news group business is a hard path to tread what with cranky
australians and americans with money and magical Radio Shacks that have
just what you want.
Most of the replies were courteous and may have been helpful if I were
into design
My existing power supply I made over fourty years ago with some ca130 op
amps and a 3055.
I did not design the circuit [it came from radio and hobbies or
electronics australia or some such magazine] I wound the transformer
myself on c laminations [I had access to a winding shop then].
I etched the circuit board myself made my own case out of sheet steel
Calibrated my own meter face.Only paid for components. It was 0-20 V and
0-2.5 A [you could choose volts or amps to control] I have lost this
circuit and this power supply is starting to become unstable so I
thought now would be the time to make something beefier. As you can
gather I like making things myself from scratch Perhaps I was silly
thinking newsgroups might be where I might find some clues to a suitable
circuit
Click to expand...
Well, I _did_ suggest that you check out the ARRL Handbook, which has a
nice adjustable supply project with pretty much those specifications or
better. I don't know how hard it'd be to get one in Oz, but certainly it
isn't impossible.

And if Radio Shack has more for it than the bannana jacks and some
overpriced, underperforming meters, I'd be surprised.

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html
 
"Tim Wescott" <tim@seemywebsite.com> wrote in message
news:ENKdneFGeJN-ZtLVnZ2dnUVZ_hqdnZ2d@web-ster.com...
And if Radio Shack has more for it than the bannana jacks and some
overpriced, underperforming meters, I'd be surprised.
Click to expand...
Radio Shack rescues me regularly. My local one has a nice supply of
overpriced transistors, LEDs, switches, relays, connectors, etc, all stored
neatly in extremely nice metal drawers, and a bunch of sales people who try
to sell me cell phones and radio controlled cars. However, when I need a
widget, and don't want to drive to Frys or wait for mail order, it
occasionally has what I need.

Regards,
Bob Monsen
 
"Bob Monsen" <rcmonsen@gmail.com> wrote in message
news:aLT3k.11467$Ri.3666@flpi146.ffdc.sbc.com...
"Tim Wescott" <tim@seemywebsite.com> wrote in message
news:ENKdneFGeJN-ZtLVnZ2dnUVZ_hqdnZ2d@web-ster.com...
And if Radio Shack has more for it than the bannana jacks and some
overpriced, underperforming meters, I'd be surprised.

Radio Shack rescues me regularly. My local one has a nice supply of
overpriced transistors, LEDs, switches, relays, connectors, etc, all
stored neatly in extremely nice metal drawers, and a bunch of sales people
who try to sell me cell phones and radio controlled cars. However, when I
need a widget, and don't want to drive to Frys or wait for mail order, it
occasionally has what I need.

Regards,
Bob Monsen
Click to expand...
Yep. I agree. In SoCal, Frys is about the best place that you can still
drive to and get parts, but Radio Shack still can be useful certain ICs,
transistors, leds, switches, connectors, and cheap/inexpensive project
boxes. Of course, neither compares to Digikey.

Bob
--
== NOTE: I automatically delete all Google Group posts due to uncontrolled
SPAM ==
 
F Murtz wrote:

this power supply is starting to become unstable
Click to expand...
Some caps (electrolytics) are likely at their end of life. Just replace
them.

Graham
 
On Wed, 11 Jun 2008 20:57:56 +1000, F Murtz <haggisz@hotmail.com>
wrote:

This news group business is a hard path to tread what with cranky
australians and americans with money and magical Radio Shacks that have
just what you want.
Most of the replies were courteous and may have been helpful if I were
into design
My existing power supply I made over fourty years ago with some ca130 op
amps and a 3055.
I did not design the circuit [it came from radio and hobbies or
electronics australia or some such magazine]
I wound the transformer myself on c laminations [I had access to a
winding shop then].
I etched the circuit board myself made my own case out of sheet steel
Calibrated my own meter face.Only paid for components.
It was 0-20 V and 0-2.5 A [you could choose volts or amps to control]
I have lost this circuit and this power supply is starting to become
unstable so I thought now would be the time to make something beefier.
As you can gather I like making things myself from scratch
Perhaps I was silly thinking newsgroups might be where I might find some
clues to a suitable circuit
Click to expand...

Step by step uA723 regulator.

http://www.uoguelph.ca/~antoon/circ/ps3010/ps3010a.html
 
"BobW" <nimby_NEEDSPAM@roadrunner.com> wrote in message
news:AYSdnUCg1NS_kM3VnZ2dnUVZ_h_inZ2d@giganews.com...
"Bob Monsen" <rcmonsen@gmail.com> wrote in message
news:aLT3k.11467$Ri.3666@flpi146.ffdc.sbc.com...
"Tim Wescott" <tim@seemywebsite.com> wrote in message
news:ENKdneFGeJN-ZtLVnZ2dnUVZ_hqdnZ2d@web-ster.com...
And if Radio Shack has more for it than the bannana jacks and some
overpriced, underperforming meters, I'd be surprised.

Radio Shack rescues me regularly. My local one has a nice supply of
overpriced transistors, LEDs, switches, relays, connectors, etc, all
stored neatly in extremely nice metal drawers, and a bunch of sales
people who try to sell me cell phones and radio controlled cars. However,
when I need a widget, and don't want to drive to Frys or wait for mail
order, it occasionally has what I need.

Regards,
Bob Monsen


Yep. I agree. In SoCal, Frys is about the best place that you can still
drive to and get parts, but Radio Shack still can be useful certain ICs,
transistors, leds, switches, connectors, and cheap/inexpensive project
boxes. Of course, neither compares to Digikey.

Bob
--
Click to expand...

Maplin in the UK nowadays.

Chris

--
 
On 11 Jun, 14:27, F Murtz <hagg...@hotmail.com> wrote:

the switch on my old supply controlled weather current
Click to expand...
Did it do that come rain or shine?
 
On Wed, 11 Jun 2008 20:57:56 +1000, F Murtz <haggisz@hotmail.com> wrote:

This news group business is a hard path to tread what with cranky
australians and americans with money and magical Radio Shacks that have
just what you want.
Most of the replies were courteous and may have been helpful if I were
into design
My existing power supply I made over fourty years ago with some ca130 op
amps and a 3055.
I did not design the circuit [it came from radio and hobbies or
electronics australia or some such magazine]
I wound the transformer myself on c laminations [I had access to a
winding shop then].
I etched the circuit board myself made my own case out of sheet steel
Calibrated my own meter face.Only paid for components.
It was 0-20 V and 0-2.5 A [you could choose volts or amps to control]
I have lost this circuit and this power supply is starting to become
unstable so I thought now would be the time to make something beefier.
As you can gather I like making things myself from scratch
Perhaps I was silly thinking newsgroups might be where I might find some
clues to a suitable circuit
Click to expand...

It all sounds great.

One thing though... how could you possibly expect to get an optimized
power supply design by giving some arbitrary, not-quite-all-informative
description of a couple of transformers?

Common sense should tell one that it would be easier, less costly on
time and money, and better to start from the ground up.

Hell, you claim no fancy stores... I'll bet that you haven't looked for
surplus or the like. There are usually those in any given town of any
significant size anywhere in the world. If you have power, you likely
have someone there running a store that has gear he collected in it.

Then, of course, there are all kinds of hobbyist stores online.

The learning kits... everything is all there.


Essentially, your question was simply to vague to give the answer you
seem to have been wanting to it.

A $25 class D audio amp can be used as the driver front end to an
infinitely variable, variable frequency, power supply.

You need to decide what voltage range and power range you want to
operate in, and with that info, you can deduce what your power needs will
be to achieve such a supply.

Then, there are noise considerations. Simple regulated supplies
typically have a very high ripple figure and are not useable in some
digital domains. There are also switchers that are "noisy" in some
niches of the industry (HF transceivers, etc.).

So, your request was oversimplified, so any answer you would have
gotten would have been just as simple in nature.

The smack across the face you got from a couple folks was a wake up and
use some sense call. Consider this one to be similar in nature.

All drawn out... whoopie doo.

The smack down worked as well.
 
Bob Monsen wrote:
"Tim Wescott" <tim@seemywebsite.com> wrote in message
news:ENKdneFGeJN-ZtLVnZ2dnUVZ_hqdnZ2d@web-ster.com...
And if Radio Shack has more for it than the bannana jacks and some
overpriced, underperforming meters, I'd be surprised.

Radio Shack rescues me regularly. My local one has a nice supply of
overpriced transistors, LEDs, switches, relays, connectors, etc, all
stored neatly in extremely nice metal drawers, and a bunch of sales
people who try to sell me cell phones and radio controlled cars.
However, when I need a widget, and don't want to drive to Frys or wait
for mail order, it occasionally has what I need.

Regards,
Bob Monsen

Me, too -- but they don't have _everything_.
Click to expand...

I was in there last night buying jumpers, and it occurred to me that you
could build entire amateur radio transceivers just from Rat-Shack parts
and some creativity. It would be a cool contest, if you had the time.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html
 
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