Dropping 1V from a Regulated 6V Wall Wart

[John Woodgate]

I read in alt.binaries.schematics.electronic that Watson A. Name - Watt
Sun, Dark Remover <alondra101@hotmail.com> wrote (in <MPG.1a5cbb112ab587
88989ae1@news.dslextreme.com&gt about 'Dropping 1V from a Regulated 6V
Wall Wart', on Wed, 31 Dec 2003:

I talked about the weird connector,
someone said it's a Belling Lee connector,

That's a coaxial connector, a bit like a phono plug but with a smaller
centre pin. Is that what you have?

AKA Euro or PAL connector.

I'd forget those descriptions if I were you. Certainly the Belling
connector has very little indeed to do with PAL. It is the subject of an
IEC standard - IEC 60169-2.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

 

[Winfield Hill]

Watson A.Name - Watt Sun, Dark Remover wrote:
I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so
I tried a 3 amp rectifier, but it varied by more than .2V over
a range of loads. So I tried this: (view with courier font)

+ From wall [edited for brevity]
wart >--+---+-----+
| |
| |
400 \ / 2SC2334 or TIP31
ohm / |/ NPN power TO-220
WW \<-----| Heatsink optional
pot / |\
| E\
| |
| |
+----+----+----> + output
to load
- >-----------------> -

Hmm, a complementary-darlington emitter-follower transistor would
be less sensitive to changes in load current:

: +6.0V, from wall wart
: >--+--------+------+
: | | |
: | 220 | Q1 2sa1011
: | | |/E pnp TIP32
: | +----| etc
: | | |\
: 1.0k |/ |
: pot <---| Q2 |
: | |\E npn |
: | | |
: 7.5k +------+-----> + output
: | to load
: - >--+---------------------> -

Here the Q2 voltage drop is much more predictable, because it has a
relatively steady current set by Q1's base-emitter resistor, which
has about 0.55 to 0.75V across it despite output load changes. The
Q2 current is about 3 - 5mA and we expect a Vbe drop of about 700mV.
The lower end of the pot sits at about 5.3 volts.

The most serious problem with this circuit is its complete reliance
on a possibly-uncertain input voltage; the output will track any
changes in input.

nospam@nospam.com analyzed Watson A. Name's circuit:

You almost had it- put the Vbe multiplier inside the feedback
loop and buffer like so:

6V >---+------+-------+ [edited for brevity]
| | |
| 22 c
| | |/ Q1
| +-----| TIP31
| | |\
== | e---+----+----> 5V
| c Q2 | |
| \| / |
| |-------> \ |
| /| / ===
| e | 1000U
| | | |
GND >--+------+-----------+----+----> GND

Watson A.Name - Watt Sun, Dark Remover asked:

I'll toss one together, but what value should I use for the Pot?
10k? Lower?

This looks a lot like the current limiter circuit, 'cept for the pot.

No, it's an ordinary regulator, using Q2's Vbe (roughly 0.7V) as a
voltage reference. The pot as shown would be a poor choice because
valid adjustments would only use a small part of the pot's range.
No doubt nospam knew that and was just simplifying his drawing by
using one part instead of three. This should work; the top of the
pot has about 0.82V when the regulator is calibrated for 5V out:

| | ---+----> 5V
| | |
=== | ,-2k2--+
| c Q2 | |
| \| 100R |
| |----> pot |
| /| | ===
| e 330 1000U
| | | |
GND >--+------+---------+------+----> GND

This circuit has several problems. The tempco of Vbe is bad, but
the uncertain current through Q2 an even worse problem. This is
because the voltage difference between the +6V input and Q1's base
is small (and may vary widely), and Q1's base current is unknown.
If Q2's current changes by a factor of 10, its Vbe will change by
about 60mV, or nearly 10% of its value. As a result Q2 makes a
poor voltage reference in this circuit, even if manually adjusted.

I'm wondering if it's such a good idea to have such a large cap on
the output. When the wall wart is powered off, all that current
tries to go backwards thru the pass transistor.

A big cap is fine, maybe even necessary in that location, because a
small output cap could make the feedback loop unstable. We discuss
this issue in AoE and call it brute-force compensation.

The current won't go backwards for several reasons. The wall wort
probably doesn't draw output terminal current when the AC is off.
If it wanted to, Q1's Veb breakdown would certainly be above 5V so
no current would flow anyway.

Jim Thompson wrote...

Try this...

+ From wall [edited for brevity]
wart >--+---+-----+
| |
20 Q1 |
| / 2SC2334 or TIP31
| |/ NPN power TO-220
o------| Heatsink optional
| |\
| E\
| |
| o-----> + output
| | to load
__|___/ 2.2k
/ /\ |
/ \-------o
/ \ |
-------- 2.7k
| TL430 |
| |
- >------o---------o------> -

You may need a compensation cap between cathode and control pin.

This is a much better approach, using TL430's 2.75V reference with
a built-in error amplifier. The more popular TL431 can be used with
its 2.50V ref if the feedback-sensing resistors are the same value.

But I'm not happy with the output emitter follower in the circuits
above, because the low Vin - Vout difference leads to such widely-
varying currents through the control element. Perhaps my circuit
can be combined with Jim's circuit:

: +6.0V, from wall wart
: >--+------+------+
: | | |
: | 220 | Q1 2sa1011
: | | |/E pnp TIP32
: 750 +----| etc
: | | |\
: | |/ |
: +----| Q2 |
: | |\E npn |
: | | |
: | +---+--+----> + output

| | to load
__|___/ 2.7k
/ /\ |
/ \--------o
/ \ |
-------- 2.7k
| TL431 |
| |
- >----o----------o-------> -

Thanks,
- Win

whill_at_picovolt-dot-com

 

[Winfield Hill]

Winfield Hill wrote...

Perhaps my circuit can be combined with Jim's circuit:

: +6.0V, from wall wart
: >--+------+------+
: | | |
: | 220 | Q1 2sa1011
: | | |/E pnp TIP32
: 750 +----| etc
: | | |\
: | |/ |
: +----| Q2 |
: | |\E npn |
: | | |
: | +---+--+----> + output
| | to load
__|___/ 2.7k
/ /\ |
/ \--------o
/ \ |
-------- 2.7k
| TL431 |
| |
- >----o----------o-------> -

I'm still not happy with the poor dropout-voltage capability of
this circuit. It should be able to operate with Vin much closer
to Vout. Aha! Simply adding a diode and resistor lets us reduce
the dropout voltage down to near the saturation voltage of Q1.

: +5.3 to 9V
: >--+-----+------, SIMPLE 5.0V REGULATOR
: | | |
: | 220 | Q1 2sa1011
: | | |/E pnp TIP32
: 470 o----| etc
: | | |\
: | |/ |
: o---| Q2 '----o----> +5.0V
: | |\E npn | output
: | | | to load
: | | 1n4148 |
: | '--o--|<|---o

| | |
__|___/ 1k 2.7k
/ /\ | |
/ \----- | -------o
/ \ | |
-------- | 2.7k
| TL431 | |
| | |
- >----o--------o--------o----> -

Of course, an even more simple circuit is possible, using one
of the many low-cost low-dropout three-terminal regulator ICs.

: +5.3 to 9V etc
: >-------, EVEN MORE SIMPLE 5.0V REGULATOR
: __|__
: | |
: | |---+---> +5.0V
: |_____| _|_ output
: | --- to load
: | |
: - >-------o------o---> -

But this circuit isn't as much fun. :&gt

Thanks,
- Win

whill_at_picovolt-dot-com

 

[Watson A.Name - "Watt Sun]

In article <buCzdbCu7c8$EwFA@jmwa.demon.co.uk>,
jmw@jmwa.demon.contraspam.yuk mentioned...

I read in sci.electronics.design that Active8 <mTHISREMOVEcolasono@earth
link.net> wrote (in <MPG.1a5b77d1462634059897b9@news.west.earthlink.net
) about 'Dropping 1V from a Regulated 6V Wall Wart', on Tue, 30 Dec
2003:
Ok, I incorrectly guessed Beta (Chaos Master told me how to get
special characters and it doesn't work here)

Doesn't ALT0223 on the numeric keypad, with Num Lock on, work?
ßßß

This alt 0233 --> é looks to me like it's an accented e, as in Jose'
What's it look like to you?

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Active8]

On Wed, 31 Dec 2003 14:29:34 -0800, Watson A.Name - "Watt Sun, Dark
Remover" <alondra101@hotmail.com> said...

In article <buCzdbCu7c8$EwFA@jmwa.demon.co.uk>,
jmw@jmwa.demon.contraspam.yuk mentioned...
I read in sci.electronics.design that Active8 <mTHISREMOVEcolasono@earth
link.net> wrote (in <MPG.1a5b77d1462634059897b9@news.west.earthlink.net
) about 'Dropping 1V from a Regulated 6V Wall Wart', on Tue, 30 Dec
2003:
Ok, I incorrectly guessed Beta (Chaos Master told me how to get
special characters and it doesn't work here)

Doesn't ALT0223 on the numeric keypad, with Num Lock on, work?
ßßß

This alt 0233 --> é looks to me like it's an accented e, as in Jose'
What's it look like to you?


An e with a single dot over it, not the accent mark as in Jose'. I

think it's one of those pronunciation symbols.
--
Best Regards,
Mike

 

[Active8]

On Wed, 31 Dec 2003 19:37:12 +0000, jmw@jmwa.demon.contraspam.yuk
said...

I read in alt.binaries.schematics.electronic that Watson A. Name - Watt
Sun, Dark Remover <alondra101@hotmail.com> wrote (in <MPG.1a5cbb112ab587
88989ae1@news.dslextreme.com&gt about 'Dropping 1V from a Regulated 6V
Wall Wart', on Wed, 31 Dec 2003:

I talked about the weird connector,
someone said it's a Belling Lee connector,

That's a coaxial connector, a bit like a phono plug but with a smaller
centre pin. Is that what you have?

AKA Euro or PAL connector.

I'd forget those descriptions if I were you. Certainly the Belling
connector has very little indeed to do with PAL. It is the subject of an
IEC standard - IEC 60169-2.

It looks (the outer part) exactly like one of those RS push on F

connectors - the male one (male center conductor, female housing)
but the center conductor is hollow and split as if the mating
connector would compress it and cause it to seize the mating
connector's center conductor which in that case would make the CIQ
(connector in question) female and female no thread. I couldn't
quite get a real idea of the size from the photo. Let's check
Pasternack.

The PAL connector in this book is a push on, but the CIQ can't be
this PAL connector. The one I'm looking at is male-female into
female-male with the male housing (which would correspond to the
CIQ) is .370" OD.

I see 75 ohm MCX connectors where the jack corresponding to the CIQ
accepts a plug with a .147" OD housing - seisure and all.

I'd replace the friggin' thing with something I can lay hands on
easily. F connectors are common enough. Push ons I only use for
testing.
--
Best Regards,
Mike

 

[Active8]

On 31 Dec 2003 14:00:52 -0800, Winfield_member@newsguy.com said...

Winfield Hill wrote...

Perhaps my circuit can be combined with Jim's circuit:

: +6.0V, from wall wart
: >--+------+------+
: | | |
: | 220 | Q1 2sa1011
: | | |/E pnp TIP32
: 750 +----| etc
: | | |\
: | |/ |
: +----| Q2 |
: | |\E npn |
: | | |
: | +---+--+----> + output
| | to load
__|___/ 2.7k
/ /\ |
/ \--------o
/ \ |
-------- 2.7k
| TL431 |
| |
- >----o----------o-------> -

I'm still not happy with the poor dropout-voltage capability of
this circuit. It should be able to operate with Vin much closer
to Vout. Aha! Simply adding a diode and resistor lets us reduce
the dropout voltage down to near the saturation voltage of Q1.

: +5.3 to 9V
: >--+-----+------, SIMPLE 5.0V REGULATOR
: | | |
: | 220 | Q1 2sa1011
: | | |/E pnp TIP32
: 470 o----| etc
: | | |\
: | |/ |
: o---| Q2 '----o----> +5.0V
: | |\E npn | output
: | | | to load
: | | 1n4148 |
: | '--o--|<|---o
| | |
__|___/ 1k 2.7k
/ /\ | |
/ \----- | -------o
/ \ | |
-------- | 2.7k
| TL431 | |
| | |
- >----o--------o--------o----> -

Now, did you do this years ago and just walk through the thought
process for the benefit of the group, kinda like the "Now Read This
Article and Burn it." article, pulling a rabbit out of your hat to
the awe of the crowd? or what?

Happy New Year and best of health.

Mike

Of course, an even more simple circuit is possible, using one
of the many low-cost low-dropout three-terminal regulator ICs.

: +5.3 to 9V etc
: >-------, EVEN MORE SIMPLE 5.0V REGULATOR
: __|__
: | |
: | |---+---> +5.0V
: |_____| _|_ output
: | --- to load
: | |
: - >-------o------o---> -

But this circuit isn't as much fun. :&gt

Thanks,
- Win

whill_at_picovolt-dot-com

--
Best Regards,
Mike

 

[Fred Bloggs]

Winfield Hill wrote:

Winfield Hill wrote...

Perhaps my circuit can be combined with Jim's circuit:

: +6.0V, from wall wart
: >--+------+------+
: | | |
: | 220 | Q1 2sa1011
: | | |/E pnp TIP32
: 750 +----| etc
: | | |\
: | |/ |
: +----| Q2 |
: | |\E npn |
: | | |
: | +---+--+----> + output

| | to load
__|___/ 2.7k
/ /\ |
/ \--------o
/ \ |
-------- 2.7k
| TL431 |
| |
- >----o----------o-------> -


I'm still not happy with the poor dropout-voltage capability of
this circuit. It should be able to operate with Vin much closer
to Vout. Aha! Simply adding a diode and resistor lets us reduce
the dropout voltage down to near the saturation voltage of Q1.

: +5.3 to 9V
: >--+-----+------, SIMPLE 5.0V REGULATOR
: | | |
: | 220 | Q1 2sa1011
: | | |/E pnp TIP32
: 470 o----| etc
: | | |\
: | |/ |
: o---| Q2 '----o----> +5.0V
: | |\E npn | output
: | | | to load
: | | 1n4148 |
: | '--o--|<|---o

| | |
__|___/ 1k 2.7k
/ /\ | |
/ \----- | -------o
/ \ | |
-------- | 2.7k
| TL431 | |
| | |
- >----o--------o--------o----> -


Of course, an even more simple circuit is possible, using one
of the many low-cost low-dropout three-terminal regulator ICs.

: +5.3 to 9V etc
: >-------, EVEN MORE SIMPLE 5.0V REGULATOR
: __|__
: | |
: | |---+---> +5.0V
: |_____| _|_ output
: | --- to load
: | |
: - >-------o------o---> -

But this circuit isn't as much fun. :&gt

Thanks,
- Win

whill_at_picovolt-dot-com

If you want a 1V drop (for some reason???) then something like this:


Please view in a fixed-width font such as Courier.


LM185-ADJ
\
+---------|< |---------+
| \ | |
| +------+-------------------------+
| | | |
| / | |
| 470 | |
| / | |
| TIP42 \ | |
Vin----+-------- e c ---+-------+----------------------->Vout
| \ / | | |
| --- | | c
| 10K | 1N4148 | | 10K |/
+----/\/\---+---|>|----+ +--/\/\-----+---|
| | |\
| c e
| \| |
| |---+
| /| |
/ e /
470 | 1.3K
/ | /
\ | \
| | |
--- --- ---

 

[John Woodgate]

I read in sci.electronics.design that Active8 <mTHISREMOVEcolasono@earth
link.net> wrote (in <MPG.1a5d4bc872d800289897e3@news.east.earthlink.net>
) about 'Dropping 1V from a Regulated 6V Wall Wart', on Thu, 1 Jan 2004:

An e with a single dot over it, not the accent mark as in Jose'. I
think it's one of those pronunciation symbols.

The dot instead of a proper accent is a feature of whatever font you are
using. Look at it in Courier, Arial, Times New Roman.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

 

[John Woodgate]

I read in sci.electronics.design that Active8 <mTHISREMOVEcolasono@earth
link.net> wrote (in <MPG.1a5d5365f48735189897e4@news.east.earthlink.net>
) about 'Dropping 1V from a Regulated 6V Wall Wart', on Thu, 1 Jan 2004:

It looks (the outer part) exactly like one of those RS push on F
connectors - the male one (male center conductor, female housing)
but the center conductor is hollow and split as if the mating
connector would compress it and cause it to seize the mating
connector's center conductor which in that case would make the CIQ
(connector in question) female and female no thread. I couldn't
quite get a real idea of the size from the photo. Let's check
Pasternack.

You've described a Belling coax connector, I think. I don't know what
Pasternack is; a connector distributor?

The PAL connector in this book is a push on, but the CIQ can't be
this PAL connector. The one I'm looking at is male-female into
female-male with the male housing (which would correspond to the
CIQ) is .370" OD.

I just don't recognize the term 'PAL connector'.

I see 75 ohm MCX connectors where the jack corresponding to the CIQ
accepts a plug with a .147" OD housing - seisure and all.

I'd replace the friggin' thing with something I can lay hands on
easily. F connectors are common enough. Push ons I only use for
testing.

You should be able to get Belling-type connectors from Farnell/Newark.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

 

[Active8]

On Thu, 1 Jan 2004 07:05:48 +0000, jmw@jmwa.demon.contraspam.yuk
said...

I read in sci.electronics.design that Active8 <mTHISREMOVEcolasono@earth
link.net> wrote (in <MPG.1a5d4bc872d800289897e3@news.east.earthlink.net
) about 'Dropping 1V from a Regulated 6V Wall Wart', on Thu, 1 Jan 2004:

An e with a single dot over it, not the accent mark as in Jose'. I
think it's one of those pronunciation symbols.

The dot instead of a proper accent is a feature of whatever font you are
using. Look at it in Courier, Arial, Times New Roman.

Uh, sorry. It's pretty much the same in all three. The problem is,
at this high screen res it looks like a dot when in fact it's a
small slash.

Hey. If you ever have that prob (I use high res to make room for
large CADs so other apps without zoom are screwed) there a little
toy called Screen Loupe you can get. It's like having a magnifying
glass you can drag around the screen like a sceen color picker or
screen tape measure. Glad I remembered.

--
Best Regards,
Mike

 

[Active8]

On Wed, 31 Dec 2003 14:29:34 -0800, Watson A.Name - "Watt Sun, Dark
Remover" <alondra101@hotmail.com> said...

In article <buCzdbCu7c8$EwFA@jmwa.demon.co.uk>,
jmw@jmwa.demon.contraspam.yuk mentioned...
I read in sci.electronics.design that Active8 <mTHISREMOVEcolasono@earth
link.net> wrote (in <MPG.1a5b77d1462634059897b9@news.west.earthlink.net
) about 'Dropping 1V from a Regulated 6V Wall Wart', on Tue, 30 Dec
2003:
Ok, I incorrectly guessed Beta (Chaos Master told me how to get
special characters and it doesn't work here)

Doesn't ALT0223 on the numeric keypad, with Num Lock on, work?
ßßß

This alt 0233 --> é looks to me like it's an accented e, as in Jose'
What's it look like to you?


------------------------

Hey Watson. You accidentally typed alt 0233 as you said instead of
alt 0223 like John said

Also, measure your connector & see if that MX 75 O [ <== this
little omega looks like a zero. arrrggghhh! No HTML in NNTP
either.]

connector I posted the OD on is close. And if you look back to the
link I posted on these extended ascii codes and other useful (?)
links, you'll see a connector reference link near the top.
-----------------------

--
Best Regards,
Mike

 

[Active8]

On Thu, 1 Jan 2004 07:24:00 +0000, jmw@jmwa.demon.contraspam.yuk
said...

I read in sci.electronics.design that Active8 <mTHISREMOVEcolasono@earth
link.net> wrote (in <MPG.1a5d5365f48735189897e4@news.east.earthlink.net
) about 'Dropping 1V from a Regulated 6V Wall Wart', on Thu, 1 Jan 2004:

It looks (the outer part) exactly like one of those RS push on F
connectors - the male one (male center conductor, female housing)
but the center conductor is hollow and split as if the mating
connector would compress it and cause it to seize the mating
connector's center conductor which in that case would make the CIQ
(connector in question) female and female no thread. I couldn't
quite get a real idea of the size from the photo. Let's check
Pasternack.

You've described a Belling coax connector, I think. I don't know what
Pasternack is; a connector distributor?

Yes. www.pasternack.com It seems like they replace my catalog every
month. They have a UK disty: www.spectech.dial.pipex.com

The PAL connector in this book is a push on, but the CIQ can't be
this PAL connector. The one I'm looking at is male-female into
female-male with the male housing (which would correspond to the
CIQ) is .370" OD.

I just don't recognize the term 'PAL connector'.

I thought PAL was/is (it is) a Europeeeen video standard. But there
is a PAL connector in the cat sure enough and it ain't what
Watson's got.

I see 75 ohm MCX connectors where the jack corresponding to the CIQ
accepts a plug with a .147" OD housing - seisure and all.

----------------------

I'd replace the friggin' thing with something I can lay hands on
easily. F connectors are common enough. Push ons I only use for
testing.
----------------------

You should be able to get Belling-type connectors from Farnell/Newark.

That's a good source for a lot of stuff. In Baltimore there's
Bainsville Electronics which is great, but I've only seen gold-
plated *kits* in the showcase. I'd wager they have it though.
--
Best Regards,
Mike

 

[mike]

Watson A.Name - Watt Sun, Dark Remover wrote:

In article <3FF0D1AC.9070408@juno.com>, spamme0@juno.com mentioned...

Watson A.Name - Watt Sun, Dark Remover wrote:

I needed to drop 1V from a 6VDC 200 mA regulated wall wart, so I tried
a 3 amp rectifier, but it varied by more than .2V over a range of
loads. So I tried this: (view with courier font)

+ From
wall
wart >--+
|
+---+------+
| |
| |
400 \ / 2SC2334 or TIP31
ohm / |/ NPN power TO-220
WW \<-----| Heatsink optional
pot / |\
| E\
| |
| |
+----+-----+
|
|
+------> +
output
to load
- >--------------> -
From wall wart

This has some advantages and disadvantages. It's simple and cheap,
and keeps the output at 5V within a tenth of a volt over a current
range. But it has a minimum current below which it loses regulation
and the output starts to go up to 6V, because the transistor is not
conducting and the current is being supplied thru the ww pot. This
circuit is sometimes used in the bias circuit for the output
transistors in high powered amplifiers. Also Win Hill showed us here
how to use a similar circuit to maintain the voltage steady for a
current regulator circuit used on four AA cell rechargeable batteries.

I'm thinking about putting a 5.1V zener on the output so that if the
voltage climbs above that, it just shunts the excess current. Oh,
yeah, I set the pot to various values to see what the output voltage
was with various loads. The two resistances were 120 ohms for the
upper and 280 ohms for the lower. I suppose the 400 ohms total could
be raised to a higher value, but the transistor needs enough base
current to do its job. There's only 1V available minus the .6V E-B
voltage, so even at 400 ohms, that's not a lot of current.



I've tried to do this on numerous occasions. If you need any amount
of current at all, the big lump of stuff makes it too unweildy, even if you
do bite the bullet and put in a complex circuit that works.

Now, for regulated warts, I crack the case and shunt a resistor inside
the wall wart. You can add a switch if you have multiple applications.
If you need both voltages at once, it's still easier to use two
warts than to have this lump of regulator stuff hanging about.

I'm a little confused by your requirements. If you even considered a
diode, you can't be too concerned about the actual voltage...but you're
concerned about the .2V variability. Sounds like there's something
in there that's important but not disclosed???
mike


Well, I started out in this or another thread with a RF modulator that
requires 4.75 to 5.25VDC, probably because it would be off freq if the
supply V got out of tolerance. I talked about the weird connector,
someone said it's a Belling Lee connector, AKA Euro or PAL connector.
Now I now what it is, and I bot an adapter at Rat Shack for four
bucks. But I wanted something simple that I could solder onto the
pins of the RF modulator, I finally resolved the problem by using a 6V
unregulated wall wart, which is more like 7 or 8V, and a 5.1V zener,
and 39 ohm resistor as a shunt regulator. It works just fine. But I
still wanted a way to drop a single volt, with reasonable regulation,
better than a 1N4003 diode which varies by up to a quarter volt. With
a 1N4003 the voltage could be as high as 5.3 or 5.4V.

My mistake. I read the subject line and the first line of the post
and mistakenly concluded that you wanted to use a regulated wall wart.
My baad.
mike

 

[John Woodgate]

I read in sci.electronics.design that Active8 <mTHISREMOVEcolasono@earth
link.net> wrote (in <MPG.1a5de30f479bf5619897f4@news.east.earthlink.net>
) about 'Dropping 1V from a Regulated 6V Wall Wart', on Thu, 1 Jan 2004:

I thought PAL was/is (it is) a Europeeeen video standard.

Indeed it is; it's the whole phrase 'PAL connector' that I don't
recognize.


--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!

 

[Rich Grise]

Hmm. When I hit alt-0233, I get one of these: !

Cheers!
Rich

"Watson A.Name - Watt Sun, Dark Remover" <alondra101@hotmail.com> wrote in
message news:MPG.1a5ced9a4b431779989ae4@news.dslextreme.com...

In article <buCzdbCu7c8$EwFA@jmwa.demon.co.uk>,
jmw@jmwa.demon.contraspam.yuk mentioned...
I read in sci.electronics.design that Active8 <mTHISREMOVEcolasono@earth
link.net> wrote (in <MPG.1a5b77d1462634059897b9@news.west.earthlink.net
) about 'Dropping 1V from a Regulated 6V Wall Wart', on Tue, 30 Dec
2003:
Ok, I incorrectly guessed Beta (Chaos Master told me how to get
special characters and it doesn't work here)

Doesn't ALT0223 on the numeric keypad, with Num Lock on, work?
ßßß

This alt 0233 --> é looks to me like it's an accented e, as in Jose'
What's it look like to you?

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Active8]

On Fri, 02 Jan 2004 01:02:45 GMT, spamdump@nowhere.net said...

Hmm. When I hit alt-0233, I get one of these: !

Cheers!
Rich

I can say with cetainty that I received an exclaimation point.

Hopeless?

Maybe not. If what I received is what you sent then the same code
is displaying the same character on the screen on both ends. JW and
I seem to have the same settings (odd because he said he used
winders 98), but you either have your locale set differently or
something I haven't though of.

I'm set for English(United State) - Regional and Language settings
in control panel.

Character map isn't working here for omega so I'd better blow it
off.

--
Best Regards,
Mike

 

[Jim Thompson]

On Fri, 02 Jan 2004 02:09:44 GMT, Active8
<mTHISREMOVEcolasono@earthlink.net,invalid> wrote:

On Fri, 02 Jan 2004 01:02:45 GMT, spamdump@nowhere.net said...
Hmm. When I hit alt-0233, I get one of these: !

Cheers!
Rich

I can say with cetainty that I received an exclaimation point.

Hopeless?

Maybe not. If what I received is what you sent then the same code
is displaying the same character on the screen on both ends. JW and
I seem to have the same settings (odd because he said he used
winders 98), but you either have your locale set differently or
something I haven't though of.

I'm set for English(United State) - Regional and Language settings
in control panel.

Character map isn't working here for omega so I'd better blow it
off.

alt-0233 = é with NumLock ON or OFF, Win2K machine

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[James Sweet]

"Active8" <mTHISREMOVEcolasono@earthlink.net,invalid> wrote in message
news:MPG.1a5e9cf2552bf1c4989801@news.east.earthlink.net...

On Fri, 02 Jan 2004 01:02:45 GMT, spamdump@nowhere.net said...
Hmm. When I hit alt-0233, I get one of these: !

Cheers!
Rich

I can say with cetainty that I received an exclaimation point.

Hopeless?

Maybe not. If what I received is what you sent then the same code
is displaying the same character on the screen on both ends. JW and
I seem to have the same settings (odd because he said he used
winders 98), but you either have your locale set differently or
something I haven't though of.

I'm set for English(United State) - Regional and Language settings
in control panel.

Character map isn't working here for omega so I'd better blow it
off.

--
Best Regards,
Mike

Don't type the leading zero unless it's a 2 digit code, ASCII codes are all
3 digit from 000 to 255.

 

[Watson A.Name - "Watt Sun]

In article <d44d2251.0312300857.4c8a4bd0@posting.google.com>,
wadeh@neti.saber.net mentioned...
[snip]

I did this a while back. Replaced the 7806 in the wall wart with a 7805.
Wade

Yeah, but I've got four or five of them and I didn't want to crack
them open and then have to deal with the hassles of a case that's no
longer solidly sealed. And besides, they were only two bucks apiece.
I may bave paid more for their shipping.

Also, I bot four of the 6VDC unregulated wall warts at the same time,
and they have about 7 or 8V output unloaded. I don't think they have
enough voltage to allow a 7805 to work properly, at least not up to
200 mA, because the DC voltage drops down to near 6V at that current.

But 6VDC is a convenient value, used by a lot of equipment that has
four AA cells. So I have them just in case I want to 'electrify' one
of those ol' radios or whatever.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@