W
Winston
Guest
John Larkin wrote:
(...)
--Winston
(...)
You are *so* close to the real answer!
--Winston
J
John Larkin
Guest
On Sat, 30 Jul 2011 11:46:10 -0700, Winston <Winston@BigBrother.net>
wrote:
John
wrote:
What's the question?
John
W
Winston
Guest
John Larkin wrote:
"I have a half-wave rectified signal (half of 120 Vac passed through a
diode), and I would like to convert it to a ~60 Vrms wave that is
clean enough to run a small AC motor.
Is this even possible?"
--Winston
Per eromlignod@aol.com, the OP:
"I have a half-wave rectified signal (half of 120 Vac passed through a
diode), and I would like to convert it to a ~60 Vrms wave that is
clean enough to run a small AC motor.
Is this even possible?"
--Winston
J
John Fields
Guest
On Fri, 29 Jul 2011 22:14:40 -0700, Winston <Winston@BigBrother.net>
wrote:
Very nice!
--
JF
wrote:
---
Very nice!
--
JF
W
Winston@bigbrother.net
Guest
John Fields wrote:
--Winston
Thanks, John!On Fri, 29 Jul 2011 22:14:40 -0700, Winston<Winston@BigBrother.net
wrote:
Winston wrote:
Winston wrote:
Winston wrote:
eromlignod wrote:
Gentlemen:
I'm an ME, not a EE so be gentle with me.
I have a half-wave rectified signal (half of 120 Vac passed through a
diode), and I would like to convert it to a ~60 Vrms wave that is
clean enough to run a small AC motor.
Is this even possible?
Notice how the current in the primary becomes
'almost symmetrical' within about half a second
of startup:
Rather:
Version 4
SHEET 1 880 680
WIRE -64 16 -128 16
WIRE 224 16 0 16
WIRE 448 16 224 16
WIRE -128 80 -128 16
WIRE 656 80 560 80
WIRE 448 96 448 16
WIRE 560 96 560 80
WIRE 224 112 224 16
WIRE 656 112 656 80
WIRE 560 224 560 176
WIRE 656 224 656 192
WIRE 656 224 560 224
WIRE 448 240 448 176
WIRE 560 240 560 224
WIRE -128 256 -128 160
WIRE 224 256 224 176
FLAG 224 256 0
FLAG -128 256 0
FLAG 448 240 0
FLAG 560 240 0
SYMBOL cap 208 112 R0
SYMATTR InstName C2
SYMATTR Value 7.036201ľF
SYMBOL ind2 432 80 R0
SYMATTR InstName L1
SYMATTR Value 1
SYMATTR SpiceLine Rser=.01
SYMATTR Type ind
SYMBOL voltage -128 64 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value SINE(0 170 60 0 0 0 100000)
SYMBOL diode -64 32 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName D1
SYMATTR Value MUR460
SYMBOL ind2 576 192 R180
WINDOW 0 36 80 Left 0
WINDOW 3 36 40 Left 0
SYMATTR InstName L2
SYMATTR Value .2525
SYMATTR SpiceLine Rser=.01
SYMATTR Type ind
SYMBOL res 640 96 R0
SYMATTR InstName R1
SYMATTR Value 600
TEXT -160 472 Left 0 !.tran 0 10 0
TEXT 464 56 Left 0 !K L1 L2 0.99
---
Very nice!
--Winston
J
John Fields
Guest
On Sat, 30 Jul 2011 11:28:35 -0700, John Larkin
<jjSNIPlarkin@highTHISlandtechnology.com> wrote:
That's not very considerate, John.
Instead of that .gif bullshit, why didn't you just post the circuit
list so that we could run it without having to copy it manually?
--
JF
<jjSNIPlarkin@highTHISlandtechnology.com> wrote:
---
That's not very considerate, John.
Instead of that .gif bullshit, why didn't you just post the circuit
list so that we could run it without having to copy it manually?
--
JF
J
John Larkin
Guest
On Sun, 31 Jul 2011 15:13:49 -0500, John Fields
<jfields@austininstruments.com> wrote:
If you were interested in what's going on here - which you probably
aren't - you could enter it yourself in 30 seconds.
I post an interesting circuit, and you have nothing to say about the
electronics content, you just snivel about the way I posted it.
You have become a chronic whiner. Nobody likes a whiner.
John
<jfields@austininstruments.com> wrote:
Bullwhat?
If you were interested in what's going on here - which you probably
aren't - you could enter it yourself in 30 seconds.
I post an interesting circuit, and you have nothing to say about the
electronics content, you just snivel about the way I posted it.
You have become a chronic whiner. Nobody likes a whiner.
John
R
Rich Grise
Guest
eromlignod wrote:
many variables. Like, what's the impedance and PF of the load?
Good Luck!
Rich
the pulsating DC; I'm not going to speculate about the cap value - too
many variables. Like, what's the impedance and PF of the load?
Good Luck!
Rich
J
John Fields
Guest
On Sun, 31 Jul 2011 13:47:36 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
Oh, sorry. Bullarkin.
---
You give me too much credit.
If I wasn't interested I would have just passed it by but, since I
was, I was disappointed when there was an unnecessary price, however
slight, exacted in order to pursue that interest.
A Larkin tax, if you will...
But that's really beside the point, since what I asked you was why you
didn't just post the circuit list and make it easy, for anyone who was
interested, to run the circuit without having to copy it by hand.
I've received no answer, so I'll ask you again:
Why didn't you just post the circuit list?
---
Asking why you chose to post it in a way that makes it inconvenient
for anyone who's interested in discussing the circuit is hardly
sniveling; it's more like trying to ferret out why you're such a cunt.
---
You like to call criticism "whining", in order to put it in a negative
light while trying to maintain your position as an authoritarian, and
you like to pretend that you have the insight to determine who likes
what.
--
JF
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
---
Oh, sorry. Bullarkin.
---
---
You give me too much credit.
If I wasn't interested I would have just passed it by but, since I
was, I was disappointed when there was an unnecessary price, however
slight, exacted in order to pursue that interest.
A Larkin tax, if you will...
But that's really beside the point, since what I asked you was why you
didn't just post the circuit list and make it easy, for anyone who was
interested, to run the circuit without having to copy it by hand.
I've received no answer, so I'll ask you again:
Why didn't you just post the circuit list?
---
---
Asking why you chose to post it in a way that makes it inconvenient
for anyone who's interested in discussing the circuit is hardly
sniveling; it's more like trying to ferret out why you're such a cunt.
---
---
You like to call criticism "whining", in order to put it in a negative
light while trying to maintain your position as an authoritarian, and
you like to pretend that you have the insight to determine who likes
what.
--
JF
J
John Larkin
Guest
On Sun, 31 Jul 2011 17:23:19 -0500, John Fields
<jfields@austininstruments.com> wrote:
If you're not interested enough to enter it, then don't enter it.
because not everybody runs LT Spice. I wanted to present a concept,
namely parametric sub-harmonic oscillation, not a circuit to be aped.
The ftp image was actually posted some months ago, with reference to
another thread.
women and then using that degradation as an insult.
What a sick old queen you are. You keep projecting onto me all you own
misogyny and hangups and perversions. They are not mine, they are
yours; man up and face it.
John
<jfields@austininstruments.com> wrote:
OK, 30 minutes.
So go away and don't pay. It's not mandatory, so it's not a tax.
If you're not interested enough to enter it, then don't enter it.
Because I wanted to include the schematic and the waveforms, and
because not everybody runs LT Spice. I wanted to present a concept,
namely parametric sub-harmonic oscillation, not a circuit to be aped.
The ftp image was actually posted some months ago, with reference to
another thread.
You recently criticized me - entirely incorrectly - for degrading
women and then using that degradation as an insult.
What a sick old queen you are. You keep projecting onto me all you own
misogyny and hangups and perversions. They are not mine, they are
yours; man up and face it.
John
J
John Fields
Guest
On Sun, 31 Jul 2011 18:51:21 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
You're right about that, but I suspect whoever doesn't run LTspice is
living under a bridge somewhere, sans computer, and so won't have
access to the schematic and waveforms anyway.
---
Strange, then, that you didn't post the FFT as well.
---
Well, from your past performances, one would hardly expect you to
accept criticism objectively so, without the proof to refute my past
criticism, your statement that my criticism was incorrect is entirely
hollow.
---
I'm not a projector, John, I'm just a mirror.
But "Man" up???
Now _that's_ funny, coming from you!
--
JF
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
---
You're right about that, but I suspect whoever doesn't run LTspice is
living under a bridge somewhere, sans computer, and so won't have
access to the schematic and waveforms anyway.
---
---
Strange, then, that you didn't post the FFT as well.
---
---
Well, from your past performances, one would hardly expect you to
accept criticism objectively so, without the proof to refute my past
criticism, your statement that my criticism was incorrect is entirely
hollow.
---
---
I'm not a projector, John, I'm just a mirror.
But "Man" up???
Now _that's_ funny, coming from you!
--
JF
J
Jasen Betts
Guest
On 2011-07-30, Winston <Winston@BigBrother.net> wrote:
without the diode present. (only 10% more) and the settling time
is reduced. so a tranformer wound for 10% extra voltage should be
fine. probably easiest to just use a 230V transformer
I notice that the capacitor despite being specified to 6 digits can be
varied +/- 50% with little effect on the transformer
with a capacitor of that size something should be done to protect the
rectifier from power-on transients. (set the phase to -180 degrees (on
the AC supply) and turn on "skip initial operating point" (under "edit
run command"))
--
ââ 100% natural
interesting, the transformer sees about the same flux it would have
without the diode present. (only 10% more) and the settling time
is reduced. so a tranformer wound for 10% extra voltage should be
fine. probably easiest to just use a 230V transformer
I notice that the capacitor despite being specified to 6 digits can be
varied +/- 50% with little effect on the transformer
with a capacitor of that size something should be done to protect the
rectifier from power-on transients. (set the phase to -180 degrees (on
the AC supply) and turn on "skip initial operating point" (under "edit
run command"))
--
ââ 100% natural
P
Phil Allison
Guest
"Winston"
** A power transformer primary is NOT an inductor !!!
Any current flow in the primary winding that is not the result of load
current in the secondary must not exceed I mag or gross core saturation will
occur.
( I mag ranges from about 0.5% to 10% of rated primary current for
commercial transformers.)
Iron cored * inductors * have deliberate air gaps in the core (while
transformers have none) which sets up a usable current level that will avoid
core saturation. Such gaps also dramatically reduce the inductance figure
compared to the un-gapped case.
As I have already posted, the OP merely needs a suitable series cap ( poly
film) to drop 60 volts off the AC supply to his motor.
Here's a tip, never suggest anyone feed a mains transformer primary via a
diode - less you want to start a fire.
..... Phil
** A power transformer primary is NOT an inductor !!!
Any current flow in the primary winding that is not the result of load
current in the secondary must not exceed I mag or gross core saturation will
occur.
( I mag ranges from about 0.5% to 10% of rated primary current for
commercial transformers.)
Iron cored * inductors * have deliberate air gaps in the core (while
transformers have none) which sets up a usable current level that will avoid
core saturation. Such gaps also dramatically reduce the inductance figure
compared to the un-gapped case.
As I have already posted, the OP merely needs a suitable series cap ( poly
film) to drop 60 volts off the AC supply to his motor.
Here's a tip, never suggest anyone feed a mains transformer primary via a
diode - less you want to start a fire.
..... Phil
W
Winston
Guest
Phil Allison wrote:
Ignition coils (autotransformers, yes?) operate with large amounts of
D.C. present through the primary.
http://www.instructables.com/files/deriv/FC6/CXUK/F6B7Q84T/FC6CXUKF6B7Q84T.MEDIUM.jpg
If the supply were alternating current, that'd work if efficiency and
D.C. offset across the motor weren't considerations.
The supply is pulsed D.C. though.
If we are free to change the request, I hereby redefine the OP's
requirement:
WAS:"I have a half-wave rectified signal (half of 120 Vac passed through a
diode), and I would like to convert it to a ~60 Vrms wave that is
clean enough to run a small AC motor."
IS:"I have a 60 Vrms sinewave, and I would like to convert it to a ~60 Vrms
sinewave that is clean enough to run a small AC motor."
The task is now somewhat simpler, yes?
If you run the simulation, you'll see that the worst-case D.C. component
through the unloaded primary is ca. 9 milliamps.
Any EI core transformer over 250 W should have no problem.
--Winston
Most don't. Welding transformers can have a large adjustable air gap.
Ignition coils (autotransformers, yes?) operate with large amounts of
D.C. present through the primary.
http://www.instructables.com/files/deriv/FC6/CXUK/F6B7Q84T/FC6CXUKF6B7Q84T.MEDIUM.jpg
Could you post your LTSpice .asc of that for me please?
If the supply were alternating current, that'd work if efficiency and
D.C. offset across the motor weren't considerations.
The supply is pulsed D.C. though.
If we are free to change the request, I hereby redefine the OP's
requirement:
WAS:"I have a half-wave rectified signal (half of 120 Vac passed through a
diode), and I would like to convert it to a ~60 Vrms wave that is
clean enough to run a small AC motor."
IS:"I have a 60 Vrms sinewave, and I would like to convert it to a ~60 Vrms
sinewave that is clean enough to run a small AC motor."
The task is now somewhat simpler, yes?
Normally a good idea.
If you run the simulation, you'll see that the worst-case D.C. component
through the unloaded primary is ca. 9 milliamps.
Any EI core transformer over 250 W should have no problem.
--Winston
J
John Larkin
Guest
On Mon, 01 Aug 2011 02:16:21 -0500, John Fields
<jfields@austininstruments.com> wrote:
electronics.
John
<jfields@austininstruments.com> wrote:
What a massive heap of lame words, all to avoid discussing
electronics.
John
P
Phil Allison
Guest
"Winston"
All cored inductors have deliberate air gaps - whether ferrite, iron or
composite materials that include a myriad of tiny non-magnetic gaps.
** Don't be fucking absurd.
** The AC supply is obviously available - you stupid, fucking wanker.
** OK - you go get a mains transformer and TRY it.
Your simulation is BOLLOCKS !!
...... Phil
** You have no idea what you are talking about !!!
All cored inductors have deliberate air gaps - whether ferrite, iron or
composite materials that include a myriad of tiny non-magnetic gaps.
** Don't be fucking absurd.
** The AC supply is obviously available - you stupid, fucking wanker.
** You are a complete, fucking idiot.
** OK - you go get a mains transformer and TRY it.
Your simulation is BOLLOCKS !!
...... Phil
W
Winston
Guest
Phil Allison wrote:
deliberate air gaps in the magnetic circuit. Some do. Not all.
Pot core transformers and simple welding transformers
can have deliberate air gaps, for example.
(...)
asking for clarification? Placing a cap in series with the
cathode of that rectifier will raise the average D.C. into the
OP's motor far higher than would the resonant transformer
approach. I don't yet understand how you met the design goals
and constraints by doing that. I'm here in sci.electronics.basics
to learn. If you modeled your approach in LTSpice, I would
then understand what you are really saying as opposed to what
I *think* you are saying.
"I have a half-wave rectified signal (half of 120 Vac passed
through a diode...)"
Please compare that to what he didn't say:
"I have 120 Vac..."
These statements are contradictory, yes?
He may have made a mistake, so I would be pleased to hear
him say that the AC *is* available. I agree that would
be much simpler and a completely different problem.
in the primary is likely to cause sufficient magnetic
saturation at the positive current peaks to cause the
transformer to overheat to the point of ignition?
Did I get that right?
--Winston
Um, Phil? I was agreeing with you; most transformers have no
deliberate air gaps in the magnetic circuit. Some do. Not all.
Pot core transformers and simple welding transformers
can have deliberate air gaps, for example.
(...)
What is ridiculously unreasonable, unsound, or incongruous about
asking for clarification? Placing a cap in series with the
cathode of that rectifier will raise the average D.C. into the
OP's motor far higher than would the resonant transformer
approach. I don't yet understand how you met the design goals
and constraints by doing that. I'm here in sci.electronics.basics
to learn. If you modeled your approach in LTSpice, I would
then understand what you are really saying as opposed to what
I *think* you are saying.
The OP clearly said that it isn't. I quote:
"I have a half-wave rectified signal (half of 120 Vac passed
through a diode...)"
Please compare that to what he didn't say:
"I have 120 Vac..."
These statements are contradictory, yes?
He may have made a mistake, so I would be pleased to hear
him say that the AC *is* available. I agree that would
be much simpler and a completely different problem.
I'm not done yet; I am incomplete.
You feel that raising the average D.C. current above zero
in the primary is likely to cause sufficient magnetic
saturation at the positive current peaks to cause the
transformer to overheat to the point of ignition?
Did I get that right?
--Winston
P
Phil Allison
Guest
"Winston"
** Read what I wrote - you fucking tenth wit.
** That says he has the 120 volt AC supply available.
My god, you are an autistic moron.
** Finally.
Now, piss off.
..... Phil
** None do.
** Not true of either.
** Read what I wrote - you fucking tenth wit.
** That says he has the 120 volt AC supply available.
My god, you are an autistic moron.
** You are an utter ass.Here's a tip, never suggest anyone feed a mains transformer primary via
a
diode - less you want to start a fire.
Normally a good idea.
** You are a complete, fucking idiot.
I'm not done yet; I am incomplete.
** Finally.
Now, piss off.
..... Phil
M
m II
Guest
eromlignod wrote:
Have you considered a brushed motor? A big capacitor and a half wave
source should drive it easy. It may have to be a 24 volt motor, though.
The brushed motor will run on either AC or DC.
mike
Have you considered a brushed motor? A big capacitor and a half wave
source should drive it easy. It may have to be a 24 volt motor, though.
The brushed motor will run on either AC or DC.
mike
W
Winston
Guest
Phil Allison wrote:
Note the magnetic circuit coupling the primary of this welding
transformer to it's secondary. Normally the flux is free to
induce current into the secondary. If the weldor requires less
current in the secondary, he may insert a magnetic shunt in the
gap between the two windings to divert the magnetic field away
from the secondary.
Under Step 7: "However for flyback transformers and chokes, an air
gap is necessary."
Coilcraft thinks so, so do I.
AC motor, then return to neutral.
The current does not ever fall below zero and go negative.
The voltage does go above and below ground but does not
resemble any sinewave I've ever seen.
I just don't see this driving a motor effectively even if
one could locate a source of ~250 VAC poly caps to assemble
the thousands of microfarads needed.
Pulsed D.C. is not alternating current.
He may indeed have the AC supply available but the
engineering constraint is that he cannot provide it.
--Winston
http://info.ee.surrey.ac.uk/Workshop/advice/coils/leak/weld/index.html
Note the magnetic circuit coupling the primary of this welding
transformer to it's secondary. Normally the flux is free to
induce current into the secondary. If the weldor requires less
current in the secondary, he may insert a magnetic shunt in the
gap between the two windings to divert the magnetic field away
from the secondary.
http://www.coilcraft.com/pdfs/doc627_Power_transformer_design.pdf
Under Step 7: "However for flyback transformers and chokes, an air
gap is necessary."
Coilcraft thinks so, so do I.
Pulsed 170 V D.C. in series with a poly film cap and the OP's 60 V
AC motor, then return to neutral.
The current does not ever fall below zero and go negative.
The voltage does go above and below ground but does not
resemble any sinewave I've ever seen.
I just don't see this driving a motor effectively even if
one could locate a source of ~250 VAC poly caps to assemble
the thousands of microfarads needed.
Nup. He has pulsed D.C.
Pulsed D.C. is not alternating current.
He may indeed have the AC supply available but the
engineering constraint is that he cannot provide it.
You *are* beautiful when you are angry.My god, you are an autistic moron.
Here's a tip, never suggest anyone feed a mains transformer primary via
a
diode - less you want to start a fire.
Normally a good idea.
** You are a complete, fucking idiot.
I'm not done yet; I am incomplete.
** You are an utter ass.
** OK - you go get a mains transformer and TRY it.
Your simulation is BOLLOCKS !!
You feel that raising the average D.C. current above zero
in the primary is likely to cause sufficient magnetic
saturation at the positive current peaks to cause the
transformer to overheat to the point of ignition?
Did I get that right?
** Finally.
Now, piss off.
--Winston