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Transformers
Sci.Electronics.Basics is a worldwide Usenet news group that is used to discuss basic electronics questions.
We found 235 threads matching "transformers"
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The most relevant threads are listed first
RF Transformers Lead Colors
2007-03-28 10:59:00
Hello everyone,
I need to use a RF Transformer in a TV circuit, But i can't find it in
my country, So i think to search for it in an old Radio to use it, But
they dont write the frequancy on the Transformers like the do on the
capacitor, And i know that the slider lead color refere to the feq...
Re: Calculating DC Output Current From Unregulated AC Transformer
The Phantom - 2008-07-17 19:41:00
On Fri, 18 Jul 2008 08:31:49 +1000, "Phil Allison"
wrote:
>
> "John Popelish"
>
> > If all transformers were manufactured to a single regulation and
> > temperature rise standard,
>
> ** The vast majority on offer do.
>
> The oft quoted ratio of circa 1.6 applies to stock line...Danfoss autopsy
J.E.B. - 2007-03-31 17:44:00
Recently I dissected a danfoss variable speed a.c. moter drive. I
found what looked like two transformers with only to wires coming from
each. Are these transformers? If so how would this work? anybody
familar with danfoss drives?
...Re: Calculating DC Output Current From Unregulated AC Transformer
Phil Allison - 2008-07-17 18:31:00
"John Popelish"
> If all transformers were manufactured to a single regulation and
> temperature rise standard,
** The vast majority on offer do.
The oft quoted ratio of circa 1.6 applies to stock lines transformers.
..... Phil
...Pulse transformers
Sherlock Holmes - 2010-05-13 21:39:00
As i understand, transformers are meant to pass A/C currents, and
block DC currents. How then is a pulse transformer created that passes
digital pulses through.
...Jacobs Ladders & Stacking Transformers?
2007-03-09 15:28:00
I've build a Jacob's Ladder with an old "Franceformer". The specs
are:
Input; 120 volts - 60 Hz. Output;14,000 volts- 30 Ma.
If I wanted a bigger show and had two identical transformers, could I
stack them for a bigger arc? Would this even be prudent? If not why
not?
If it would be possi...Re: If you had to build a new junk box, what would you buy to put in it?
ZACK` - 2009-02-24 23:05:00
"Wes" wrote in message
news:mJNol.276142$NN4.197081@en-nntp-08.dc1.easynews.com...
> Anyone that has played with electronics for a while ends up with a junk
> box of various
> components. If for some reason you had to start a new one, what are the
> basics you would
> like to hav...What limits the current in an unloaded transformer?
FunFred - 2007-11-09 06:21:00
I got to do some experiments recentley and I realise that my
understanding of transformers has some holes.....
First I got hold of a variac and some resistor loads which I attached
to the transformer.
The transformer got hot, but not too hot, not much new there.
When I wound up the input vo...Re: need a transformer
ehsjr - 2010-01-19 23:35:00
bob haller wrote:
> 120 volt in, 35 volts out 1.2 amps I am having a hard time finding a
> 35 or 36 volts out transformer.
2 transformers, 18V secondaries, 120V primaries.
Primaries in parallel, secondaries in series in phase.
# ----------+
---+-------)||( ...Re: John Larkin's LC oscillator
George Herold - 2010-06-08 22:07:00
On Jun 8, 1:11=A0pm, Winfield Hill wrote:
> George Herold wrote...
>
> > default wrote:
> > > I'd be curious to see values. It isn't "necessary" but I would like
> > > to know what core, type, size and material you used. Did you tweak
> > > the tuning? Running with banks of them ...Re: Driving LEDs with a battery pack
Jon Kirwan - 2009-07-20 12:02:00
On Mon, 20 Jul 2009 22:50:13 +1200, greg
wrote:
> While we're on the subject of transformers, there's
> something that's been bothering me about ordinary
> (non-flyback) transformers.
>
> Consider an unloaded transformer. We apply an AC
> voltage to the primary, and a small magnetising
...SMPS for audio amps
pawihte - 2009-11-12 11:22:00
This is probably a silly question with an obvious answer to those
who know: Why are audio amplifiers seldom powered with
switched-mode power supplies? The common exceptions I know of are
in cases where there are few other options as in car amps or
where an SMPS is for used other sections any...how to id transformers ?
robb - 2007-11-28 23:06:00
i have a couple of mystery transformer pulls {microwave, vcr,
clock radio, etc}
i try to google codes on trans with no proper hits ...
how to id these transformers ? is there a way ? do the numbers
have significance on there own ?
i want to figure/estimate the ratings they might be useful...Microwave oven transformers
terryS - 2009-10-28 16:32:00
Just scrapped another m.wave. Wasn't operating properly, was old, the
display was faulty and what was showing was meaningless. Also
sometimes it had started to microwave for no reason at all when the
door was closed. Was afraid it might become hazardous, e.g. operate
with door faulty or open!
S...Re: What Germanium PNP transistor do I use?
Homer J Simpson - 2007-03-16 23:46:00
wrote in message
news:1174102218.140707.164530@b75g2000hsg.googlegroups.com...
>
> Michael:
> Thanks for your education. But I have an old 4-transistor superhet.
> radio schematic and my kits
> want to build this radio. So I want to find out what Ge transistors I
> need. My radio
...Current Transformers
RogerN - 2009-09-23 20:59:00
In the winter I use oil filled electric radiators in the house to help even
out the heat. The problem is that I always have to remember to shut off the
heater to use other appliances on that circuit, such as the microwave oven.
If I could use a current sensor, and shut off the heater whenever...Questions about Current Transformers:
theCase - 2006-08-27 20:32:00
I've got a tentative plan to try and log power usage in my home, here's
a summary of the plan:
1) Buy two current transformers like these:
http://www.crmagnetics.com/newprod/ProductView.asp?ProdName=CR3110
2) Place one on each "hot" leg of the 240 volts coming into the house,
leaving the gr...transformers
2009-01-04 14:32:00
hey guys !
Does anyone know of an individual or a small company that can wind for
me 1 torodial transformer to test and if it works well , I will need
3 more. ??? Total of 4 . This is for a experiment that I'm in the
middle of.
Thanks
Bruce
...a help please
arjun - 2006-11-15 03:49:00
Hello Friends i have a request:
Can anyone give a good performance
emergency lamp circut for a 11Watt CFL, from 6volt battery, using all
readily available components and
transformers please?
...Re: Driving LEDs with a battery pack
greg - 2009-07-20 06:50:00
While we're on the subject of transformers, there's
something that's been bothering me about ordinary
(non-flyback) transformers.
Consider an unloaded transformer. We apply an AC
voltage to the primary, and a small magnetising
current flows, just enough to induce an emf that
balances out the...Re: Power Supply Rectification and Smoothing
Eeyore - 2007-10-15 12:55:00
BobG wrote:
> maybe just the secondary of a transformer would work?
That would probably be a poor choice actually.
Transformers are designed for AC not DC. The core will probably just saturate
and you'll merely add some DC resistance.
Graham
...more noob questions - transformers
2007-03-28 20:14:00
Ok ... try not to laugh when i ask... tho i only have a few questions
on designing a home made transformer.. And of course i dont want to
burn my house down.. so lets start from there.
I would like to make my own hv transformer and thought i would start
by pulling a apart a regular 12 v...Galvanic disconnection with transformer
Kari Laine - 2010-03-26 13:11:00
Hi,
first. Thank you for all the help I have gotten from here so far.
Now I am trying to figure out how to connect the electricity to my
scopes and the Power supply I am building.
I don't know the right term for a transformer which disconnects galvanic
connection between the electricity n...Re: Radio: Absolute Basics
default - 2009-05-25 19:03:00
On Mon, 25 May 2009 18:53:25 -0400, default
wrote:
> http://home.pacbell.net/lengal/ip/amregen.pdf
> Here's a simple single transistor regen (leave out everything east of
> the 4.7 UF cap and connect earphones from the cap to ground - or add
> the amp and drive a loudspeaker).
Oops - ba...Re: quick emitter follower question
Michael Black - 2006-09-13 19:28:00
Eeyore (rabbitsfriendsandrelations@REMOVETHIS.hotmail.com) writes:
> tempus fugit wrote:
>
> > Hi;
> >
> > I'm thinking about using a simple 1 transistor emitter follower in an audio
> > design (the audio signal will pass thru it). Does the noise figure of the
> > transistor need to b...Voltage required
Roger Dewhurst - 2010-08-03 22:02:00
I have an external hard drive, taken from an older computer, in a Dick
Smith external enclosure. During a move I got all the transformers mixed
up and now I do not know whether this requires 12 volts or 16 volts.
Any ideas?
R
...Re: Transformer
Jamie - 2009-06-13 20:41:00
Roger Dewhurst wrote:
> Some years ago I recall, or at least I think that I do, seeing an
> advertisement for a small cylindrical transformer. Do such things exist
> and if so what are they used for?
>
> RD
Maybe you're referring to toroidal transformers?
http://www.tabtronics.com/...Part numbers
J.E.B. - 2007-04-17 17:37:00
Hey everybody, Anyone care to help A newbie figure out what part
numbers are all about? what I mean here is... I have many parts
( transformers and such) with only a number stamped on them. Is there
Any kind of code or reasoning that corresponds with these numbers?
possibly a referance book tha...Re: Hobby electronics projects-- fire safety?
Ken Moffett - 2007-06-29 17:12:00
"David L. Jones" wrote in
news:1183085635.939528.231170@m37g2000prh.googlegroups.com:
> On Jun 29, 1:37 am, etrave...@hotmail.com wrote:
> > I'm a newbie to electronics, but I've come up with a
> > project to cool a closed electronics cabinet. It uses an
> > ac-dc 12V power (wall war...Transformer drawing 1 amp
2007-03-14 08:17:00
I have a transformer that is drawing about 1 amp when the secondary is
not in use. Is this normal? Its a 15amp 12V CT transformer. The
secondaries read 12 volts from the center like it should(its actually
about 13V). It had what I guess what a thermistor(a rectangular box
that as stuck inside...Re: Transformer winding insulation
default - 2008-12-24 10:26:00
On Sun, 21 Dec 2008 22:27:33 -0500, "sbrehler"
wrote:
> Hello everyone,
>
> Am I correct in that the winding wire in a transformer is coated with a
> varnish that acts as an insulator? I've tried to find an answer to this by
> researching transformer construction, but haven't been able...Re: oscillator needed
Phil Allison - 2007-11-26 23:03:00
> Hi - I need a 10.7 Mhz signal to debug an FM receiver kit I am putting
> together.
** No you dont.
You maybe need an FM modulated signal at 10.7MHz.
> Any suggestions for simple circuitry ?
** Own an FM broadcast radio of any kind?
Just tap into the IF strip and ...inductors and transformer for power electronics book
hossam - 2009-04-12 11:14:00
this book about inductors and transformers and it is use in power
electronics application
the link:
http://rapidshare.com/files/197116503/Inductors_and_Transformers_For_Power_Electronics.rar
best regards
...Re: signal generator circuit
Michael Black - 2007-02-06 00:07:00
(bob@coolgroups.com) writes:
> I'd like to make a circuit that is essentially a signal generator
> producing a 400 kHz signal. I think this can be done with a
> voltage source, resistor, capacitor, and inductor in parallel.
> However, I'm not sure what values are appropriate for the
> re...Re: Low Voltage lighting vs A.C.
Ross Herbert - 2007-06-15 00:21:00
On Wed, 13 Jun 2007 07:44:23 -0400, "David B." wrote:
> I want to do some landscape lighting and wondering if using a 12volt
> system(20 watt bulb) is more efficient than normal 120 volt (20 watt
Bulb).
>
It is much safer to use 12V for domestic outdoor lighting. Depending
on the n...wall wart basic question
LB - 2007-02-06 20:01:00
I have a electronic device that uses an OEM ($$$) wall wart rated at
5VDC and 220mA. In my collection of transformers I found one rated at
5VDC with the same plug/ polarity except it's rated at 500mA. Would it
be okay to use or should mA ratings match more closely?? Thanks.
...Re: An "active" device
Bob Myers - 2007-08-02 21:21:00
"JeffM" wrote in message
news:1186102598.910040.275650@z24g2000prh.googlegroups.com...
> Trying to define it so that a relay is excluded[1]
> but semiconductors used in digital mode aren't is kinda tough.
> The definition offered by "Nobody"
> http://www.google.com/search?q=define:act...Re: Calculating DC Output Current From Unregulated AC Transformer
Paul E. Schoen - 2008-07-19 03:29:00
"Phil Allison" wrote in message
news:6eb1v3F67vuuU1@mid.individual.net...
>
> "Paul E. Schoen"
> "Phil Allison"
> > >
> > > > Ordinary waveform distortion (and normal transformer saturation) will
> > > > usually cause a flattening of the peaks
> > >
> > >
> > > ** Where in ...Re: Voltage conversion
Eeyore - 2009-05-01 08:06:00
Anon Email wrote:
> Hi People,
>
> I'm an Aussie going to Korea to live for a year or two. I'm bringing
> some appliances with me. The Australian rating is 240V/ 50 Hz. Korea
> is 220V/ 60 Hz. Will I need a transformer? I read somewhere that
> transformers for home use are generall...Re: Ferrite Transformer ?
Anthony Fremont - 2007-03-21 15:21:00
mowhoong@hotmail.com wrote:
> Some hobby project uses E or Round type of ferrite transformer which
> are found in the HV driver
> circuit. As this is uncommon or a standard type item, i like to know
> how to self made one,
It would be helpful if you better described the particular appli...