Sign in
Search Sci.Electronics.Design
design by Keywords
8051 | Amplifier | AVR | CMOS | Converter | DAC | Diode | FPGA | GPS | I2C | IDE | Laser | LCD | MOSFET | Op-amp | Oscillator | Oscilloscope | PID | PLL | PSU | PWM | RFID | RS232 | RS485 | SMPS | Spice | Transformer | Transistor | TTL | USB | VCO
Ads
See Also
Transformer
Sci.Electronics.Design is a worldwide Usenet news group that is used to discuss various aspects of Electronic Circuit Design.
We found 972 threads matching "transformer"
You are looking at page 1 of 25.
The most relevant threads are listed first
HF step up transformer
Jamie Morken - 2008-05-19 11:24:00
Hi,
For a step up transformer with an input voltage of 60VDC to 125VDC, and
a fixed output voltage of 420VDC, at 350watts, what is the most
efficient transformer type to use? I would like to use a flyback but I
don't know if I can get to 92%+ efficiency with this.
cheers,
Jamie
...
power supply circuit
F Murtz - 2008-06-09 08:42:00
I would like to make an adjustable power supply using a transformer with
a 24v 5a single wound secondary I would like the voltage to be
adjustable from lowest to highest possible given transformer I would
like to have regulated current
There is another possibility I also have a larger trans...Any technical reason not to use isolation transformer to make DC?
Mike Silva - 2008-04-25 10:10:00
If I want a source of 150-160VDC is there any technical reason why I
shouldn't use an isolation transformer to feed a rectifier & filter?
As opposed to a purpose-designed 120VAC secondary "power transformer"?
Mike
...Re: Transformer insulateing tape?
Jan Panteltje - 2010-06-21 08:22:00
On a sunny day (Sun, 20 Jun 2010 16:46:04 -0700) it happened Perenis
wrote in
:
> It is NOT an AC fed transformer, it is an ACfed front end on this
> supply. The transformer is DOWNSTREAM, in the DC section.
>
> It most certainly CAN be fully isolated long before it gets to the
> ...FCC phone line and transformer
2009-02-08 11:29:00
I have a few modems laying around and noticed, (especially on the
lower cost ones), that there isn't even a transformer on the PCB for
interfacing to telphone line.
All of them are using DAA chips but I would assume that a transformer
would almost be mandatory in getting part 68? approval.
...using step-down transformer as step-up
2009-02-10 22:25:00
At first blush, it seems like you should be able to use a power
transformer as either step-down or step-up, simply by feeding the
input into either the primary or secondary. However, is this really
the case? For example, consider one of those pole transformers that
normally step down, say, 12k...calculating saturation current of transformer
2008-08-27 13:21:00
I have designed a 1:1 transformer that will be used in a low voltage
DC:DC converter. I have tested the current at which the transformer
saturates by decreasing the frequency of the primary voltage while
keeping the secondary open loop.
I would like to calculate the theoretical value of the cu...Re: calculating saturation current of transformer
Phil Allison - 2008-08-28 07:54:00
> I have designed a 1:1 transformer that will be used in a low voltage
> > > DC:DC converter. I have tested the current at which the transformer
> > > saturates by decreasing the frequency of the primary voltage while
> > > keeping the secondary open loop.
> >
> > ** How is that fi...Re: How do you call that (winding)
Tim Wescott - 2009-07-21 13:07:00
On Tue, 21 Jul 2009 18:15:11 +0200, Fred Bartoli wrote:
> How do you call the winding method where both primary and secondary
> windings have the same turn count and are wound at the same time with 2
> parallel wires.
>
> In French it's "two wires in hand" but I can't find that, so...
...transformer ET specs
Jamie Morken - 2008-02-14 00:29:00
Hi,
For this gate drive transformer:
http://www.coilcraft.com/da2099.cfm
It has a Volt-time spec of 221 V-us)
So the primary will saturate in 1us
at 221 volts, or 20us at 11 volts I think.
This transformer is specced to work for gate
driving from 20kHz to 250kHz, and it has a 1:1
t...R-core mains transformer problem
N_Cook - 2009-12-21 10:26:00
300W transformer that over 4 years of use, the secondary voltages are 10
percent lower than originally, at least. Measuring without full rated
loading, so worse than that under load presumably.
If the transformer was severely jarred, via its mounting bolts, could that
open up the core closure an...transformer tap switches (relay or fets)
Jamie Morken - 2008-01-25 11:37:00
Hi,
I am using a transformer with tap switches to accomodate a wide input
voltage range, initially I was going to use fets for the tap switches
(two in series for each tap switch with sources and gates connected),
but since the tap switch frequency is very low (lower than once per
minutes av...Re: Transformer insulateing tape?
Perenis - 2010-06-21 13:20:00
On Mon, 21 Jun 2010 12:22:47 GMT, Jan Panteltje
wrote:
> On a sunny day (Sun, 20 Jun 2010 16:46:04 -0700) it happened Perenis
> wrote in
> :
>
> > It is NOT an AC fed transformer, it is an ACfed front end on this
> > supply. The transformer is DOWNSTREAM, in the DC section.
> > ...Optoisolated TRIAC Trigger
eeboy - 2009-12-12 08:48:00
I am using a MOC3023 optoisolated triac trigger
(http://www.fairchildsemi.com/ds/MO/MOC3010M.pdf) to control the HV pulse
to a xenon flash tube directly. Essentially one end of the TRIAC ties to
the trigger transformer and the other to ground. A .047uF cap feeds the
primary of the trigger transforme...Smps Ferrites, Frequency and Loss
D from BC - 2008-03-04 14:58:00
Ugh...I have to change a non-isolated 700khz Cuk converter into an
isolated version.
Safety reasons.
Currently, the power inductors feel like 30C. Nice @~100W transfer.
I suspect, popping in an isolation transformer running at 700khz will
create a humongous drop in efficiency.
Transforme...Transformer Leakage Inductance
Artist - 2009-04-14 21:25:00
I am concerned about the output impedance of a transformer with a center
tapped primary that will be driven in a class A push pull topology.
Will the part of the secondary that couples to the half of the primary
that is not being driven, and is open circuit, appear in the output
impedance a...calculating transformer saturation
Jamie Morken - 2007-12-29 17:07:00
Hi,
I am trying to calculate the max number of turns that I can
use in a transformer at a given current using the formula from this
page:
http://info.ee.surrey.ac.uk/Workshop/advice/coils/#turn
N = Bsat*le / (μ*I)
where:
N = turns
Bsat = saturation flux density (Tesla)
le = effecti...PS for PWM-controlled motor
pimpom - 2010-01-31 03:13:00
I don't know if this should be in seb rather than in sed, but
here goes. I have this brushed motor from an old machinery with
an integral reduction gear. The label has faded completely so
that it's impossible to read the nameplate ratings. It was
powered from a transformer that outputs 26.5V...Re: FUCK OFF- you STUPID DAMN TROLL
Jon Kirwan - 2009-05-17 03:04:00
On Sun, 17 May 2009 16:52:41 +1000, "Phil Allison"
wrote:
> "Jon Kirwan" > > > >
> > > > > > > > > > It looks about like your basic radio shack 12.6V @ 1A transformer,
> > > > > > >
> > > > > > > > I've identified what must be the 120VAC pair -- 5
> > > > > > > > ohms (using Tektr...Re: Transformer issue
John Fields - 2010-02-23 06:15:00
On Mon, 22 Feb 2010 22:34:32 -0600, krw wrote:
> Yeah, we're all going to lose sleep over the energy lost because of an
> audio transformer.
>
>
>
---
So...
You're part of the problem.
JF
...Hbridge transformer driving series cap
Jamie Morken - 2008-06-13 01:20:00
Hi,
I am driving a transformer with an Hbridge, like this circuit:
http://www.hills2.u-net.com/electron/fullbrdg.gif
I am wondering about using a series cap on the transformers primary,
if it is necessary or not. I am using an FPGA to control the fets
gates, so should be able to keep the...Neon Transformer Question
Bob1001 - 2009-08-20 23:51:00
Hi All,
I recently came across a very large sum of neon transformers. The
input is 277v for the primary, the secondary is kicking out 30
miliamps at 7500v. I have some pictures of the transformer on my
website: www.doranaerospace.com/Images/neon
does anybody have any idea of what they are w...Best way to shield surface mount transformers
Nemo - 2010-07-15 17:12:00
I designed an isolated switchmode supply using an off-the-shelf surface
mount transformer which is wound on an E shaped core with pins down 2
opposing sides. It works OK, but you can reduce noise by adding a
grounded shield - for my prototype I made this from copper tape,
wrapping around the...Ethernet interconnection between two embedded PC's inside one box
Bert - 2008-02-29 09:35:00
Hi,
I have a question about interconnecting two embedded PC's by Ethernet.
Our situation:
- PC A has the LXT9785 Ethernet PHY of Intel, internal termination,
with 1:1 transformer and 1nF/2kV capacitor at the TX and RX center
taps at the secundairy side.
- PC B has the 82562ET Ethernet PH...Otptofets
Jon Slaughter - 2010-02-17 18:46:00
Are there devices that are fet based and have optical isolation? e.g., maybe
something that uses a transformer to isolate the gate? I remember seeing, I
think from TI, some very small transformer isolation IC's and I imagine one
could combine this with a fet to get some pretty responsive isola...A simple cheap current transformer with good bandwidth...
Jan Panteltje - 2009-06-29 09:40:00
A simple cheap current transformer with good bandwidth...
Been using this one now for many years, it measures the mains current.
ftp://panteltje.com/pub/play_back_head_current_sensor_img_1153.jpg
The sensor, or current transformer if you like,
is a old audio playback head from a walkman IIRC.
...Re: Simple 60 Khz Transmitter Design?
2008-02-03 15:56:00
Thanks all for the input. My understanding is what I am doing is legal
in Australia, as long as I don't exceed the maximum EIRP for LIPDs in
this frequency range. With my current plans I don't think that is
possible. I want to use simple components I have available to me and I
am familiar with. ...Re: Transformer issue
krw - 2010-02-22 23:34:00
On Tue, 23 Feb 2010 03:51:52 +0000 (UTC), don@manx.misty.com (Don
Klipstein) wrote:
> In , krw said (edited for space):
> > On 22 Feb '10 16:01:08 -0600, J Fields wrote:
> >
> > > On Mon, 22 Feb 2010 13:01:52 -0600, krw wrote:
> > >
> > > > On 21 Feb 2010 13:13:24 -0800, R. Baer ...Anyone know the specs for this transformer - U53PP206 53X0562-001 F EIA-549-9527
Default User - 2009-01-12 14:26:00
Hi,
The EIA-549 shows me something about midwest coil and transformer, and I
have to assume the "9527" means something I just can't find a table to show
what. Any idea how many watts it can handle?
Thanks,
Alan
...Rewinding a shorted SMPS transformer
Jim Flanagan - 2010-02-17 17:24:00
I have a defective SMPS transformer which I cannot replace and
am contemplating rewinding the primary which has shorted
internally. I've rewound 60Hz power transformers in the past with
no problems. What are some pitfalls that I might run into when
attempting this.
Any help is appreciated...Transformer design software
markp - 2010-07-19 09:00:00
Hi All,
I'm looking for simple to drive, and cheap, transformer design software that
can cope with saturable cores and various types of construction (e.g. 3
legged version with windings on both outer limbs and the inner limb, such is
used in saturable core reactors).
Basically I want to ...Transformers for switching power supplies - sources for stock parts.
John Nagle - 2009-04-20 23:54:00
Where do you find stock transformers for switching power supply design?
Apparently, for most commercial work, the transformer is at least semi-custom.
And no, I don't want to wind my own. I can model what I want in LTSpice,
but the transformer I've defined is not a standard part.
Digi...Positive And Negative Voltages from one transformer
rich - 2010-08-31 15:14:00
I have a circuit requiring two equal voltages, one positive and one
negative. Is there a proven way to obtain these voltages from one
transformer?
Perhaps two bridge rectifiers sharing the secondary center tap and a
common ground?
Thanks
Rich
...Re: AC Voltage Reference
Rich Grise - 2008-12-23 13:19:00
On Mon, 22 Dec 2008 13:53:12 -0800, Mio wrote:
>
> Use a constant voltage transformer, and hook it up to a 240/224
> transformer. CVTs seem very expensive, though. So I don't really like
> this.
Of course! Googles NEVER like the right answer - I think that's why they
resort to googlegr...Mains transformer goodness
N_Cook - 2009-03-20 03:53:00
Something to do while watching some less engaging TV. Unwound another large
toroidal mains transformer. Suspecting doubled up winding of the primary and
then for UK use joining opposite ends and so relying on 2 thicknesses of
lacquer to resist high voltage. Of course somewhere near the middle at ...matching transformer primary turns question
nanotech - 2008-12-05 04:32:00
i have a few questions to ask that someone here might be able help me
i want to design a matching transformer for my application that can
dissipate 100w operating freq 40khz
my impedance is not calculated yet i know conductor size i will be using for
primary and secondary
i know how to calcul...Uart through an audio transformer
Martin Griffith - 2008-10-04 16:26:00
Any rules of thumb about sending a 9600 baud UARTsignal ,from an 8051
through a telecom type V90 audio transformer, (LT spice K L1 L2 1 @
4mH Rs = 10R)
I only need about 8 bytes of data, and LTspice seems to need a square
wave for about a millisecond before it settles down.
So a long sync word...basic power supply
2009-03-01 17:21:00
I want to built a basic power supply with 6 7[89]?? regulators. I have
a line transformer capable of supplying 31VDC (15.5 + center-tap,
scrap transformer). However, I do not know where I should connected
the required capacitors (that is, I know they are required (and why),
but I do not how to d...Build your own Over Unity Motor
The Flavored Coffee Guy - 2008-03-14 01:17:00
Just remember this, a transformer is designed for a purpose and it can
be either a step up transformer or a step down transformer.
Everything else you need to know is here.
Go to this web site to pick up the basic theory:
http://elgersmad.homestead.com/files/resonance/transformer_motor_theor...Re: Rules of thumb for power transformer current rating - derivation?
MooseFET - 2010-01-19 09:44:00
On Jan 19, 1:02=A0am, Bitrex wrote:
> I have this document:
>
> http://www.audiofaidate.org/it/materiale/20_020_020_001_PowerTransfor...
>
> which gives rules of thumb for sizing power transformers for certain DC
> output requirements. =A0It says there are plenty of references for the...