Transformer drawing 1 amp

Started by Anonymous in sci.electronics.basics13 years ago 36 replies

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. ...

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 the transformers windings) but I took it out because I thought it might be the problem. It hums...


300 ohm to 75 ohm impedance matching "transformer"

Started by Joe in sci.electronics.basics12 years ago 3 replies

I bought a 300 to 75 ohm "matching transformer" to hook up to a home built TV antenna. The matching transformer looks exactly like the one on...

I bought a 300 to 75 ohm "matching transformer" to hook up to a home built TV antenna. The matching transformer looks exactly like the one on this URL: http://www.solidsignal.com/prod_display.asp?PROD=WMXFMRPT I have a couple of questions: Can these matching transformers be used in either direction? That is, my antenna will get the 300 ohm end, and the TV antenna input will get the ...


What is a unbalanced AC transformer?

Started by Uriah in sci.electronics.basics11 years ago 4 replies

I need to provide a 10VAC power supply to a cirris cable tester and they said it was unbalanced. It is a three pin input with the center being...

I need to provide a 10VAC power supply to a cirris cable tester and they said it was unbalanced. It is a three pin input with the center being neutral and each side is hot 10VAC but it is unbalanced. What do they mean by unbalanced? How would I wire that up? And is there a way to tell how to wire it in from looking at the device, I don't have the that power supply. Thanks Russ


Villard circuit and transformer question

Started by Daku in sci.electronics.basics9 years ago 8 replies

Could some electronics guru provide some insight into the following ? One can use a Villard multiplier to step-up voltage and a...

Could some electronics guru provide some insight into the following ? One can use a Villard multiplier to step-up voltage and a capacitive divider to step-down voltage. However, most power supplies still use a transformer for voltage step-up/down. What is the inherent deficiency of a Villard circuit that prevents it from being used for these purposes. Thanks in advance for your feedback.


transformer winding ratio question

Started by panfilero in sci.electronics.basics8 years ago 3 replies

I have a basic question about transformer ratios, if I have 3 windings, a pri, a sec and an aux, what's the voltage expression for each winding?...

I have a basic question about transformer ratios, if I have 3 windings, a pri, a sec and an aux, what's the voltage expression for each winding? My guess is Vpri = Npri/Nsec Vsec = Nsec/Npri Vaux = Naux/Npri is this right? thanx!


Step Up Pre Coil/Transformer

Started by Bret Cahill in sci.electronics.basics8 years ago 3 replies

OK Honda no longer makes the original ignition coil that steps up the voltage by 3 -4 orders of magnitude. What's the easiest way to get a...

OK Honda no longer makes the original ignition coil that steps up the voltage by 3 -4 orders of magnitude. What's the easiest way to get a 40,000 volt spark out of a 12 volt ac system with a 100X step up coil? Bret Cahill


Powerline Networking Question

Started by Anonymous in sci.electronics.basics8 years ago 4 replies

With this technology can you supply a neighbor with internet if they share the same utility power transformer?...

With this technology can you supply a neighbor with internet if they share the same utility power transformer? Thanks! http://www.newegg.com/Product/Product.aspx?Item=9SIA0MC0AS7586&Tpk=9SIA0MC0AS7586&nm_mc=EMC-GD06 1512&cm_mmc=EMC-GD061512-_-index-_-Item-_-9SIA0MC0AS7586


Center Tapped and Regular Transformer

Started by Anand P. Paralkar in sci.electronics.basics8 years ago 39 replies

Hi, Could you please explain the following points regarding a center tapped transformer (some questions apply to a non-center tapped...

Hi, Could you please explain the following points regarding a center tapped transformer (some questions apply to a non-center tapped "regular" transformer as well): a. Is the center tapped transformer wound differently than a non-center tapped transformer? Or is it just a regular transformer for which the center point of the secondary winding is "brought outside". b. Consid...


High-frequency power sine wave generation

Started by Don Gilmore in sci.electronics.basics8 years ago 3 replies

Guys: I'm working on an application where I need to drive a small transformer wit= h high frequency AC power (like around 20 kHz) at about 24...

Guys: I'm working on an application where I need to drive a small transformer wit= h high frequency AC power (like around 20 kHz) at about 24 volts or so. My = power comes from a 120/24 transformer. In the embedded circuit is an Atmel = microcontroller which can produce a 20 kHz, 5V square wave. I need the lit= tle transformer to deliver about 4 VA. Is there an easy way to do this? I h...


What is VA...ref. transformers

Started by chas in sci.electronics.basics8 years ago 19 replies

Checkiing to buy a transformer, I see most of them don't publish the output amps but do give a stat 'VA'. Is this just wattage?. .. .chas

Checkiing to buy a transformer, I see most of them don't publish the output amps but do give a stat 'VA'. Is this just wattage?. .. .chas


Distribution Transformer

Started by Servo Kon in sci.electronics.basics7 years ago 6 replies

Distribution transformer aims to provide well tailored-solutions of all kind of voltage dilemma. We walk by holding the hands of...

Distribution transformer aims to provide well tailored-solutions of all kind of voltage dilemma. We walk by holding the hands of latest technology and techniques to learn and implement them in our products. Today, voltage fluctuation has become a serious problem causing the loss of quality in the products thereby affecting the production. For more information visit on :http://www.distributi...


Talema toroidal transformer

Started by eatmorepies in sci.electronics.basics7 years ago 38 replies

I have a toroidal transformer. It is marked: Talema TVR 2518 7702-P2S2 486 I have failed to find a data...

I have a toroidal transformer. It is marked: Talema TVR 2518 7702-P2S2 486 I have failed to find a data sheet using Google - anyone any ideas where I might find a data sheet? There's 8 wires: blue, brown. pink, pink, red, yellow, green and purple. John


Reactive load impedance in a transformer (Circuits I don't understand #1)

Started by M. Hamed in sci.electronics.basics7 years ago 12 replies

Having a resonant circuit in the secondary of a transformer has been bother= ing me for quite some time. Circuit books teach that a transformer...

Having a resonant circuit in the secondary of a transformer has been bother= ing me for quite some time. Circuit books teach that a transformer will tra= nsform the impedance by square of the turn ratio. Wes Hayward in "Introduct= ion to RF Design" says that this holds true even when the impedance is reac= tive. This is either misleading or I am confused. Wouldn't that mean that if you = h...


Need an Isolation Transformer?

Started by amdx in sci.electronics.basics7 years ago 7 replies

I needed isolation from the line today, it reminded me of something I learned while building a Cockcroft-Walton high voltage generator. Use...

I needed isolation from the line today, it reminded me of something I learned while building a Cockcroft-Walton high voltage generator. Use two transformers back to back. Example, you have two 120V to 12V transformers, (120v in 12 out) connected to (12v in and you have 120V out). Or any two transformers with the same secondary voltage. Current limit depends on the transformer size. It wo...


What is this chip from broken electric fence?

Started by Butter in sci.electronics.basics6 years ago 15 replies

This is a small electric fence set up for livestock. I used it to keep foxes away from my ducks in past and now try to keep dogs in. My dog...

This is a small electric fence set up for livestock. I used it to keep foxes away from my ducks in past and now try to keep dogs in. My dog kept going through it and I found it wasn't working. I only have checked the wire to ground as far as working. DOg checked it also and she says it don't work and I can run loose. All there is to it is a transformer and something shaped like a big capac...


Current runaway in power inverter circuit.

Started by Don Gilmore in sci.electronics.basics6 years ago 6 replies

Hi guys: I'm an ME doing a little EE work. I'm testing a circuit that is basically a= power inverter.=20 I start with 24Vdc and a...

Hi guys: I'm an ME doing a little EE work. I'm testing a circuit that is basically a= power inverter.=20 I start with 24Vdc and a transformer primary (ferrite core) with a center t= ap. The center tap is connected to +24V. Each end of the primary is connec= ted to a n-type power MOSFET (with a very low Rds) each of which connects t= o ground. I fire the MOSFET's alternately using a fun...


Flyback converter

Started by Patrick Chung in sci.electronics.basics6 years ago

Even though some authors presents flyback converter as transformer isolated boost converter, it is more closer to reality that flyback dc-dc...

Even though some authors presents flyback converter as transformer isolated boost converter, it is more closer to reality that flyback dc-dc converter can be explained as transformer isolated buck-boost converter. Read more: http://www.cirvirlab.com/index.php/switching-mode-power-supply/132-flyback-dc-dc-converter-basic s.html Also, simulate flyback converter online on http://www.cirvirl


Another old Pioneer SX-434 question-speakers

Started by Anonymous in sci.electronics.basics6 years ago 3 replies

Thanks to all those who replied to my last questions about my old SX-434. I have done everything advised except actually powering it up. I have...

Thanks to all those who replied to my last questions about my old SX-434. I have done everything advised except actually powering it up. I have decided to power it up slowly by using my nice isolated output Staco variable transformer. I do not as yet have speakers for the thing and will be looking for some used ones. Besides being 8 ohms what should I look for? I have always bought speakers a...


Forward converter is actually transformer isolated buck (step down) converter.

Started by Patrick Chung in sci.electronics.basics6 years ago

Read more: http://www.cirvirlab.com/index.php/switching-mode-power-supply/143-forward-dc-dc-converter-basic s.html Also, simulate forward...

Read more: http://www.cirvirlab.com/index.php/switching-mode-power-supply/143-forward-dc-dc-converter-basic s.html Also, simulate forward converter online on http://www.cirvirlab.com/simulation/smps_forward_dc_dc_converter_online.php


Step-down transformer backward?

Started by Fester Bestertester in sci.electronics.basics6 years ago 35 replies

I have this transformer: http://www.signaltransformer.com/sites/all/pdf/M4L.pdf model M4L-2-10, 210/230/250 primary with 115 secondary....

I have this transformer: http://www.signaltransformer.com/sites/all/pdf/M4L.pdf model M4L-2-10, 210/230/250 primary with 115 secondary. Is it safe to use it in reverse to get 230v from 115 mains? This is in N. America. Thanks.