Q:I need to run 12 amps through a 5-ohm electromagnet which means 60 volts must fall across it. I am building a power supply bridge rectifier circuit to fit my needs. I have a transformer capable of handling the wattage requirements but I am having trouble figuring out the amount of turns on the transformer to have on both the primary and secondary. The primary will be connected to an American outlet and I just don't understand how to get 60 volts DC out since the AC RMS voltage will be different than the rectified DC voltage.

If you want a different amplitude without using a resistor network, you probably need to transform before you rectify. You need a little more than half of the voltage you are starting with so not quite a 2:1 turns ratio. Make sure you have big enough wires for 60 A or they will get too hot.

Q:even in a dc transformer, the cause varying current though not in polarity, can cause a change in the magnetic flux linked with a coil.

Using a transformer with a varying DC signal was done all of the time with vacuum tube amps. Checkout the output transformer in the attached schematic and you will see its primary is being fed from high voltage(B+) DC. The output from the secondary is AC. Using a transformer is another way of blocking DC and passing the AC component of a signal. Note this doesn't mean that the DC is being pulsed on and off, rather it is varying with the applied signal. You can liken this to the algebraic sum of an AC signal with a DC bias voltage. 50VAC signal goes from +50 to - 50 volts Place that on a 100VDC and the result is a DC voltage that varies from 150V to 50V.

Q:I live in US and I will move to my home country where 240V is supplied in the power sockets.I'm planning to ship my computer, LCD TV, speakers, game console, etc. and buy a power transformer. However, I'm afraid the power loss in the transformer will raise my electric bill so in the long run, it's not worth it to ship my electrical appliances.So how much is the typical power loss in a 120/240V step up transformer? The range of efficiency would help.

In any transformer when you magnetize it your using electricity. Even if you have no load on the secondary.its just not very much.going from 240 Euro to 120 USA may not be a problem . But beware the 50HZ power supply .The actual loss for most small transformers in per cent is 12%that's 12% on the secondary. say your using 100 watts and have a lose of 12% at 120 volts the secondary amperage for this example would be [100w /120v] x 1.12.93amp the extra .12 amp is created to overcome the loss. Most computers have a switch for selection of hz and volts and a lot of tv's etc do to,,take a look before you throw em outHave a good one from the E

Q:How to measure check the good transformer ?kindly if anyone might upload the video for me . in this regarddo we have to take it out of the board ? (isolate from other components) .what to check . what should be the values ?when checking , supply should keep on or not ?any website that explain these things and upload the videos in these kind of matters . I want to learn the repairing and maintenance of electronic electrical devices instruments of daily use ?thanksGOD BLESS YOU ALL

You should compare the readings and current drawn off load with a similar transformer that is known to be good, do this, Measure the off load current at the primary with the secondary terminals disconnected, all current drawn will be due to hysteresis loss and any shorted turns. Measure the output voltage off load. Do this with both the suspected and the identical 'known to be good' transformer and expect similar results. For a double wound isolating transformer, also check for electrical separation between primary and secondary windings. Should be in the order of megohms.

Q:SGB10 transformer and SC (B) 10 transformer What is the difference between the two series where the difference, specifically to the 10 type and where the hope that the knowledge of a detailed explanation Thank you

Both transformers are dry transformers. 1, SG (B) 10 is an open dry change, he used the United States DUPONT company's NOMEX insulation paper insulation (high voltage coil, you can see is white, if it is darker that is covered with glass wire The former is American technology, the latter is German technology.) The low voltage coil is a copper foil (there is a B in the model that is made of copper foil). The same is true of B in the SC (B). High and low coils are insulated with VPI (vacuum pressure dipping). The surface of a layer of epoxy resin insulation paint wrapped up. 2, SC (B) 10 model means that the epoxy resin pouring dry change (low pressure is copper foil). The high voltage coil is sealed with an epoxy resin, but the low pressure coil epoxy is hard to pour in, but at the end of the coil is sealed with an epoxy resin. 3,10 is the design serial number, representing the loss standard value. 4, there is a dry change, model SCR (B) 10, he is non-epoxy resin casting package. All with NOMEX paper plus silicone encapsulation is the French technology. This product yield less, better quality. Maybe the price will be higher. You can also look at it. 5, is currently in the country is the three kinds of technology transformers. Epoxy resin pouring products are mostly "F" class insulation level, a few also have "H". SG (B) 10 majority is "H" level. , A few are "C" level. SCR (B) 10 is "H" level. If you still want to know what, you can give me a message.

Q:do you think transformers is cool or not and why?

I LOVE that movie, but only because the guy called Sam is hot.

Q:I can't remember the funny scenes from any the Transformers movies, especially 1 and 2.It's driving me nuts.I saw the third one just last week so I remember a couple of funny scenes, but other than that, no luck.If you can, could you please include a link to a video clip of the scene?Thanks so much! (:

I'll give you scene by scene from each movie that I can recall. I apologize for the lack of videolinks but I'll describe them as best as I can. Transformers: Bobby Bolivia (Bernie Mac) talks about his mom. Oh l love that woman if I had a rock I'd crack you in the head, b***h. Sam gets arrested and interrogated by the cops when Bumblebee runs off to communicate with the rest of the Autobots. What's this new thing they're on? Mojo? Ratchet sniffs the air when introduced to Sam and Mikaela. The boy's phermone levels suggest he wants to mate with the female. Mikaela makes Simmons take off his clothes. He has a Sector Seven t-shirt on underneath. Sam, Mikaela, Maggie, and Glen are flying to Hoover Dam. Rachel: So what did they get you for? Sam: I bought a car, and it turned out to be a giant alien robot. Who knew? Revenge of the Fallen Sam's mom and dad fooling around before their trip in front of Sam. Dad, this is not a rap video. Leo doing his funny dance while Burning Down the House is playing. Anything involving the Twins and Wheelie. Sam's mom. Oh, professor, I'd do anything for an A after eating a hash brownie (LOL! Funniest part of the movie). Simmons strips off his pants and shows he's wearing a Sector Seven cup underneath. Lennox tricks Director Galloway into parachuting off the airplane.

Q:A 1:150 transformer has a primary voltage of 4500 V. (a) What is the voltage in the secondary coil? (b) If the transformer consumes 45 W, what are the currents in the primary and secondary coils?

Transformer Problems

Q:How does the core material affect a transformer? Such as if you use steel vs. air. Or wood vs. magnet.

In 50 or 60 Hz transformers putting in a laminated magnetic iron core greatly increases the amount of magnetic flux which is generated by the primary current with the secondary on open circuit (the so called magnetising current). This enables the windings to generate a relatively high voltage with relatively small magnetising current. If you tried to make a 50/60 Hz transformer without a magnetic core (with say air or any other non-magnetic insulating material) it virtually wouldn't work because the magnetising current would be so high (the primary winding practically a short circuit). If you used a non-magnetic conducting material you'd be even worse off because eddy currrents generated in the material would prevent any flux being established and you'd have plenty of core heating but no coupling between primary and secondary. For this reason even the iron core must be laminated (unless it's non-conducting ferrite). The story is quite different for high frequencies where the inductive impedances of coils are enhanced by the frequency. There you can make quite effective air cored transformers; small ones at least - but you'd still better avoid conducting material in the core - that's what food is in a microwave oven; conducting material in the core of a high fequency transformer.

Q:The total power of 590kw, this transformer can bear it? It is best to give a formula, do not copy the.

630KVA transformer generally according to the efficiency of 0.8, about 504KW load, the capacitance compensation will increase the power factor to 0.95, the load power also increased with about 590KW near the existing total power 590kw should be installed capacity, the actual load should Less than 90% can load. 630KVA Transformer rated current: I = P / 1.732 / U = 630 / 1.732 / 0.38 ≈ 957 (A) The total installed power of 590kw, load rate or full load rate of about 0.9, the capacitance compensation to the power factor increased to 0.95 when the average power factor of about 0.9, the load current: I = P × 0.9 / 1.732 / U / COSφ = 590 × 0.9 / 1.732 / 0.38 / 0.9 ≈ 896 (A) 300kw load current (when COSφ is 0.8): I = P / 1.732 / U / COSφ = 300 / 1.732 / 0.38 / 0.8 ≈ 570 (A) Large cross-section copper wire per square safe current carrying about 2.5 ~ 3A, need to wire cross-section: S = 570/3 = 190 (square)