There are different types of instrument transformers. some for measuring and some for protection (such as class 0.1, 0.2, 0.5,...and 5P, 10P ). There is class A as well. I need to know about class A in voltage transformers. Where can I find refrences. What are the specifications and so on.
200158
Class A transformers include the following:\nHigh and low voltage Switch gears,voltage and current monitors,voltage regulators ,stabilizers and detectors,voltage insulators,controllers , calibrators.\nRefer to Alfa Transformers limited, Gogate eletro systems, and Neel Industrial systems.
131404
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322336
hi,\n\nas i understand it, the way a DC-DC converter operates is in 3 stages:\n\nfirst, V_in is used to drive a pair of coupled transistors (or some other oscillatory circuit) that output a square wave or some kind of time-varying oscillatory voltage.\n\nsecond, that AC signal is used to drive a transformer which consists of two inductors.  the ratio of the number of turns in the primary and secondary windings of the transformer determines the step-up or step-down ratio of the transformer.  if you have a 3:1 inductor then you will step down the voltage by a factor of 3, for example.\n\nthird, the transformed AC signal gets converted to DC by a bridge rectifier or some other AC->DC circuit.  generally speaking, a bridge will output a DC voltage that is simply proportional to whatever AC you put into it.  (of course if you way over- or under-drive it, it won't work right.)\n\nanyway, if you have a single missing turn on either side of your transformer, that will change the step-up/down ratio.  my 3:1 example would become a 2:1 transformer and then you'd get an output voltage that was too high (1/2 of the input, instead of 1/3).  \n\nthen the rectifier will just flatten out whatever voltage you put into it.\n\nhope this helps!
31444
Those guys (arc welding power supplies) have high voltage inside, but they output low voltage at high current.\nTry old neon transformers, oil burner ignition transformers (but you need some high-voltage diodes for DC), a discarded TV set (but very dangerous, HV can be stored in various places when you open it). \nFor battery ops you might be able to gin something up with an ignition coil and some sort of primary current interrupter but you'll get pulses, not DC. If you're into DIY, you can rip the flyback transformer from a TV and follow the directions in the ref. Many more such projects if you google High Voltage Inverter". Good luck.
593697
Technically, you don't convert mA into VA in any AC circuit!  One is a measure of current flow, the other is a measure of power.\n\nNow if you want to figure out the power of the transformer, simply multiply the amperage by the voltage.\n\nP = 12V X 800mA = 12V X 0.8A = 9.6 VA or 9.6 watts.\n\nNow you can think of the power in terms of VARs (volt amp reactive), but those are typically used in where you have either a(an) inductive and/or capacitive load and use imaginary numbers to solve such problems.
188925
As you must be aware, the voltage on an AC line varies sinusiodally with time. ( it goes from 110v to -110v 60 times a second for a standard wall outlet in the US ). that is why it is called Alternating Current.\nhttp://en.wikipedia.org/wiki/Image:Sine_wave.png\n\nA single AC voltage line and a ground line together are a single phase supply. simple.\n\nNow if you take three cables, with voltages varying over them sinusiodally, you have 3 phase supply :). wish it were that simple though. \n\nnow all three sinusoids will reach their peaks simultaneously, and zeroes simustaneously. the instantaneous power on all the lines would be zero at that point. you can avoid this (and is practically more useful to do so) by staggering these sinusoids, so that they reach 0 at different times. the time by which you stagger them is called the phase difference. the standard is to stagger them by 120 degrees as shown here\nhttp://en.wikipedia.org/wiki/Image:Three_phase_voltages.png\n\nthere you are. hope that is cleared up for you :)
363225
Here is a good article. To understand them, you need to get a multimeter, and electronics projects book, a breadboard (to mount circuits on), and a selection of electronic parts from Radio Shack. Use batteries initially, and then when you are more confident a power supply and rectifier to do experiments, and measure voltage, current, and resistance values around the circuit.\nhttp://en.wikipedia.org/wiki/Electronics\nHyperphysics. (Google)\nhttp://www.mathworld.wolfram.com\nhttp://www.refdesk.com\n"You can do it electronics," Needham Heights, MA\nEnjoy!
484067
An ideal voltmeter has infinite resistance: It is an open circuit. Although it is impossible to make a physical voltmeter with infinite resistance, a well designed voltmeter exhibits a very large internal input resistance. In some experiments, it is important to take into account the finite, non-ideal, internal resistance. To determine the internal resistance of the voltmeter, set up the circuit shown in figure . The voltmeter reads the voltage across itself, which includes its internal resistance. Since the circuit has only a single branch, the current flowing through the resistor also flows through the voltmeter.\n\nFor the required formulas and schematics, check out the reference.
424803
For all steam and gas turbine... you need a circuit breaker. But it is only the matter of designing before or after the transformer and how safe you want to the system to be
601076
Perhaps the link will help.  At a minimum, you risk voiding your warrant if you use other that the voltage and frequency required on the unit name plates.  At worse you risk injury and a possible fire if you really don't know what you are doing.  Good luck.
165602
400 Hz transformers, motors and generators are always smaller and lighter than their 60 Hz equivalents. The motors and generators use lower-inductance windings and tend to operate at higher rpms and lower torques. However, according to the ref., this weight savings comes at the cost of lower efficiency due to greater wiring inductive loss at higher frequency.
47074
10mH is 10 milli-Henries.  A Henry is a measure of inductance, and is defined as L=di/dt.  Inductors resist changes in current flow.  You have to use calculus to get the equation for an RL (resistor-inductor) circuit, which is what you have.  You are subjecting an RL system to a step input of 10 V from a "voltage source."  See the more technical, long-winded explanation of inductance.\n\nThe second site actually shows you an animated plot of the exact ciruit you are interested in.  \n\nAs a note of interest, large iron core inductors were developed for power supply filters in Vacuum Tube radios and amplifiers.  They had huge inductances of 7H or more.  These days, everything is in microhenries or millihenries because the frequencies in today's electronic systems have gone past 1 gigahertz.  Inductors can act as frequency-dependent resistors.  \n\nThese days, one hugely popular use of an inductor is to store energy in a magnetic field for switching power supplies in conjunction with electrolytic capacitors and FET modulated drives.  Wound 60Hz transformers are quite expensive, large, and heat producing.  The days of linear power supplies with large iron core transformers have given way to tiny circuits with driving transistors, an inductor, and some capacitors.  Switching supplies running at 125kHz or more can use transformers with ferrite (powdered iron) cores and far fewer windings.  The higher frequency packs much more energy than a 60Hz electrical source.\n\nAs a point of interest, try to find an old computer power supply which should be very easy to get.  Open it up.  Look at the parts, and you will see a high frequency transformer, inductors, capacitors, and drive transistors with modulating chips.  The 120VAC from the wall is put through 4 diode rectifiers to make 169V DC with some high voltage capacitors.  This voltage is made available to be switched at relatively high freqencies into a powdered core transformer primary.  The Secondary makes high frequency AC voltage which is rectified and filtered with capacitors and/or inductors.  A voltage detector circuit, usually isolated from the high voltage DC side by an optical isolator, tells the modulating chip what the load is.  The modulator will then vary the duty cycle of the transistors at a constant frequency to move more power across the transformer.  Have fun with electronics!  I love it...
128687
Explain how a PIN diode works.\n\nWhat is the impact of lead length on the input of a preamp?\n\nHow does Signal/Noise affect an amplifiers sensitivity?\n\nWhat are the watts loss for a voltage regulator?
540285
a Nm (Newton-meters) is a J(oule)\n...\n> Message: I know Nm is joules and joules per\n> second is watts. \n\nCorrect.\n\n> But how do i know the ampere, volt and ohms?\n\namps = Watts/volts\nvolts = Watts/amps\n\nvolts = ohms * amps \n(ohms law)
38121
got a dandy.....even though  it  seems  difficult   youll  break through  and  find  out  you can  almost  measure  anything....try  this  because  i dont  know  what  type  of  equipment  you have....in  search  bar  go.....vernier  read .. hit search..the  NTNU site java  is  excellentyou you can  even  practice  measuring  on  line.....reading  a  vernier  is  good too.....check  them  all
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They don't say what they are because you are suppose to get a copy of B31.9 and follow its requirements. \n\nB31.9 can change from time to time and this way the specification is always current. If the specification spelled out B31.9 and then quoted the requirements and they had changed in the mean time there would be a conflict.\n\nI have written many specifications for piping and this is the only way to be sure B31.9 or other industry standards are met.
112744
v=voltage\no=ohm\nm=milliammeter\n\na tester which test those mentioned aboved. don't use it in measuring resistance(ohms) when the circuit is still connected to a source (voltage)