Neon signs (which often contain gases other than neon) use high voltage to excite gaseous atoms that then give off a characteristic glow. When plugged into a wall outlet (120 V AC), a typical neon sign transformer delivers 400 W AC at a voltage of 18 kV rms. The primary coil has 400 turns. 1. First, what is the number of turns in the secondary to achieve this high voltage? Give your answer to 2 significant digits. 2. Next, if the transformer is ideal, what is the rms current in the primary? Give you answer in amps with 2 significant digits. 3. Finally, what is the rms current in the secondary? Give your answer in milli-amps with 2 significant digits.

Neon signs (which often contain gases other than neon) use high voltage to excite gaseous atoms that then give off a characteristic glow. When plugged into a wall outlet (120 V AC), a typical neon sign transformer delivers 400 W AC at a voltage of 18 kV rms. The primary coil has 400 turns. 1. First, what is the number of turns in the secondary to achieve this high voltage? Give your answer to 2 significant digits. 2. Next, if the transformer is ideal, what is the rms current in the primary? Give you answer in amps with 2 significant digits. 3. Finally, what is the rms current in the secondary? Give your answer in milli-amps with 2 significant digits.

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.57P: A two-winding single-phase transformer rated 60kVA,240/1200V,60Hz, has an efficiency of 0.96 when...

See similar textbooks

Similar questions

Consider Figure 3.25 of the text for a transformer with off-nominal turns ratio. (i) The per-unit equivalent circuit shown in part (c) contains an ideal transformer which cannot be accommodated by some computer programs. (a) True (b) False (ii) In the - circuit representation for real c in part (d), the admittance parameters Y11 and Y12 would be unequal. (a) True (b) False (iii) For complex c, can the admittance parameters be synthesized with a passive RLC circuit? (a) Yes (b) No
Consider two interconnected voltage sources connected by a line of impedance Z=jX, as shown in Figure 2.27. (a) Obtain expressions for P12 and Q12. (b) Determine the maximum power transfer and the condition for it to
The failure of power transformers is assumed to follow a Poisson probability distribution. Suppose on the average, a transformer fails once every 10 years, what is the probability that it will not fail in the next 12 months? once in the next 24 months? One thousand new OCRs are put in service. They have a constant failure rate 0f 0.05 per year. How many units of the original 1000 will still be in service after 5 years? How many of the original will fail in Year 5?
A Step-Down Transformer. A transformer connected to a 120 V (rms) ac line is to supply 12.0 V (rms) to a portable electronic device. The load resistance in the secondary is 5.00 Ω. (a) What should the ratio of primary to secondary turns of the transformer be? (b) What rms current must the secondary supply? (c) What average power is delivered to the load? (d) What resistance connected directly across the 120 V line would draw the same power as the transformer? Show that this is equal to 5.00 Ω times the square of the ratio of primary to secondary turns.
You are given five light bulbs designed to operate on 160 mA current at 3.0 V (rms values), arid want to connect them in parallel, through an ideal transformer, to 120 V rms AC household power. a) Draw a circuit diagram showing the AC power source (a generator symbol ), the transformer, and resistors for the light bulbs. b) Is the required transformer step-up or step-down? What turns ratio N5/N is needed? e) Calculate the ruts current through both the primary and secondary coils of the trans former, in mA.
The following data were obtained from a short-circuit test performed upon a 50 kVA, 2300/115 V, 60 Hz transformer: Esc = 87 V, Isc = 21.75 A, Psc = 590 W. Calculate (a) equivalent resistance, reactance and impedance referred to the primary, and (b) voltage regulation at a power factor of 0.866 lagging. Subject: Electrical Apparatus and Devices
A 400-turns auto transformer, operating in the step-down mode with 25 percent tap supplies a 4.8 kVA, 0.85 lagging power factor load. The input to the transformer is 2400 V, 60 Hz. Neglect the small losses and leakage effects. What will be the apparent power(in kVA) conducted and transformed respectively?
A Step-down transformer at Van Eck power station in Windhoek operates at V=10 kV on the primary side during wintertime. The voltage drawn from the secondary side of the transformer is V = 118 Volts. What is the current in Amps, on the secondary side of the transformer if the average rate of energy consumption demand is at 112.3 kW?
A 120:480-V, 10-kVA step-up two-winding transformer is to be used as an autotransformer to supply a 120-V circuit from a 600-V source (a step-down autotransformer). When it is tested as a two-winding transformer at rated load, unity power factor, its efficiency is 97.9 %. 1.Show the connection diagram of the transformer converted as an autotransformer and identify which is the series winding Nse and the common winding Nc.
A 10 kVA, 500/250 V, single phase transformer has its maximum efficiency of 94% when delivering 90% of its rated output at unity p.t. Estimate its efficiency when delivering its full load output at p.t. of 0.8 lagging,
A 240-kVA, 480/4800-V, step-up transformer has the following constants: Rs = 2.5 Ω, Xs = j5.75 Ω, Rp = 25 mΩ, Xp = j57.5 mΩ. The core-loss resistance and the magnetising reactance on the high-voltage side are 18 kΩ and j12 kΩ, respectively. The transformer is operating at 50% of its rated load. If the load is purely resistive, determine the percent power efficiency of the transformer
Q 03: Briefly discuss, how the energy consumptions for operations of a fork lifter could be justified. Suppose that a fork lifter has a total energy consumption of 150 W.Hr. The total trips of the vehicle are 375. How the battery duty cycle may be calculated in this case?