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How does a secondary resistor affect the transformer primary?
The transformer, containing no resistance in either primary or secondary windings, itself dissipates no power. So in order to conserve energy, the power supplied to the load must equal the power furnished by the primary source. So V 22 /R 2 = V 12 /R 1. So the primary source MUST “see” R 1 = (V1/V2) 2 R 2 = 2 2 R 2 = 20Ω.
How are the primary and secondary windings of a transformer connected?
Both the primary and secondary coil windings are wrapped around a common soft iron core made of individual laminations to reduce eddy current and power losses. The primary winding of the transformer is connected to the AC power source which must be sinusoidal in nature, while the secondary winding supplies electrical power to the load.
How is the resistance of a transformer determined?
Let’s explain it this way. If you get a length of wire, say 120 metres, it will have a resistance, say 120 ohms and if you connect it to a 240v AC supply, a current of 2 amps will flow, according to Ohm’s Law. For this discussion, the voltage must be AC.
How many turns does a single phase transformer have?
A single phase transformer has 480 turns on the primary winding and 90 turns on the secondary winding. The maximum value of the magnetic flux density is 1.1T when 2200 volts, 50Hz is applied to the transformer primary winding. Calculate: a). The maximum flux in the core.
Considering a resistive load R on the secondary, the effective resistance as seen by the primary source will depend upon the turns ratio of the primary and secondary coils of the transformer.
Is it okay to use a power resistor in series?
A resistor in series with the primary side of the power supply would be weird, doubly so because it isn’t in the service manual / schematic. Using a power resistor like this to prevent the fuse from blowing first is, in my opinion, a fire hazard.
How to calculate reflected load in a transformer?
Once this reflected load is evaluated, the circuit can be considered like a simple resistive series circuit. The treatment here will assume an ideal transformer. Treating the circuit as if the primary were a simple series resistor RP, the effective value of that resistor can be calculated from Ohm’s law and the transformer relationship.