gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
170711-0920 EDT
Sahib:
You need to get down to basics. Somehow you are not corrrectly looking at a basic loop equation that sums to 0.
I set up a simple experiment with an AC voltage source, 60 Hz power line at reduced voltage, a 75 ohm resistor in series with a 175 VA 120 V transformer primary, and an oscilloscope. The reason for the reduced voltage was to minimize transformer saturation current. The voltage channel used a 10x probe. Thus, peak voltage was about 18 V. Peak current about 5 mA. As a side note: the distortion of the voltage peak is not seen in the current waveform because of the filter action of the inductance.
In the scope plot you see a single shot display of a steady state condition of the series RL and AC source circuit. Note the lagging phase shift of the current.
mivey has told you and you should have on your own known that there is voltage drop across the resistance when the AC source voltage is zero. That this is true is easily seen in the scope plot. Following is the plot with blue being source voltage, and red being being the voltage across the 75 ohm resistor. There is also about 1.5 ohms resistance internal to the transformer. The phase shift is about 45 deg.
.
Sahib:
You need to get down to basics. Somehow you are not corrrectly looking at a basic loop equation that sums to 0.
I set up a simple experiment with an AC voltage source, 60 Hz power line at reduced voltage, a 75 ohm resistor in series with a 175 VA 120 V transformer primary, and an oscilloscope. The reason for the reduced voltage was to minimize transformer saturation current. The voltage channel used a 10x probe. Thus, peak voltage was about 18 V. Peak current about 5 mA. As a side note: the distortion of the voltage peak is not seen in the current waveform because of the filter action of the inductance.
In the scope plot you see a single shot display of a steady state condition of the series RL and AC source circuit. Note the lagging phase shift of the current.
mivey has told you and you should have on your own known that there is voltage drop across the resistance when the AC source voltage is zero. That this is true is easily seen in the scope plot. Following is the plot with blue being source voltage, and red being being the voltage across the 75 ohm resistor. There is also about 1.5 ohms resistance internal to the transformer. The phase shift is about 45 deg.
.
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