mrinalmani
Advanced Member level 1
- Joined
- Oct 7, 2011
- Messages
- 463
- Helped
- 60
- Reputation
- 121
- Reaction score
- 58
- Trophy points
- 1,318
- Location
- Delhi, India
- Activity points
- 5,285
Hi
I've wound a simple current transformer with 1:100 turn ratio using a small toroidal nanocrystalline core.
It more or less works OK, but there are two issues.
1. The current aligns to voltage at every cycle end but goes goes slightly out of phase during falling slope of the voltage. (Please refer to attached figure)
2. The secondary current drops suddenly if the value of primary current exceeds about 5A RMS. This causes severe distortion.
In my measurement setup, there's an auto-trasnformer connected to a 25Ohm resistive load and the primary current is varied by varying the transformer knob. The oscilloscope probes are connected to:
(a) the voltage across 25 Ohm load
(b) the voltage across burden resistor which is 1 Ohm. (Secondary winding resistance is 2 Ohm, so total burden = 3 Ohm)
Yellow is primary current and blue is secondary current.
Any one with experience in current transformers please help.
Thank you
I've wound a simple current transformer with 1:100 turn ratio using a small toroidal nanocrystalline core.
It more or less works OK, but there are two issues.
1. The current aligns to voltage at every cycle end but goes goes slightly out of phase during falling slope of the voltage. (Please refer to attached figure)
2. The secondary current drops suddenly if the value of primary current exceeds about 5A RMS. This causes severe distortion.
In my measurement setup, there's an auto-trasnformer connected to a 25Ohm resistive load and the primary current is varied by varying the transformer knob. The oscilloscope probes are connected to:
(a) the voltage across 25 Ohm load
(b) the voltage across burden resistor which is 1 Ohm. (Secondary winding resistance is 2 Ohm, so total burden = 3 Ohm)
Yellow is primary current and blue is secondary current.
Any one with experience in current transformers please help.
Thank you