Hello All...I would like to ask something based from the attached circuit...So, let say the load from the secondary of signal transformer got shorted, can it blown the fuse at primary side? My own view it should not because they are isolated but please share your thoughts on this....thanks
Yes, depending upon the primary and secondary resistance.
What do you think determines the primary current?
The galvanic isolation that a transformer provides has nothing to do with the primary current.
The primary current is determined by the secondary current multiplied by the transformer turns ratio.
There are two options:
1. The fuse has been correctly chosen for the rated transformer current. Then it will surely interrupt an output short.
2. The fuse is massively oversized. Depending on the transformer impedance, either the fuse blows or the transformer burns.
Where and how did you measure and what result did you get?
and especially for transformers:
* "Resistance" is one thing (measured with DC)
* "impedance" is onother thing (measured with AC)
a transformer is used on AC only.
Thanks a lot to all....I managed to find the root cause of blowing fuse. The fuse connected to 4 components in parallel. The dc module, 2 signal transformers(step down), and a high voltage transformer 4800V. I isolated one by one and power-up independently. Only the high voltage transformer drawn current up to 10A. But the fuse only 3A. I made a video on my channel and share, hoping someone can learn, thanks -->