rectifier using mosfet

[nocky]

hello

I am designing a power supply for powerline robots, i'm using qfield to design a current transformer. I'm getting a low ac voltage 1V and i need to rectifier it, i have read that i can use mosfet for rectification...I'm not sure hhow to go about designing it... anyone who can help or pdfs to read thru...plz.

thank u
Nocky

 

[tpetar]

Theta Engineering: Design Ideas: FET Bridge

 

[FvM]

As a first point, I don't exactly understand the motivation of your question. The output of a current transformer is basically a current rather than a voltage. Of course, the available voltage is limited according to the maximum core flux.

Secondly, I fear you'll get difficulties to operate a self-steered MOSFET rectifier with low voltages of e.g. 1 V, because MOSFET threshold voltages are usually higher.

In my view, there are two common solutions for rectifying current transformer output:
- if an output voltage of e.g. 1 V can be accepted, use low voltage schottky diodes
- for lowest transformer voltage (respectively best accuracy), use active rectifier circuits with operational amplifiers or optionally preceeding AC amplification

 

[alexxx]

You could also take a look at precision rectifiers (using operational amplifiers):

**broken link removed**
**broken link removed**
http://www.site.uottawa.ca/~rhabash/ELG4135L8.pdf