How to convert a current transformer to a digital switch

[igeorge]

Hello,
I have a Coilcraft current transformer which give me 10 to 50 mv AC for 1 to 5 Amps .
I need to convert the output to a digital 1 or 0, current through, no current
0 = no current
1 = current
In this case if the current transformer give me anything over 10 mv i must get an 1. I mean by 1 the +5vdc to feed to a microprocessor input.
I do not know anything about operational amplifiers, comparators, and the rest.
I would like if somebody have a schematic with parts and value, that i can put it in a breadboard and test it.
Thank you
Ion

[mat janssen]

Use a comperator for this problem.
You can use the buildin comperator when using thi right chip, or a LM311 when using an external one.

[mister_e]

http://www.bristolwatch.com/ele/vc.htm

If speed is not an issue, you could also use a spare ADC pin of your PIC and some IF THEN.

[igeorge]

Thanks to every one for suggestions.
My problem here is that the current transformer give me 10 mv AC, which will be 5 mv ac if i take only the positive side of it.
The output also it is a sine wave, so first i have to converted in DC , which will result in a pulsating 5 mv wave at 60 hz.
Then i have to convert that pulsating voltage in a dc line voltage, and in the final to use a comparator.
I tried to use a bridged rectifier for the 10 mv output and i got nothing, almost zero. I assume because the voltage is drooped across the diodes.
I read the page for comparators, but until i can use it, i need to get some kind a decent DC voltage to it.
Any suggestion ?
Best regards
Ion

[mister_e]

use an operational amplifier in non-inverted mode. give it a decent gain, and play 'round it

[Pic_User]

Hi Ion,
Put several turns thru the PRIMARY of the Current Transformer
Full-wave-bridge rectify the secondary (don’t forget the “burden” resistor), put a capacitor on DC from FWB (=peak) use this peak to turn a bipolar transistor on (0.65V). Use the transistor’s Collector / Emitter to pull a logic pin.
-Adam-

[igeorge]

This is an other issue of my current transformer Adam. The CT i use, is a PCB type and gives 10 mv for an amp up to 50 mv for 5 amps.