This has all been done. The commercial offerings include these: http://www.allegromicro.com/sf/0750/ Talk nice to them and you can get samples too. -Denny > Yeah, I know about those, but I'd like to do something at a PCB level. Those clamp meters aren't exactly small. I've been thinking something along the lines of a toroidal core with a slit cut in it (and I think those are available for instrumentation transformers) with the hall effect sensor in the middle of the cut, and what ever support hardware is necessary. > > The only problems I see are mounting the toroid so that the hall sensor fits, and the toroid is mounted to withstand some vibration. Oh yeah... And space. A toroid with a cut in it large enough for a TO-92 package isn't exactly the smallest component out there. > > Maybe it would be reasonable to mount the torroid horizontally with a hole through the PCB. and the wire running through the hole in the middle. That way you could mount the torroid with zip ties. But it's still not small. > > --Brendan > > ----- Original Message ----- > From: "M. Adam Davis" > Date: Monday, May 3, 2004 1:38 pm > Subject: Re: [EE:] Smartest binary way to detect current or no current in a cable > > > Many (if not most) clamp on ammeters already use hall effect > > sensors to > > measure current. You simply take a ring, cut a slice out of it, and > > insert the hall effect sensor. Since the magnetic field is circular, > > the ring becomes part of the magnetic field, and the hall effect > > sensorcan measure the intensity of that field. You can get the > > Radio shack > > clamp on ammeter for under $20 as a demonstration of this. > > > > -Adam > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.