Well, I had a bit of time tonight, so in hallowed hacker fashion, I took on= e of them apart. Looks like a vref chip and three TLC2272 op-amps. I put 5V= on the red and black lines, and measured 2.5xxV on the yellow and green. I= didn't have anything at my desk that drew more than mA I could reach with = the clamp as it was set up, so that will have to wait for later. The connector isn't one of the 165-12 types, it is simpler with only 6 poss= ible pin positions and a simple leg + groove type attachment rather than th= reads. For those interested, (poor) pics are here: http://www.flickr.com/photos/24004042@N03/4833170151/in/photostream/ http://www.flickr.com/photos/24004042@N03/4833782240/in/photostream/ -Pete On Jul 26, 2010, at 10:04 PM, Sean Breheny wrote: > Hi Peter, >=20 > Could it be an Amphenol 165 series connector (like the 165-12)? >=20 > Look at the bottom of this catalog page > http://www.alliedelec.com/catalog/pf.aspx?FN=3D160.pdf >=20 > also some images here: > http://www.dfwairparts.com/Amphenol.html >=20 > These are used on Tektronix current probes like the venerable A6303. > The A6303 is a DC to 15MHz probe which combines a current transformer > with a hall sensor and current feedback coil. The current in the > feedback coil is adjusted to keep the low frequency flux in the core > at near zero. The signal to drive the feedback coil forms the low freq > portion of the output signal. The remainder of what comes out of the > current transformer is the high frequency signal. These two signals > get combined (and the feedback coil current is generated) in the probe > amplifier, which is a separate module (like the AM503 or AM503A). >=20 > Sean >=20 >=20 >=20 > On Tue, Jul 27, 2010 at 12:16 AM, Peter Loron w= rote: >> I have several clamp-on current probes that I'm trying to figure out. Th= ey have a screw-on connector that looks a bit like an XLR connector. There = are 4 pins arranged in an arc across maybe 1/3 of the circumference of the = connector. >>=20 >> I'm familiar with the 2-pin probes or plain current sense transformers, = but I'm not sure what to make of this one. >>=20 >> These probes are SPX brand, but I have been unable to track down any fur= ther information about them. Presumably they go into some kind of automotiv= e diagnostic tool. >>=20 >> Any pointers from the hive mind? >>=20 >> Thanks! >>=20 >> -Pete >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >>=20 > --=20 > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .