At 12:17 PM 9/10/2009, you wrote: >----- Original Message ----- >From: "Spehro Pefhany" >To: "Microcontroller discussion list - Public." >Sent: Thursday, September 10, 2009 7:49 AM >Subject: Re: [EE] two wire inductive magnetic gear tooth sensor circuitry > > > > At 11:12 PM 9/9/2009, you wrote: > >> > The OP has not provided enough information to allow anyone to do more > >> > than > >> > make guesses at what he has and what he needs. > >> > >>I would strongly recommend that the original poster see what happens if he > >>treats the sensor as a current loop device: > >> > >>Connect +24V to +ve lead of sensor > >>Connect -ve lead of sensor to load resistor (250 ohms or so) > >>Connect other lead of load resistor to ground > >>Scope signal across load resistor > >> > >>If the device is indeed 4-20ma current loop, then the signal should swing > >>somewhere between 1 and 5 volts. > >> > >>-- Bob Ammerman > > > > If the signal goes up to a large DC value, slowly changes over the next > > few minutes, then makes an abrupt change, then you know it is > > (was, actually) a VRS. ;-) > >The OP has *already* applied 24V to the sensor (without a series resistor) >and it seems to generate a low-level sinusoid(?) superimposed on the supply >voltage. Bob-- maybe he had the sensor in series with the 24V supply and was reading the voltage wrt ground, which would yield the results he observed. If he said clearly otherwise, I must have missed it. Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist