Another thought. Put a few turns of fine wire around the current carrying conductor, and feed it to the input of an opamp (or comparator). Feed the output of the opamp into the trigger input of a one shot set for 100ms or so. Then you'll be able to see the pulse because the oneshot is acting as a pulse stretcher. Just a thought. =20 =20 Regards, Jim > -------- Original Message -------- > Subject: Re: [EE] Detecting magnetic pulses > From: David > Date: Wed, September 07, 2011 3:43 pm > To: "Microcontroller discussion list - Public." >=20 >=20 > On 06/09/2011 23:59, jim@jpes.com wrote: > >> -------- Original Message -------- > >> Subject: [EE] Detecting magnetic pulses > >> From: David > >> Date: Tue, September 06, 2011 3:38 pm > >> To: "Microcontroller discussion list - Public." > >> > >> > >> I am building a very simple magnetic pulse circuit, which sends a shor= t > >> (1uS) pulse through a coil wrapped round a solid core (using a FET). > >> This is a near exact copy of a circuit I was given which needed some r= epair. > >> > >> What I don't have is the coil & detector circuit which picked up these > >> pulses, or a schematic. > > > > Put a magnetic compass beside the wire and send the pulse. If it is > > working, A magnetic field will be set up and cause the compass to > > spin. >=20 > Thanks Jim, this does work. Albeit only at very close distances right > now, so I can work from there to try and increase the range with a > variety of cores/wire wraps etc. >=20 > The current is fairly low (9v battery and a 100R resistor) and it is > pulsed very quickly. However as tested the board I copied works from a > few inches. Just need to tweak my coil/core. >=20 > Cheers, >=20 > David > --=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 .