Hi, I'm trying to sort out a problem with my homebrew battery charger, which seems to only occur when it's hooked up to the ICD2, and even then it only happens when the ICD2 is hooked up to my desktop machine. When the ICD2 is connected, the +5V power bus picks up a 0.5V amplitude repeating pulse, with a period of about 100us. Unplugging the ICD2 from the PC, or plugging it into a laptop instead of the desktop system completely removes the noise. Besides "use the laptop", can anyone suggest a way of getting rid of this noise? It's causing major problems with the opamps in the V/I sense circuit -- the noise is going from the Vcc supply to the opamp output. Needless to say this makes a bit of a mess of the current readings and usually causes the SMPSU to lose regulation. I managed to capture the noise on my scope - see . Adding capacitors to the supply lines doesn't seem to do anything - I've tried everything I had from 100nF to 470nF, 1uF to 100uF, and a 1000uF low-ESR I had lying around. The noise is still there... Short of giving up on debugging this thing with my desktop machine and switching to the laptop (which would involve me reinstalling MPLAB), can anyone suggest anything else I could try that might get rid of (or at least severely attenuate) the noise? Thanks. -- Phil. | Kitsune: Acorn RiscPC SA202 64M+6G ViewFinder philpem@dsl.pipex.com | Cheetah: Athlon64 3200+ A8VDeluxeV2 512M+100G http://www.philpem.me.uk/ | Tiger: Toshiba SatPro4600 Celeron700 256M+40G -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist