How did you decide how large the spikes were? with a scope probe? I'm suspicious of the size of the spikes; power supply filters should crush a spike that size...Can't you clamp the regulator output with a transzorber or TVS? Maybe you need to look at the PIC port lines and see if you can install a few RC filters, cause perhaps the RF is radiating into the PCB past the power supply (my guess). --Bob Shawn Wilton wrote: >More inductive or capacitive filtering elements on the power line *near* the >chip. > >On 1/25/06, andrew kelley wrote: > > >>Hello all, >> >>I have a solid state relay controlled by a 'c508 which is powered from >>a simple power supply (transformer, rectifier, regulator with 470uF >>cap on input and 10uF on output). We have a microwave which when you >>open or close the door generates +/- 0-8v spikes on the power *to the >>micro*.. We think that these power glitches are causing RAM data to >>change and the PC to change and alter the execution of further code. >>Any suggestions on filtering these spikes? >> >>-- >>andrew >> >>-- >>http://www.piclist.com PIC/SX FAQ & list archive >>View/change your membership options at >>http://mailman.mit.edu/mailman/listinfo/piclist >> >> >> > > > >-- > > >Shawn Wilton (b9 Systems) >http://black9.com > > -- Note: To protect our network, attachments must be sent to attach@engineer.cotse.net . 1-520-850-1673 USA/Canada http://beam.to/azengineer -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist