Hi,

my problem is as follows:

My Cygnal µC controls a relay that switches 230V mains power. There is no load connected to the relay. When switching I get big fast spikes on the 3V supply voltage and all other signals. This leads to a hanging µC and watchdog reset.
Filtering of the supply and signals did not solve the problem.
Can anyone explane, why this happens even without load?
Are there any links to relevant sites, where I can get more information about this?

Best regards,
Carsten