Motion Sensor numitron clock

Thanks for pointing out the problem and getting discussion started. I have one question: on the clock pictured, are you using a "date slots" effect?

Thanks. I was just wondering because in my testing I think I'm seeing two separate issues: overall low voltage causing random false triggers, and high voltage spikes causing false triggers every time the slots effect runs. Apparently your good power supply can cope with both.

The microwave sensor is very, very sensitive to voltage fluctuations.

I am using a PIR detector at the moment, and have ordered some prototype boards with a Zener based 4V7 regulator on it.

The PIRs work fine, the microwaves are WIP at the moment... Sorry.

The only other thing I have found is that the quality of the 5V supply is important. I have a couple of clocks that work perfectly with the microwave, and some that don't. The problem appears to move with the supply rather than the clock...