I have an Atmega328p based node with RFM69HW radio, controlling a relay. Power is supplied using a cheap 220V to 5V Chinese power supply (see photo). A 30W led bulb is connected through the relay to mains power.
The problem is, when I run test, which turns on and off the relay once per 5 second, sometimes (once per 5-10) the system just reloads. I checked every part with an oscilloscope and found that the power supply has voltage drop to near zero, which causes the system restart. Checked with different power supply, everything works perfect. Also, without the bulb it works.
Can anything be done to fix the problem?