I built a circuit that pulses a 50-ohm electromagnet when a 'trigger' magnet passes over a hall-effect sensor. This circuit swings a pendulum and simultaneously plays an audio clip as long as the 555 timer output is high.
This worked perfectly on a breadboard, but when I mounted all components on a small soldered circuit board, the audio module now resets (starts from the beginning, indicating a loss of power) each time the coil is triggered.
I used (4) AA batteries so I could tap the 3rd cell to provide ~5v to the audio module and avoid using a 7805 or similar.
I have an electronic engineering background, but not enough experience to know what may be causing the problem or what modifications are needed. I also unfortunately do not have an oscilloscope.
I am very interested to understand what may be causing the problem and very much appreciate any help the forum can provide.
Many thanks in advance!