I am always on the lookout for electronic circuits in discarded toys that are adaptable to my railroad, and I found one that is mysterious to me. It's likely you have seen a rubber toy meant to be thrown down so it illuminates. I have taken two such toys apart to see how they work and I do not understand it, so I am asking the electronics wizards that lurk here what their thoughts are.
The circuit contains two LEDs and both of them blink rapidly. The LEDs look like the flashing type. Both are 3mm LEDs. One is red and the other is blue, so the light show is dramatic.
The battery pack contains three LR1130 Button Cells in series. When the circuit is subjected to an impact, a small cantilevered spring momentarily connects the batteries to the circuit. After the spring rebounds to its normal OFF position, the LEDs continue to flash. How is this possible?
Here's another clue. If I remove the batteries while the LEDs are flashing, the LEDs go OFF.
The duration of the flashing is 20 seconds. The LEDs flash too quickly to determine if they flash together, or they alternating flashing in sync, or each flashes randomly.
The printed circuit board (PCB) has blob of white stuff on it that looks like white ceramic material, and its circuit symbols is HJ.
The single layer PCB is 0.75" in diameter and besides the batteries, battery holder, LEDs, white blob and spring, there are no other components.
What is you opinion as to how this circuit keeps on flashing when the spring rebounds to the OFF position?
