We all know the shape by heart
A simple 555 timer that blinks the test result strip. The idea for it came in a time when nobody really was certain if it is safe to meet up in groups and conventions again. There was a constant uncertainty, tbh - there still is these days. So why not Have a 555 timer blink to that Schroedinger uncertainty?
| designator | value |
|---|---|
| R1, R4 | 100 Ohm |
| R2 | 390k Ohm |
| R3 | 150 Ohm |
| C1 | 1uF |
| D1, D2 | RED LED (solder upside down!) |
| U1 | LMC555 timer 3V capable |
| J1 | IDC header |