By hooking together two counters, you can obtain a sequential count from 1 to 19. The circuit uses IC 4, a CD4069 inverter, as a reset-delay enable to cause a few milliseconds of delay before each ...

Inside the box, a 555 in astable mode drives a decade counter, which outputs the numbers 0-9 sequentially on the Nixie via beefy transistors. While the G-M tube waits for muons, the numbers just ...

Each of the six digits has its own binary-coded decimal chip and array of discrete resistors. Timekeeping is handled by six decade counters, two divider chips, one AND gate chip, and one OR gate chip.