Logic level indicator 7400 (CB22407E)

In the figure we have a simple logic level indicator for TTL circuits or powered by 5 V.

Two-color indicator (CB7824E)
This two-color LED indicator was found in a Popular Electronics from the 90's. The transistor...
Frequency divider for 10 MHz standard (CB21041E)
This circuit was found in a Radio Electronics from the 90's. It provides lower frequency signals from...
Monostable with the 4098 2 (CB11446E)
This monostable circuit uses one of the two flip-flops available on the CMOS 4098 integrated...