Found in Texas Instruments documentation from the 1980s, this circuit applies to digital signal transmission with FSK modulation. The circuit is slow, as it uses period components.
This circuit triggers the LED when the monitored battery voltage drops below 9 V for 12 V...
Found in a Linear Technology 80s integrated circuit manual this circuit has its gain controlled from...
This very low consumption circuit can be powered by a solar cell. The time indication is given by a...