We found this circuit in a 1986 documentation. It uses only LEDs, batteries, resistors and the power supply which can consist of 4 batteries or a 9V battery. The basic circuit uses two-color LEDs.
Found in a 1964 magazine, this is a small headphone amplifier from 500 ohms to 10 k ohms (magnetic...
In the figure we have the way to use an operational amplifier on a higher voltage source than it...
In the figure we have the receiver of a sequential remote control operating at a frequency in the range of...