This circuit is from 1980s documentation. The maximum operating frequency is 3.5 MHz. The current of the LED can be from 0 to 100 mA. The integrated circuits used are from that time.
This circuit was obtained in a 1975 documentation. The maximum frequency depends on the diodes and the...
In the figure we have the basic configuration of an operational amplifier for AC signals using the...
This traditional signal injector from a 1970s publication uses germanium transistors. We can mount it...