This circuit was found in ancient American documentation. It makes use of the operational amplifiers of the time, but it can be implemented with modern equivalents.
The component used in this circuit is uncommon today, as the circuit was obtained from Motorola's Linear...
This simulated circuit on the NI Multisim transmits modulated infrared signals with the audio...
This voltage sensor limits the discharge of a Nicad battery. We found it in an American...