This circuit is from an American documentation from 1975. The circuit uses components of the time which can be replaced by modern equivalents. The coupler is homemade with a lamp and a photocell.
In current sensors such as the INA185 from Texas Instruments, protection against input transients can be...
This circuit consists of a controlled charge to discharge batteries under test. The circuit is...
This high-impedance headphone circuit was found in a 1990s William Sheets. The power is low, but...