The circuit shown in the figure below is from the 1993 Linear Technology Applications. The operational ones used are uncommon and the use of equivalents can be analyzed.
This circuit was obtained from a 1978 Practical Wireless. It causes an LED to flash at a frequency that...
This metal detector was found in a French magazine Radio Plans from 1977. The phone can be a...
This power supply may have 5, 6, 9 or 12 V outputs depending on the 78XX and 79XX series...