This circuit, which can be seen elsewhere on this website, was obtained from a 90’s English documentation. The circuit drives a small speaker, but for greater volume an external amplifier must be used.
The integrated circuit used is a dual 555 CMOS. The circuit is from an English documentation and...
A 3-input OR gate can be made with an LM3900 amplifier, as shown in the figure. The purpose of the...
We found this conventional power source with a regulating transistor in a 2002 documentation. The...