This circuit has a maximum frequency of 10 kHz and a linearity better than 0.01%. The circuit is from an 80's documentation making use of integrated of the time.
This circuit was obtained from an old American documentation, and practically any general-purpose transistor...
This circuit is intended for monitoring an environment. It fires a relay with a sound, but only if...
This circuit is from an old documentation, but perfectly current. In place of the battery, 2 or 4...