This rapid response amplifier uses an integrated one that is not common today but can be implemented with modern equivalents. The circuit is from an 80's manufacturer documentation.
The MC15555 of this circuit is the old version of the common 555. What this circuit does is...
We find this circuit in an American 1980s documentation. The circuit can still be assembled...
This circuit triggers an LM380 oscillator, producing an audio tone with light falling on the LDR....