Found in American documentation from the 1980s, this circuit makes use of components of the time, which are uncommon today. The circuit detects the approach using a sensor formed by metal plates.
Found in a 1968 American documentation, this circuit generates sawtooth signals whose rise and...
This TTL siren is formed by two oscillators using each two Gates of a 7400. Frequency or the...
Although it is a circuit from the 80s, it can still be easily implemented today because the...