This circuit was found in the July 1988 issue of Radio Electronics magazine. It makes use of an operational transconductance amplifier (OTA) still in use today.
This shield was found in a 90’s Popular Electronics. The circuit can be implemented with modern...
As in the previous case (CB5045E), we have in the circuit of the figure the use of the polarized...
This TTL siren is formed by two oscillators using each two Gates of a 7400. Frequency or the...