This circuit was obtained from an 80's Radio Electronics. The circuit decodes “scrambled” or sinusoidal encoded signals by providing an audio signal at the output.
We found this circuit of a transistor siren in a recent English publication. All components are still...
Other series amplifiers such as the MC3301, MC3401 and LM2900 can be used on this circuit. We found...
We find this efficient emergency lighting system in a 1987 publication. The circuit keeps a...