300 to 3,000 Hz Speech Filter (CB6543E)

Found on an 80's Radio Electronics, this two-section circuit is designed to pass the frequency range of the human voice.

| Clique na imagem para ampliar |

Presence Simulator (CB18682E)
This circuit produces sequential outputs for the activation of several appliances in a residence, thus...
Simple Siren (CB240E)
Pressing and releasing S, the capacitor C1 charges and discharge slowly through the oscillator...
Wien Bridge Oscillator (CB4922E)
This circuit uses an operational that is not currently common. We found it in an old American...