ISD1016 Voice Recorder (CB25448E)

This 16-second voice recording circuit was featured in a telephone answering machine circuit in the March 1992 issue of Radio Electronics magazine.

| Clique na imagem para ampliar |

1 to 999 Minutes Programmable Timer (CB4436E)
We found this interesting timer circuit or CMOS timer in a 1988 publication. The circuit is still...
Continuity Test (CB22130E)
This circuit can be powered by 2 or 3 small batteries. The resistor can have values between 220...
Beacon transmitter (CB9382E)
Found in a magazine 73 for radio amateurs, this circuit operates in the 144 MHz band, at a...