Musical doorbell (CB9210E)

This musical doorbell was found in a Popular Electronics from the 90s. The U4 melody generator integrated circuit is uncommon today.

| Clique na imagem para ampliar |

Divide-by-2 Counter - 4018 (CB164E)
One flip-flop of the 4018 can be used as a frequency divider or counter as shown here. Frequency...
Display drive 4033 (CB7554E)
We found in this American documentation this circuit for activating common cathode displays. In it we...
SST LLE Series Liquid Level Sensor Switches
SST LLE Series Liquid Level Sensor Switches Available through Mouser Electronics, these solid...