Siren in a box (CB7093E)

Found in Elementary Electronics from 1970, this circuit is a toy for generating different types of sound effects. The circuit is battery powered.

| Clique na imagem para ampliar |

1 W LM386 Amplifier (CB17022E)
This circuit has appeared several times on this site in different applications. This is from 1997...
Digital Multimeter Thermometer (CB17031E)
This circuit allows you to use a digital multimeter as a thermometer. The sensor is mounted in a...
Alarm 555 (CB14942E)
This alarm circuit was found in a 1989 Poptronics, but all the components used are common, as the...