Alarm transmitter (CB21874E)

This circuit was found in an Australian publication from 1991. The circuit emits a tone as well as the picked up sound when triggered.

| Clique na imagem para ampliar |

Small Stethoscope (CB12617E)
This circuit, from an old publication from the 1970s, can be made with silicon transistors like...
Universal Motor Control (CB1311E)
We find this circuit in documentation from the 1980s. The triac and diac are of conventional types...
Pulse Converter with Unijunction (CB18535E)
The purpose of this circuit is to convert a short-lived pulse into a negative rectangular pulse. The...