This circuit was found in the August 1993 Electronics Now magazine. It is for telephones used on common old-style analog lines.
This metal detector circuit uses an AM radio as an indicator. The radio is placed off-station and tuned...
This circuit trips when the input voltage exceeds 30 V. Its base is a DIAC and it can be used to...
This simple measuring bridge allows the capacitance m of some pF to microfarads to be measured...