Grounding test (CB10092E)

This simple circuit for a common 110 V power grid was found in a 1980s American documentation. The circuit uses neon lamps as indicators.

| Clique na imagem para ampliar |

Darkroom photometer (CB8344E)
This circuit is from the time when photos were revealed in darkrooms. We found it in a 1968...
High gain audio amplifier (CB8938E)
This high-gain circuit was found in an American publication from the 1990s. The circuit can use...
1.5 to 10 V inverter (CB20462E)
This circuit provides an output of 5 to 10 V at its output from inputs of 1.5 to 4.5 V. The output...