This circuit, obtained from a 1965 magazine, can still be assembled using some modern equivalent components. The transistors may be BC558 and the transformer is obtained from a disused transistor radio.
The amount of light emitted by na LED is given by the intensity of the current flowing across it....
This circuit was obtained from an English magazine from 1980, but as it uses components that can...
November 2016 - Maxim's MAX30003, an Analog Front End (AFE) for biopotentials with clinical grade...