This circuit is from Motorola documentation, but can be implemented with virtually any phototransistor and any general-purpose transistor. The supply voltage can also be changed.
This circuit, which uses only common transistors, was obtained from a 1988 publication, but can be...
The integrated circuit used in this filter is not very common today, but the configuration can be implemented...
Published in Radio Electronics magazine in March 1963, this circuit uses 4 transistors of the...