Found in a 1968 Novel Electronics Circuit, this circuit compares two light intensities using common LDRs as sensors. Transistors can be modern PNP equivalents.
This is a simple configuration for a low-pass filter using a 741 operational-amplifier. Other...
This circuit is from an English book from the 1980s. Transistors can be general-purpose types of...
This circuit is from a technical documentation from Motorola from the 70s, and for this reason it is...