This circuit was found in an American documentation of the 90s. Optical resources with the LDR as a lens can help in obtaining directivity and sensitivity.
We found this circuit in a 1973 publication. The circuit lets frequencies below 480 kHz pass...
This power supply was originally indicated for work with electroplating. The transformer is 2 A or...
This simple circuit serves to identify the terminals of a PNP transistor. For NPN transistors, just invert...