This circuit, to control air conditioning systems, was found in July 1984 Radio Electronics magazine. The circuit is for old types of the time that did not have microcontroller control.
We found this simple alarm circuit in a 1981 documentation. As we can see, it is a car alarm...
This small regulator was found in a Motorola 1968’s documentation. It is a current regulator using...
This low-pass filter with 741 op and symmetrical source was found in the August 1993 issue of...