This circuit switches on an external load after a certain interval given by the capacitor. The circuit is from a documentation from the 80s. The load depends on the relay used.
This circuit is from an article in Radio Electronics magazine from August 1972. The circuit is...
This 1kHz rejector filter can be modified to operate at other frequencies. Operational can be just...
This circuit is from American documentation from the 90s. The transistor is general-purpose and...