This window comparator circuit was found in a Popular Electronics from the 90s. The circuit has a multiple adjustment input network to determine the operating ranges.
It is a simple blinker that simulates the action of an alarm when installed on the dashboard of a...
The circuit is from a 1978 publication and the transistor may be the BC558. The transformer is...
This simple unregulated circuit was found in a Radio Electronics from June 1964. Note that the...