This circuit uses the LM2931 which is not a common component today. What it does is to activate a lamp causing it to blink at a frequency determined by the capacitor.
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The configuration shown was found in an old Poptronics but can be easily assembled using a common...
This circuit is from an old American publication. The indicated transistor is oversized as the 15 V...
Found in a 90’s Radio Electronics magazine, this circuit uses a component from the time, difficult...