Power Failure Alarm (CB6116E)

This circuit, suggested by an Electronics World of 1969, keeps a blinking LED for a while when a power outage occurs. Time depends on capacitor C1.

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10 W Amplifier (CB6158E)
This high quality circuit with complementary symmetry was found in an Electronics World of 1966....
Transmit Receive Switch (CB4147E)
This circuit, found in ancient US documentation, allows you to switch the antenna from the...
Two-tone solar buzzer (CB20493E)
This circuit was found in a 1991 publication. The transistor can be a general-purpose type....