Found in an April 1977 Radio Electronics issue, this circuit uses the well-known XR2206. The C1 values for the various frequency bands are given next to the diagram.
This 100-second timer was found in a 2000 Poptronics. The magazine no longer exists, but the...
This circuit uses a photocell as sensor and a sensitive relay according the power supply voltage....
USB58xx and USB59xx Devices Integrate a 2:1 Multiplexer to Support Reversible Connection of USB...