[Eric Wasatonic] had a box of SWB2433 transistors that he had very little information about. In order to discover their properties, he fired up his curve tracer to compare these transistors with more ...

This circuit generates a two-tone effect very much alike the cuckoo song. It can be used for door-bells or other purposes thanks to a built-in audio amplifier and loudspeaker. Agreeable, very close ...

[Debraj] needed a simple signal generator for a project he was working on, but didn’t have one handy. He found that the easiest and cheapest way to get clean, reliable signaling was by using something ...

This circuit generates a dual-tone bells ringing similar to most door-bell units. It can be used in many applications other than door-bell. In the Notes below several options will be given in order to ...