Measuring the speed of a rotating object is a common requirement. Knowing the speed of table and ceiling fans, as well as kitchen appliances such as mixers ...

The experiment is for switching an acoustic sounder as a rain alarm after a predetermine time. It may, however, be tinkered for a number of other applications. Needless to say, this is a simple ...

I know how to solder, but I do not always want to solder, and I think there are a lot of folks like me. Even if the act itself can be done (and undone, and redone), the friction of hauling out the ...

A few weeks ago, I installed an automatic water heater switch to my bathroom, but it was a crude device. What I really want to do is design a universal heater driver. That basic idea can be adapted to ...