A simple and convenient way to interface 2 relays for switching application in your project. This relay driver boosts the input impedance with a regular BC547 NPN transistor (or equivalent). Very ...
I recently helped a friend install a “smart” Ecobee 3 thermostat in the second floor of his home, see “HVAC Upgrade Shows Interconnect Complexity of These “Simple” Systems”. He was so pleased with its ...