Equipment ‘ON’ Counter for 68 Years Max.

Have you ever wondered how long a piece of electric equipment has been switched on and consuming AC power? The simple circuitry shown here counts the seconds of the ON time periods and keeps the total accumulated time in the EEPROM inside the ATtiny13 microcontroller. Just read the EEPROM with the help of an appropriate ISP programmer or the dedicated readout circuit and you will know how “old” the equipment really is!