energy monitor

Many electrical appliances in the home have become so automated that it is no longer necessary to switch them on and off manually. Unfortunately, this also means that you have no idea how many units of power (KWh) they are consuming. To find out how long the central heating system has been reducing the level of oil in the tank (black gold nowadays) or for how long the compressor of the fridge has been running, an "operational hours" counter would be ideal. The simple energy meter described here totals the individual operation times up to twelve hours. The actual "meter" is a car clock which runs on 6 or 12 volts. Which of the circuits is used (figures 1 and 2) depends on the operating voltage of the clock. The complete circuit is connected in parallel to the device to be monitored and will only work when the device is operating. As the maximum operating time of the clock is 12 hours it should be "read" regularly and the reading logged. The clock can then be reset. The majority of ...