Parallel electric circuits. Animation showing the principle of electric circuits connected in parallel, and the measurement of electric current and voltage. The animation starts with a schematic view of an electric circuit, showing the power source (electric cell, or battery) at top. At lower right is an ammeter ('A' symbol), used to measure electric current in amperes (amps). At lower left, connected across the component drawing electric current, is a voltmeter ('V' symbol), used to measure the potential difference in volts. The component drawing power in this case is an electric lamp ('cross' symbol). The start of the animation shows electric current (blue dots) flowing around the circuit, causing the electric lamp to light up. An initial voltage reading is shown as 2 volts. The addition of two further light bulbs in parallel to the existing one does not change the voltage. The second half of the animation shows the electric current measurements. As more light bulbs are added, more current is drawn from the battery. Each light bulb draws 0.30 amps. The ammeters either side of the battery show the total current drawn increasing from 0.30 to 0.60 and then 0.90 amps. This is for a single 2-volt battery. The end of the animation shows the measurements with three 2-volt batteries with a total voltage of 6 volts and a total current of 2.7 amps (with each lamp drawing 0.90 amps). The basic principle is that the voltage is the same across each device connected in parallel, with the total electric current being the sum of the electric currents through the individual components. i.e. For parallel circuits, the current increases but the voltage stays the same. For the principles of circuits connected in series, see clip K005/6745.