Editing Clock (section)

===Counter chain===

This counts the pulses and adds them up to get traditional time units of seconds, minutes, hours, etc. It usually has a provision for ''setting'' the clock by manually entering the correct time into the counter.
* In mechanical clocks this is done mechanically by a [[gear train]], known as the [[wheel train (horology)|wheel train]]. The gear train scales the rotation speed to give a shaft rotating once per hour to which the [[minute hand]] of the clock is attached, a shaft rotating once per 12 hours to which the [[hour hand]] of the clock is attached, and in some clocks a shaft rotating once per minute, to which the [[clock face|second hand]] is attached.  The gear train also has a second function; to transmit mechanical power from the power source to run the oscillator. There is a friction coupling called the 'cannon pinion' between the gears driving the hands and the rest of the clock, allowing the hands to be turned to set the time.<ref>Milham, 1945, p. 113</ref>
* In digital clocks a series of [[integrated circuit]] [[counter (digital)|counters]] or dividers add the pulses up [[Digital data|digitally]], using [[binary numeral system|binary]] logic. Often pushbuttons on the case allow the hour and minute counters to be incremented and decremented to set the time.