All-Electronic Counter/Timer for Current Meters
CUP and propeller type current meters 
originally required an operator 
to count contact closure noise using earphones. 
Commercial counters then became 
available using an electromechanical 
readout. These counters have problems 
because either the points in the 
current meter head carry the current to 
drive the counter which results in contact 
burning, or there is an intermediate 
relay between the points and the 
counter which introduces another 
source of possible mechanical failure. 
The timebase on these units is usually a 
stopwatch which must be controlled by 
the operator and has no direct electrical 
control upon the operation of the 
counter. The watches are delicate 
mechanical devices subject to wear and 
breakage.