There are two types of cells within the heart: the cardiomyocytes and the cardiac pacemaker cells. Cardiomyocytes make up the atria (the chambers in which blood enters the heart) and the ventricles (the chambers where blood is collected and pumped out of the heart).These cells must be able to shorten and lengthen their fibers and the fibers must be flexible enough to stretch.ardiomyocytes make up the atria (the chambers in which blood enters the heart) and the ventricles (the chambers where blood is collected and pumped out of the heart). These cells must be able to shorten and lengthen their fibers and the fibers must be flexible enough to stretch.
â¢ A ballast-compatible LED tube light will not work without a working ballast. The life of a ballast is limited. Any good LED. tube light will outlive an electronic ballast. A ballast-compatible LED tube light will require regular replacements for as. long as the tube light lasts. When the ballast fails, a new ballast will need to be purchased and installed to keep the. ballast-compatible tubes working. Multiply this by hundreds of fixtures throughout a facility, and the incurred cost.
  The amperage is on the label of the ballast. When you connect the ballast to power you will see it along with the voltage and pf of the ballast. F40T12 twin 8 foot tubes, ballast usually draws about .75 amps. The amperage is on the label of the ballast. When you connect the ballast to power you will see it along with the voltage and pf of the ballast. F40T12 twin 8 foot tubes, ballast usually draws about .75 amps.