GrowFAQ:

What is a switchable ballast?

  Added by: MedMan  Last edited by: MedMan  Viewed: 827 times   Rated by 5 users: 4.67/10
A switchable ballast allows you to run a standard halide or sodium bulb from one ballast, you just insert the appropriate lamp and set the switch to the correct operating setting.

This type of ballast enables growers to bypass costly conversion lamps and maintain the higher light output from non conversion bulbs.
  Last modified: 18:35 - Jun 27, 2001  

faq:1041 "What is a switchable ballast?"