best lights for growing in a 4ftx4ftx6ft closet
- Thread starter growjahherb
- Start date
gohydro
Well-Known Member
Here's a quote from a mfg....enough said. Go electronic/switchable.
Different ballasts meet the needs of different setups. For example, mercury and metal halide lamps have an additional electrode and require open circuit voltage (O.C.V.). Essentially, this means they need about double the lamp voltage to start. Compare those with high pressure sodium lamps, which have no starting electrodes but nevertheless require both an O.C.V. of two times the lamp voltage but also a high voltage starting pulse from an igniter. Low Pressure Sodium lamps, also called LPS lights, need about three to seven times the lamp voltage due to a lack of both starting electrode and igniter. Some magnetic ballasts modulate electrical current at a relatively low cycle rate, which occasionally can cause a noticeable flicker. These ballasts may also vibrate at a low frequency, causing slightly audible noise.
Different ballasts meet the needs of different setups. For example, mercury and metal halide lamps have an additional electrode and require open circuit voltage (O.C.V.). Essentially, this means they need about double the lamp voltage to start. Compare those with high pressure sodium lamps, which have no starting electrodes but nevertheless require both an O.C.V. of two times the lamp voltage but also a high voltage starting pulse from an igniter. Low Pressure Sodium lamps, also called LPS lights, need about three to seven times the lamp voltage due to a lack of both starting electrode and igniter. Some magnetic ballasts modulate electrical current at a relatively low cycle rate, which occasionally can cause a noticeable flicker. These ballasts may also vibrate at a low frequency, causing slightly audible noise.