Switchable Ballast?

Is the only difference between a MH and a HPS ballast that the HPS sodium ballast has an igniter? Thanks in advance for any help with this.

 

MH ballast run metal halide lamps, and HPS ballasts run high pressure sodium lamps. MH's give off mostly the blue spectrum or light, and HPS's give off mostly the red spectrum of light.

 

Yeah, I already know everything you just told me. I'm simply asking about the ballast itself. I have a ballast for my MH lamp that came un-assembled. I'd like to use a HPS lamp for budding and I want to know if I can simply add an igniter to the set-up to create a ballast for the HPS lamp. It's my understanding that this is the only difference in the two types of ballasts but I'm not sure.

 

Hope this helps:

http://www.venturelighting.com/BallastHTMLDocuments/wiring_diagrams-Add.html

 

I think it does. Thanks