Series Fluorescent Lighting....

[xformer]

I have seen a few Schematic Diagrams that deal with Fluorescent lighting that is wired in Series. I am referring to the operation of the fixture in which when one lamp is removed or burned out the other lamp stops working as well. When I look at the schematic I don't see a series connection. Does the word "series" only apply to operational characteristics?

 

[kwired]

I have seen a few Schematic Diagrams that deal with Fluorescent lighting that is wired in Series. I am referring to the operation of the fixture in which when one lamp is removed or burned out the other lamp stops working as well. When I look at the schematic I don't see a series connection. Does the word "series" only apply to operational characteristics?

This was common with most magnetic ballasts designed for multiple lamps, the lamps were not in a direct series as far as connecting external ballast leads, but they were in series with each other as well as components within the ballast, removing one lamp opened the circuit and the other lamp doesn't light in that scenario.

The F96T12 instant start systems were even semi sort of in series with the incoming power IIRC.

It has been long enough that the T8's have taken over I kind of forgot - I used to know better just how these were wired internally in the ballast.

I think most if not all electronic ballasts, directly drive each lamp and there is no series connections between lamps and or ballast components.

 

[xformer]

This was common with most magnetic ballasts designed for multiple lamps, the lamps were not in a direct series as far as connecting external ballast leads, but they were in series with each other as well as components within the ballast, removing one lamp opened the circuit and the other lamp doesn't light in that scenario.

The F96T12 instant start systems were even semi sort of in series with the incoming power IIRC.

It has been long enough that the T8's have taken over I kind of forgot - I used to know better just how these were wired internally in the ballast.

I think most if not all electronic ballasts, directly drive each lamp and there is no series connections between lamps and or ballast components.

know where I can find how these ballasts are wired internally?

 

[AdrianWint]

In days gone by, when magnetic ballasts where common, a series circuit of two short lamps (usually 24 inch 20W) was common here in the UK.

The lamps would be operated from a single choke but had individual starters. Failure of a single lamps doesnt put both out of action (as long as the heater coil in the failed lamp remains intact) since the glow starter still remains conductive & allows the second lamp to continue to burn (its now in series with the two heaters & the glow starter for the other tube as well as the choke)

 

[kwired]

know where I can find how these ballasts are wired internally?

With electronic ballasts dominating the markets I had a hard time finding such information, and I know it used to be kind of easy to find before, but I finally found this document that has some basic internal schematics for several ballast types.