Evan
Enlightened
Until recently RayOvac made a 2-6 watt flourescent lantern in the U.S. that I really like. I've bought several and taken a few apart. The circuit inside was really neat, it will run any T5 flourescent you connect to it from F4T5 to F13T5, and the smaller ones in combination.
The circuit seems simple, just 2 TO-92 transistors, a coil, two capacitors, and two resistors. I've traced the circuit and don't know how it does what it does, it seems to be a constant current source for the flourescents and somewhat regulated in that it does not draw more current at 15 volts than at 12. It draws about .1 amp + .21 amp for each 4 watts of series attached tubes. As delivered it takes .73 amp to to run the pair of 6 watt tubes.
If anybody can explain the circuit to me, I'd appreciate it.
Now there were some down sides. It takes 8 D cells and that's a lot of batteries (of course I've modded it to pull from a 12 volt 17 Ah gell cell or AC adapter) and it is dim to start when in the cold.
It seems to have been beaten out by a Coleman lantern that is made in China and looks much the same, except the Coleman takes 1.2 Amps to run the same 2 tubes at what appears to be about the same brightness -- that's a lot more than .73! The Coleman circuit is not nearly so simple and cool. It seems to just pull current and blast it out to the tubes without any regulation. The Coleman shares all the same down sides -- 8 batteries and flourescent tubes that are a little slow on the uptake in the cold -- yet it beat out what I concider a really superior lantern.
The market just doesn't seem to appreciate the hidden beauty of fine and elegant circuitry.
The circuit seems simple, just 2 TO-92 transistors, a coil, two capacitors, and two resistors. I've traced the circuit and don't know how it does what it does, it seems to be a constant current source for the flourescents and somewhat regulated in that it does not draw more current at 15 volts than at 12. It draws about .1 amp + .21 amp for each 4 watts of series attached tubes. As delivered it takes .73 amp to to run the pair of 6 watt tubes.
If anybody can explain the circuit to me, I'd appreciate it.
Now there were some down sides. It takes 8 D cells and that's a lot of batteries (of course I've modded it to pull from a 12 volt 17 Ah gell cell or AC adapter) and it is dim to start when in the cold.
It seems to have been beaten out by a Coleman lantern that is made in China and looks much the same, except the Coleman takes 1.2 Amps to run the same 2 tubes at what appears to be about the same brightness -- that's a lot more than .73! The Coleman circuit is not nearly so simple and cool. It seems to just pull current and blast it out to the tubes without any regulation. The Coleman shares all the same down sides -- 8 batteries and flourescent tubes that are a little slow on the uptake in the cold -- yet it beat out what I concider a really superior lantern.
The market just doesn't seem to appreciate the hidden beauty of fine and elegant circuitry.
