I
ian field
- Jan 1, 1970
- 0
Here's a trick that might interest anyone who enjoys repairing things.
Every year the local cheapo store stocks "bug lanterns" which they don't
roll out until half way through summer because they know the blue
fluorescent tube won't last the distance! The ballast is badly designed -
consisting of a pair of parallel capacitors (1u & 0.56u) in series with a
parallel pair of 100 Ohm 2W resistors (for 240V).
When the lamp fails, the zapper voltage multiplier is still in GWO but a
replacement tube is £5 against £8 for a new lantern. Normally not a good
investment, but in view of the very short tube life something else can be
done.
To avoid the cost of a replacement tube it should be tackled before failure,
the units I have it was found that removing the ballast components left
enough space on the PCB to glue on a board salvaged from a 7W CFL, if one of
the ex ballast capacitors is added to the electrolytic on the CFL board it
will have a very long life and the tube should be good for a couple of years
continuous use. An incidental benefit is energy saving, when I opened the 7W
CFL I found it had tiny TO92 transistors, so the board is obviously not
going to draw as much power as the original ballast resistors which had
burnt the PCB black!
Every year the local cheapo store stocks "bug lanterns" which they don't
roll out until half way through summer because they know the blue
fluorescent tube won't last the distance! The ballast is badly designed -
consisting of a pair of parallel capacitors (1u & 0.56u) in series with a
parallel pair of 100 Ohm 2W resistors (for 240V).
When the lamp fails, the zapper voltage multiplier is still in GWO but a
replacement tube is £5 against £8 for a new lantern. Normally not a good
investment, but in view of the very short tube life something else can be
done.
To avoid the cost of a replacement tube it should be tackled before failure,
the units I have it was found that removing the ballast components left
enough space on the PCB to glue on a board salvaged from a 7W CFL, if one of
the ex ballast capacitors is added to the electrolytic on the CFL board it
will have a very long life and the tube should be good for a couple of years
continuous use. An incidental benefit is energy saving, when I opened the 7W
CFL I found it had tiny TO92 transistors, so the board is obviously not
going to draw as much power as the original ballast resistors which had
burnt the PCB black!