Homebrew PCBs

Hi all,

After many hard-fought battles with different inkjet printers, I've decided to try using the UV method  with negative photoresist.  

I'm wondering if anyone knows enough about the operation of UV ballasts to offer advice:
I have an old lamp designed to take short, straight fluorescent tunes with ballasts on each end (4 pins in total).  I'm wondering if that lamp will be compatible with this U-shaped bug killing bulb: http://www.homedepot.ca/product/ultraviolet-replacement-bulb-for-bk-80acan-insect-killer/945544 . Of course I'll make sure it fits, but I'm wondering if it's electronically compatible.  

From  the fluorescent-light Wikipedia page, I'm having a hard time figuring out if the operation on both ends is symmetric.

On Wed, Nov 2, 2011 at 5:15 PM, b3nzilla <b3nzilla@...> wrote:

> **
>
>
> Hi all,
>
> After many hard-fought battles with different inkjet printers, I've
> decided to try using the UV method with negative photoresist.
>
> I'm wondering if anyone knows enough about the operation of UV ballasts to
> offer advice:
> I have an old lamp designed to take short, straight fluorescent tunes with
> ballasts on each end (4 pins in total). I'm wondering if that lamp will be
> compatible with this U-shaped bug killing bulb:
> http://www.homedepot.ca/product/ultraviolet-replacement-bulb-for-bk-80acan-insect-killer/945544. Of course I'll make sure it fits, but I'm wondering if it's
> electronically compatible.
>

Yes, it should be fine providing you get the filaments connected correctly
(i.e. you need to connect one filament to one side, and vice-versa).  You
can check with an ohm-meter for a filament connection to determine a pair
of pins to connect to one side and then use the other pair for the other
side.  Sorry if I'm not explaining this clearly but you need to make sure
that you don't cross-connect the pins of the ballast since it could damage
it.  The only other thing to check for is the wattage of the ballast and
the bulb you're using.  Generally you can use a larger-sized (Within
25-50%) ballast for a smaller tube but not the other way around since
ballasts tend to run hot anyway.


>
> From the fluorescent-light Wikipedia page, I'm having a hard time figuring
> out if the operation on both ends is symmetric.
>
> Yes, operation is symmetric since the tube is fed on AC and has no
polarity.  Each tube end has an identical heater filament to connect to one
half of the ballast.  If your existing ballast won't work for you there's
always the possibility of buying a proper ballast (And if not integrated,
an igniter) and soldering directly to the tube instead of fooling around
with flaky connectors.  You're very unlikely use the light enough to need
to replace it anyway (I've had the same lights for years and only replaced
them when I accidentally broke them).  I would recommend using at least two
of the U-shaped bulbs to get enough light to provide an even light
distribution at an appropriate distance.


Regards,
Larry

> __.__Y
>


[Non-text portions of this message have been removed]

Just to confirm -- the U-shaped bulb I'm using has only one set of pins. Do
I use two pins on the lamp that are or that are not connected?


Thanks!



On 2011-11-03, at 12:06 AM, Larry Battraw <lbattraw@...> wrote:



On Wed, Nov 2, 2011 at 5:15 PM, b3nzilla <b3nzilla@...> wrote:

> **
>
>
> Hi all,
>
> After many hard-fought battles with different inkjet printers, I've
> decided to try using the UV method with negative photoresist.
>
> I'm wondering if anyone knows enough about the operation of UV ballasts to
> offer advice:
> I have an old lamp designed to take short, straight fluorescent tunes with
> ballasts on each end (4 pins in total). I'm wondering if that lamp will be
> compatible with this U-shaped bug killing bulb:
>
http://www.homedepot.ca/product/ultraviolet-replacement-bulb-for-bk-80acan-insect-killer/945544
. Of course I'll make sure it fits, but I'm wondering if it's
> electronically compatible.
>

Yes, it should be fine providing you get the filaments connected correctly
(i.e. you need to connect one filament to one side, and vice-versa). You
can check with an ohm-meter for a filament connection to determine a pair
of pins to connect to one side and then use the other pair for the other
side. Sorry if I'm not explaining this clearly but you need to make sure
that you don't cross-connect the pins of the ballast since it could damage
it. The only other thing to check for is the wattage of the ballast and
the bulb you're using. Generally you can use a larger-sized (Within
25-50%) ballast for a smaller tube but not the other way around since
ballasts tend to run hot anyway.

>
> From the fluorescent-light Wikipedia page, I'm having a hard time figuring
> out if the operation on both ends is symmetric.
>
> Yes, operation is symmetric since the tube is fed on AC and has no
polarity. Each tube end has an identical heater filament to connect to one
half of the ballast. If your existing ballast won't work for you there's
always the possibility of buying a proper ballast (And if not integrated,
an igniter) and soldering directly to the tube instead of fooling around
with flaky connectors. You're very unlikely use the light enough to need
to replace it anyway (I've had the same lights for years and only replaced
them when I accidentally broke them). I would recommend using at least two
of the U-shaped bulbs to get enough light to provide an even light
distribution at an appropriate distance.

Regards,
Larry

> __.__Y
>

[Non-text portions of this message have been removed]

 


[Non-text portions of this message have been removed]

With only two pins it is going to be of the cold start type using high
voltage instead of heated filaments.

I expect it won't start with a regular ballast.

ST

On Thu, Nov 3, 2011 at 5:05 PM, Benjamin Blumer <b3nzilla@gmail.com> wrote:
> Just to confirm -- the U-shaped bulb I'm using has only one set of pins. Do
> I use two pins on the lamp that are or that are not connected?
>
>
> Thanks!
>
>
>
> On 2011-11-03, at 12:06 AM, Larry Battraw <lbattraw@...> wrote:
>
>
>
> On Wed, Nov 2, 2011 at 5:15 PM, b3nzilla <b3nzilla@...> wrote:
>
>> **
>>
>>
>> Hi all,
>>
>> After many hard-fought battles with different inkjet printers, I've
>> decided to try using the UV method with negative photoresist.
>>
>> I'm wondering if anyone knows enough about the operation of UV ballasts to
>> offer advice:
>> I have an old lamp designed to take short, straight fluorescent tunes with
>> ballasts on each end (4 pins in total). I'm wondering if that lamp will be
>> compatible with this U-shaped bug killing bulb:
>>
> http://www.homedepot.ca/product/ultraviolet-replacement-bulb-for-bk-80acan-insect-killer/945544
> . Of course I'll make sure it fits, but I'm wondering if it's
>> electronically compatible.
>>
>
> Yes, it should be fine providing you get the filaments connected correctly
> (i.e. you need to connect one filament to one side, and vice-versa). You
> can check with an ohm-meter for a filament connection to determine a pair
> of pins to connect to one side and then use the other pair for the other
> side. Sorry if I'm not explaining this clearly but you need to make sure
> that you don't cross-connect the pins of the ballast since it could damage
> it. The only other thing to check for is the wattage of the ballast and
> the bulb you're using. Generally you can use a larger-sized (Within
> 25-50%) ballast for a smaller tube but not the other way around since
> ballasts tend to run hot anyway.
>
>>
>> From the fluorescent-light Wikipedia page, I'm having a hard time figuring
>> out if the operation on both ends is symmetric.
>>
>> Yes, operation is symmetric since the tube is fed on AC and has no
> polarity. Each tube end has an identical heater filament to connect to one
> half of the ballast. If your existing ballast won't work for you there's
> always the possibility of buying a proper ballast (And if not integrated,
> an igniter) and soldering directly to the tube instead of fooling around
> with flaky connectors. You're very unlikely use the light enough to need
> to replace it anyway (I've had the same lights for years and only replaced
> them when I accidentally broke them). I would recommend using at least two
> of the U-shaped bulbs to get enough light to provide an even light
> distribution at an appropriate distance.
>
> Regards,
> Larry
>
>> __.__Y
>>
>
> [Non-text portions of this message have been removed]
>
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>
>

I have found the small 2 pin U lamps are actually 4 pin internally with filaments.  Inside the base one pin from each end of the lamp are connected together through a capacitor.

I suspect one could remove the cap and use a normal 4 wire ba1last, a series inductor with click starter or even a push button switch starter with series inductor. Got to be a billion ways to make these things work.


Here is how the two pin (with cap bulbs work) CFL bulbs work.  To start the bulb the electronic balast puts out a frequency that resonates with the series cap and its output inductor. This allows current to flow through the bulbs filaments and heats the mercury vapor. Also because of the resonance there is a fairly high voltage across the cap ( big phase shift here). The high voltage eventually causes an arc to form in the tube drastically lowering the tube's internal resistance and the voltage across it from well over 100V to to less that 60V depending on temp.  Once the arc if formed the tube's resistance is very low compared to the caps reactance and the cap is effectively out of the circuit.  Then it's just the electronic chopper driving the tube through the output inductor to limit the current.  The CFL's circuit is very crude but effective.

Ever wonder why you don't get 25 years out of the CFL's -- they are built so cheaply without any line transient protection. One overvoltage spike and it's toast.

You can actually buy a low cost CFL, hack the board out of he CFL and use it on your UV light.  Just remember chopped 168V non isolated power will knock you off your chair.

Craig

The CFL act just similar to a flashlamp. They have negative resistance 
curves - initial high impedance and then low impedance once the arc is 
drawn. Takes me back a couple of decades to my flashlamp days of 20kW+.

Derek Koonce
DDK Interactive Consulting Services

On 11/4/2011 8:58 AM, designer_craig wrote:
>
> I have found the small 2 pin U lamps are actually 4 pin internally 
> with filaments. Inside the base one pin from each end of the lamp are 
> connected together through a capacitor.
>
> I suspect one could remove the cap and use a normal 4 wire ba1last, a 
> series inductor with click starter or even a push button switch 
> starter with series inductor. Got to be a billion ways to make these 
> things work.
>
> Here is how the two pin (with cap bulbs work) CFL bulbs work. To start 
> the bulb the electronic balast puts out a frequency that resonates 
> with the series cap and its output inductor. This allows current to 
> flow through the bulbs filaments and heats the mercury vapor. Also 
> because of the resonance there is a fairly high voltage across the cap 
> ( big phase shift here). The high voltage eventually causes an arc to 
> form in the tube drastically lowering the tube's internal resistance 
> and the voltage across it from well over 100V to to less that 60V 
> depending on temp. Once the arc if formed the tube's resistance is 
> very low compared to the caps reactance and the cap is effectively out 
> of the circuit. Then it's just the electronic chopper driving the tube 
> through the output inductor to limit the current. The CFL's circuit is 
> very crude but effective.
>
> Ever wonder why you don't get 25 years out of the CFL's -- they are 
> built so cheaply without any line transient protection. One 
> overvoltage spike and it's toast.
>
> You can actually buy a low cost CFL, hack the board out of he CFL and 
> use it on your UV light. Just remember chopped 168V non isolated power 
> will knock you off your chair.
>
> Craig
>
>