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PCB light box - hf ballast / tube wattage

PCB light box - hf ballast / tube wattage

2012-08-01 by v321uk

When buying an HF ballast and fluorescent tube does the ballast wattage have to match the tube wattage?

Is it allowable to use an hf ballast of higher wattage that that of the tube  e.g. hf ballast 40W tube 12W ?

Can you parallel tubes to an hf ballast intended for a single tube so long as ballast wattage is sufficient ?

I am building a uv-a  light box for sensitised PCB exposure and am not sure how many tubes to use.
I am thinking get a higher wattage than needed hf ballast and say two 8 or 12W tubes so if there is insufficient light I could get one or two more tubes and parallel them.

I usually use the sun for exposure but there has not been much of it here over the last few weeks and I need to make a PCB.

Thanks 
John G3UGY

Re: [Homebrew_PCBs] PCB light box - hf ballast / tube wattage - 400W floodlight instead?

2012-08-01 by Robin Whittle

Hi John,

Generally, gas discharge tubes cannot be operated in parallel.  They
need a high voltage to start, but settle down to a low voltage ca. 90
volts (I guess) once they are conducting.   With ordinary inductor
ballasts I have seen two 20W short tubes, each with their own starter,
wired in series with a 40W ballast.  This is for 240V.  Maybe that would
work with a high frequency electronic ballast.

I chose to use a 500 watt floodlamp from the hardware store.  The short
linear quartz halogen lamps give off a lot of near UV, which is what I
want for exposing Riston negative photoresist.

At a distance of about 45cm I have exposure times of 2 to 3 minutes.

This is a much narrower angle source of light than having a bunch of
fluorescent tubes only 10cm away, so for a given phototool and possible
distance from the phototool to the top and bottom of the Riston, I get a
much sharper image (shadow).

The only potential concern I can think of is heating of the phototool,
PCB and whatever means is used to hold them together.  I have a fan
blowing on them to keep them cool.

There's no warm-up time for a QI light.  Tubular fluorescent lamps are
likely to have some kind of warm-up time, making it difficult to predict
their light output unless they have just been running and are fully
warmed up.  High pressure mercury vapor lamps have much longer warm-up
times, and so do the compact fluorescent lamps which are now widely
used.  All these fluorescent lamps - tubular, 400W (or other wattage)
high pressure mercury vapor lamps, and compact fluorescent lamps - come
in "black light" versions which I think put out the ideal wavelength for
exposing Riston.


http://www2.dupont.com/Imaging_Materials/en_US/tech_info/datasheets/index.html

I haven't looked at all the types, but the types I have looked at are
specified to respond best to 350 to 380nm light.  This datasheet for a
400W high pressure mercury vapour fluorescent H500-BL:

  http://www.eyelighting.com/tb/Mercury/MVR/EQS-N-52-78-69917.pdf

shows most of the output at about 370nm.

However, I think their warm-up times are a problem.

QI lamps will vary their near UV output somewhat according to their
operating voltage, but unless the mains voltage varies widely, I would
be surprised if this variation was enough to cause trouble with Riston.


 - Robin             http://www.firstpr.com.au/pcb-diy/

Re: [Homebrew_PCBs] PCB light box - hf ballast / tube wattage

2012-08-01 by Paul

Hi John

I don't know about the ballast question, in my old commercial but 
un-branded box which I got from a rally it matches the tubes.

Mine has 2 x 8W 29cm tubes which are fine for exposing the size of 
boards I make. The clear glass area is 15 x 25cm and the tubes are 
spaced 9cm apart. There's a flat foil reflector behind the tubes. 
Exposure time with Mega pre-sensitised board is about 3 minutes.

Curious what you are going to do for a timer? Mine doesn't have one and 
fitting one is on the list of things to do in the shack.

Regards

Paul G4DCV

On 01/08/2012 07:50, v321uk wrote:
>
> When buying an HF ballast and fluorescent tube does the ballast 
> wattage have to match the tube wattage?
>
> Is it allowable to use an hf ballast of higher wattage that that of 
> the tube e.g. hf ballast 40W tube 12W ?
>
> Can you parallel tubes to an hf ballast intended for a single tube so 
> long as ballast wattage is sufficient ?
>
> I am building a uv-a light box for sensitised PCB exposure and am not 
> sure how many tubes to use.
> I am thinking get a higher wattage than needed hf ballast and say two 
> 8 or 12W tubes so if there is insufficient light I could get one or 
> two more tubes and parallel them.
>
> I usually use the sun for exposure but there has not been much of it 
> here over the last few weeks and I need to make a PCB.
>
> Thanks
> John G3UGY
>
> 
>
> No virus found in this message.
> Checked by AVG - www.avg.com <http://www.avg.com>
> Version: 2012.0.2197 / Virus Database: 2437/5167 - Release Date: 07/31/12
>



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

Re: [Homebrew_PCBs] PCB light box - hf ballast / tube wattage - 400W floodlight instead?

2012-08-01 by Russell Shaw

On 01/08/12 17:18, Robin Whittle wrote:
> Hi John,
>
> Generally, gas discharge tubes cannot be operated in parallel...

I got a 380nm 10W LED. I haven't tried it yet.

<http://www.ebay.com.au/itm/10W-Ultra-Violet-UV-High-Power-Led-Light-380nm-385nm-/230760896509?pt=LH_DefaultDomain_0&hash=item35ba6bd7fd>

You can get a 100W one for "only" $999.99 ;)

<http://www.ebay.com.au/itm/380nm-385nm-Ultra-Violet-UV-High-Power-LED-Light-100W-/360445882648?pt=LH_DefaultDomain_0&hash=item53ec3fb118>


I was going to try it for curing UV glue and ink, but it would probably do good 
for photoresist too.

An array of 1W LEDs could be an option too.


Do not stare at these when illuminated. It could cause photopolymerisation 
(cloudiness) in the eye.

Re: [Homebrew_PCBs] PCB light box - hf ballast / tube wattage - 400W floodlight instead?

2012-08-01 by John Anhalt

Regarding parallel vs. series, wouldn't putting the bulbs in series decrease the starting voltage available for each?  In series, they share the same current, and in parallel, the voltage drop across each is the same.  So much for theory.

Actually, it is a bit more complex than that.  Here is a rather lengthy discussion by Philips:http://www.advance.philips.com/documents/uploads/literature/1-01%20to%201-69_Atlas2012.pdf

Page I-7 discusses parallel vs. series.  Page I-35 begins a section on wiring.  Note that for high-frequency devices, there are other considerations.  The best answer might be to look up your specific ballast to see how it should be wired for multiple bulbs.  

Parallel vs. series may be complicated by the nomenclature used.  If the bulbs share a common (e.g., white wire), then I would say they can't be in series.  

John
Show quoted textHide quoted text
  ----- Original Message ----- 
  From: Robin Whittle 
  To: Homebrew_PCBs@yahoogroups.com 
  Cc: v321uk 
  Sent: Wednesday, August 01, 2012 3:18 AM
  Subject: Re: [Homebrew_PCBs] PCB light box - hf ballast / tube wattage - 400W floodlight instead?


    
  Hi John,

  Generally, gas discharge tubes cannot be operated in parallel. They
  need a high voltage to start, but settle down to a low voltage ca. 90
  volts (I guess) once they are conducting. With ordinary inductor
  ballasts I have seen two 20W short tubes, each with their own starter,
  wired in series with a 40W ballast. This is for 240V. Maybe that would
  work with a high frequency electronic ballast.

  I chose to use a 500 watt floodlamp from the hardware store. The short
  linear quartz halogen lamps give off a lot of near UV, which is what I
  want for exposing Riston negative photoresist.

  At a distance of about 45cm I have exposure times of 2 to 3 minutes.

  This is a much narrower angle source of light than having a bunch of
  fluorescent tubes only 10cm away, so for a given phototool and possible
  distance from the phototool to the top and bottom of the Riston, I get a
  much sharper image (shadow).

  The only potential concern I can think of is heating of the phototool,
  PCB and whatever means is used to hold them together. I have a fan
  blowing on them to keep them cool.

  There's no warm-up time for a QI light. Tubular fluorescent lamps are
  likely to have some kind of warm-up time, making it difficult to predict
  their light output unless they have just been running and are fully
  warmed up. High pressure mercury vapor lamps have much longer warm-up
  times, and so do the compact fluorescent lamps which are now widely
  used. All these fluorescent lamps - tubular, 400W (or other wattage)
  high pressure mercury vapor lamps, and compact fluorescent lamps - come
  in "black light" versions which I think put out the ideal wavelength for
  exposing Riston.

  http://www2.dupont.com/Imaging_Materials/en_US/tech_info/datasheets/index.html

  I haven't looked at all the types, but the types I have looked at are
  specified to respond best to 350 to 380nm light. This datasheet for a
  400W high pressure mercury vapour fluorescent H500-BL:

  http://www.eyelighting.com/tb/Mercury/MVR/EQS-N-52-78-69917.pdf

  shows most of the output at about 370nm.

  However, I think their warm-up times are a problem.

  QI lamps will vary their near UV output somewhat according to their
  operating voltage, but unless the mains voltage varies widely, I would
  be surprised if this variation was enough to cause trouble with Riston.

  - Robin http://www.firstpr.com.au/pcb-diy/



  

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

"10 watt" 380nm UV LED for exposing photoresist

2012-08-01 by Robin Whittle

Hi Russell,

In "Re: [Homebrew_PCBs] PCB light box - hf ballast / tube wattage - 400W
floodlight instead?" you wrote:

> I got a 380nm 10W LED. I haven't tried it yet.
> 
> http://www.ebay.com.au/itm/10W-Ultra-Violet-UV-High-Power-Led-Light-380nm-385nm-/230760896509

Wow!!!

> You can get a 100W one for "only" $999.99 ;)
> 
> http://www.ebay.com.au/itm/380nm-385nm-Ultra-Violet-UV-High-Power-LED-Light-100W-/360445882648

I think the 10 watt (power consumption) one would do the trick.  In
PCB-DIY I don't think we are in a tearing hurry for exposure time.

I think you would need to attach it to a fancy heatsink, with
appropriate heat conductive paste, to keep it cool and happy.

This would make a very small angle source of UV for exposing Riston and
the like.  This would make it less critical to get the phototool in
close contact with the Riston.

I don't know what the UV output of the 400W floodlight is.  However it
should be possible to guess an exposure time at a similar distance - in
my case 45cm for this LED.  Let's say this LED put out 70% of its light
on an area 50cm x 50cm.  Assuming it puts out 1 watt (as the eBay
listing suggests, for ~1000mA at ~10 volts) then this is 7 watts on 0.25
square metres, or 28 watts per square metre = 2.8 x 10^1 watts per
square metre.  This is 2.8 x 10^-3 watts (2.8 milliwatts) per square cm.

Looking at a Riston datasheet, for MM540:

http://www2.dupont.com/Imaging_Materials/en_US/assets/downloads/datasheets/mm500series.pdf

the exposure energy for 350 to 380nm is (table on bottom right of page
2) 25 to 55 millijoules per square cm.

So according to theory, this LED should expose the Riston in 10 to 20
seconds!

For larger boards, to get an even exposure, it would make sense to move
the LED to a greater distance, with exposure time quadrupling for each
doubling of distance.

A significant advantage of this LED compared to the 400W floodlight is
no significant heating of the PCB and phototool, and therefore no need
for a fan.

> I was going to try it for curing UV glue and ink, but it would
> probably do good for photoresist too.

I think it would be excellent for all these purposes.

> An array of 1W LEDs could be an option too.

Yes.

> Do not stare at these when illuminated. It could cause
> photopolymerisation (cloudiness) in the eye.

Unlike a quartz halogen floodlight, which is seriously bright, the UV
LED may not seem vary bright to the eye.  I guess it would activate our
retina to some extent, since it is so bright and since its spectrum
presumably has some width extending into our violet range:

  http://en.wikipedia.org/wiki/Cone_cell

I think eye protection would be essential for a device like this.  I
wear sunglasses when operating the 400W floodlight.  Maybe that would be
sufficient, since this is near-UV, not the same as shorter-wavelength
mutation-producing UVB which causes sunburn and cancer.

  - Robin          http://www.firstpr.com.au/pcb-diy/

Re: PCB light box - hf ballast / tube wattage

2012-08-01 by v321uk

Hi Paul,

Thanks for the info on the commercial unit.
Re timer as I need to make a board asap I'll just do it with clock and switch initially.

Thanks, John G3UGY

 

--- In Homebrew_PCBs@yahoogroups.com, Paul <paul@...> wrote:
Show quoted textHide quoted text
>
> Hi John
> 
> I don't know about the ballast question, in my old commercial but 
> un-branded box which I got from a rally it matches the tubes.
> 
> Mine has 2 x 8W 29cm tubes which are fine for exposing the size of 
> boards I make. The clear glass area is 15 x 25cm and the tubes are 
> spaced 9cm apart. There's a flat foil reflector behind the tubes. 
> Exposure time with Mega pre-sensitised board is about 3 minutes.
> 
> Curious what you are going to do for a timer? Mine doesn't have one and 
> fitting one is on the list of things to do in the shack.
> 
> Regards
> 
> Paul G4DCV

Re: PCB light box - hf ballast / tube wattage - 400W floodlight instead?

2012-08-01 by v321uk

Hi Robin,

Thanks for the comprehensive info.

Do you think a car quartz halogen headlamp would have sufficient UV output ? 
I have a new 12V dual filament 50W + 65W which I could parallel to give 115W

Alternatively, I have a new 12W T5 circular (11cm     41/2")  Fly Zapper tube.

My PC is only 8cm  x  3cm.

The sensitised PCB needs energy around 360nm. 

Thanks,
John  



--- In Homebrew_PCBs@yahoogroups.com, Robin Whittle <rw@...> wrote:
Show quoted textHide quoted text
>
> Hi John,
> 
> Generally, gas discharge tubes cannot be operated in parallel.  They
> need a high voltage to start, but settle down to a low voltage ca. 90
> volts (I guess) once they are conducting.   With ordinary inductor
> ballasts I have seen two 20W short tubes, each with their own starter,
> wired in series with a 40W ballast.  This is for 240V.  Maybe that would
> work with a high frequency electronic ballast.
> 
> I chose to use a 500 watt floodlamp from the hardware store.  The short
> linear quartz halogen lamps give off a lot of near UV, which is what I
> want for exposing Riston negative photoresist.
> 
> At a distance of about 45cm I have exposure times of 2 to 3 minutes.
> 
> This is a much narrower angle source of light than having a bunch of
> fluorescent tubes only 10cm away, so for a given phototool and possible
> distance from the phototool to the top and bottom of the Riston, I get a
> much sharper image (shadow).
> 
> The only potential concern I can think of is heating of the phototool,
> PCB and whatever means is used to hold them together.  I have a fan
> blowing on them to keep them cool.
> 
> There's no warm-up time for a QI light.  Tubular fluorescent lamps are
> likely to have some kind of warm-up time, making it difficult to predict
> their light output unless they have just been running and are fully
> warmed up.  High pressure mercury vapor lamps have much longer warm-up
> times, and so do the compact fluorescent lamps which are now widely
> used.  All these fluorescent lamps - tubular, 400W (or other wattage)
> high pressure mercury vapor lamps, and compact fluorescent lamps - come
> in "black light" versions which I think put out the ideal wavelength for
> exposing Riston.
> 
> 
> http://www2.dupont.com/Imaging_Materials/en_US/tech_info/datasheets/index.html
> 
> I haven't looked at all the types, but the types I have looked at are
> specified to respond best to 350 to 380nm light.  This datasheet for a
> 400W high pressure mercury vapour fluorescent H500-BL:
> 
>   http://www.eyelighting.com/tb/Mercury/MVR/EQS-N-52-78-69917.pdf
> 
> shows most of the output at about 370nm.
> 
> However, I think their warm-up times are a problem.
> 
> QI lamps will vary their near UV output somewhat according to their
> operating voltage, but unless the mains voltage varies widely, I would
> be surprised if this variation was enough to cause trouble with Riston.
> 
> 
>  - Robin             http://www.firstpr.com.au/pcb-diy/
>

12 volt QI headlight lamp as UV source for exposing photoresist?

2012-08-01 by Robin Whittle

Hi John,

I am responding to your message in: "Re: PCB light box - hf ballast /
tube wattage - 400W floodlight instead?", in which you wrote:

> Do you think a car quartz halogen headlamp would have sufficient UV
> output ? I have a new 12V dual filament 50W + 65W which I could
> parallel to give 115W.

> My PC is only 8cm  x  3cm.

I guess a quartz iodide (AKA quartz halogen) headlight lamp would work
OK with a distance suitable for small boards and with a few minutes for
exposure.  However it would depend greatly on the voltage you ran it
from.  The UV output of an incandescent filament goes up dramatically
with its temperature, so if you ran it from 11 volts and got little
action, and from 13 volts and got a much greater UV output, I wouldn't
be surprised.

With these currents and voltages I think it would be good to use thick
wires and measure the voltage at the lamp terminals.  I suggest running
it at 13.8 volts - which is a typical maximum voltage in a car.

Some kind of reflector, such as made from a nicely bent fragment of
aluminium pie dish would help.

As with the 400W quartz halogen floodlamp, I think heating of the board
might be a problem.  A fan blowing on the board should fix this.


> Alternatively, I have a new 12W T5 circular (11cm 41/2")  Fly Zapper
> tube.
>
> The sensitised PCB needs energy around 360nm.

I don't know what their output wavelengths are, but as far as I know
they are not in the 350 to 380nm near UV range.  Do you have a tube
number?  Googling it should turn up a spec sheet.


  - Robin          http://www.firstpr.com.au/pcb-diy/

Re: 12 volt QI headlight lamp as UV source for exposing photoresist?

2012-08-01 by John

The quartz halogen car headlamp bulb successfully exposed the PCB.
I ran the bulb at 13.8V with just the 65W filament connected at a distance of about 4" from the PCB for three and a half minutes.

The artwork was produced with SprintLayout v5 and inkjet printed with a canon MP600 on to regular A4 copy paper with printer set
to highest quality.  I took the inkjet print to a copy centre who  photocopied it at darkest setting on to what looked like 
tracing paper but was probably a plastic material they use to print technical drawings.

I will probably get a number lower wattage quartz halogen car bulbs and make up a light exposure box.  Quartz halogen car bulbs 
are easily obtainable and not too expensive and no ballast is needed.

I did the test on an old piece of SRBP.   I'll repeat it with some new RS glass epoxy FR-4.

John G3UGY


--------------------------------------------------
From: "Robin Whittle" <rw@...>
Sent: Wednesday, August 01, 2012 3:01 PM
To: <Homebrew_PCBs@yahoogroups.com>
Cc: "v321uk" <v321uk@...>
Show quoted textHide quoted text
Subject: 12 volt QI headlight lamp as UV source for exposing photoresist?

> Hi John,
>
> I am responding to your message in: "Re: PCB light box - hf ballast /
> tube wattage - 400W floodlight instead?", in which you wrote:
>
>> Do you think a car quartz halogen headlamp would have sufficient UV
>> output ? I have a new 12V dual filament 50W + 65W which I could
>> parallel to give 115W.
>
>> My PC is only 8cm  x  3cm.
>
> I guess a quartz iodide (AKA quartz halogen) headlight lamp would work
> OK with a distance suitable for small boards and with a few minutes for
> exposure.  However it would depend greatly on the voltage you ran it
> from.  The UV output of an incandescent filament goes up dramatically
> with its temperature, so if you ran it from 11 volts and got little
> action, and from 13 volts and got a much greater UV output, I wouldn't
> be surprised.
>
> With these currents and voltages I think it would be good to use thick
> wires and measure the voltage at the lamp terminals.  I suggest running
> it at 13.8 volts - which is a typical maximum voltage in a car.
>
> Some kind of reflector, such as made from a nicely bent fragment of
> aluminium pie dish would help.
>
> As with the 400W quartz halogen floodlamp, I think heating of the board
> might be a problem.  A fan blowing on the board should fix this.
>
>
>> Alternatively, I have a new 12W T5 circular (11cm 41/2")  Fly Zapper
>> tube.
>>
>> The sensitised PCB needs energy around 360nm.
>
> I don't know what their output wavelengths are, but as far as I know
> they are not in the 350 to 380nm near UV range.  Do you have a tube
> number?  Googling it should turn up a spec sheet.
>
>
>  - Robin          http://www.firstpr.com.au/pcb-diy/
>

Re: 12 volt QI headlight lamp as UV source for exposing photoresist?

2012-08-01 by v321uk

Robin, 

Fly Zapper tubes are around 350nm but will be changing soon to 368nm

The following from:
http://www.lamps-on-line.com/uv-lightbulbs/blacklight-bl350.html

Application:
The most popular application for BL350 bulbs is in Bug Zappers or Fly Killers.

They can also be used for Nail Curing, photopolymerisation and curing of plastics and varnishes.

Technical:
bulbs emit UV Radiation at 350nm.

Recent changes to legislation (RoHS compliance) has meant that
lamps in the near future will emit UV radiation at 368nm.

Although called Black Light BL350 bulbs are white in appearance and have the same electrical characteristics as standard fluorescent tubes.

John G3UGY


--- In Homebrew_PCBs@yahoogroups.com, Robin Whittle <rw@...> wrote:
Show quoted textHide quoted text
> > The sensitised PCB needs energy around 360nm.
> 
> I don't know what their output wavelengths are, but as far as I know
> they are not in the 350 to 380nm near UV range.  Do you have a tube
> number?  Googling it should turn up a spec sheet.
> 
>   - Robin          http://www.firstpr.com.au/pcb-diy/

Re: PCB light box - hf ballast / tube wattage - 400W floodlight instead?

2012-08-01 by v321uk

Robin,

Does your 500W halogen connect directly to the mains or does it need a ballast or current limiter?

Do you use a base (socket) how do you connect to the bulb?

Thanks,
John G3UGY
Show quoted textHide quoted text
> --- In Homebrew_PCBs@yahoogroups.com, Robin Whittle <rw@> wrote:
> >
> > Hi John,
> > 
> > Generally, gas discharge tubes cannot be operated in parallel.  They
> > need a high voltage to start, but settle down to a low voltage ca. 90
> > volts (I guess) once they are conducting.   With ordinary inductor
> > ballasts I have seen two 20W short tubes, each with their own starter,
> > wired in series with a 40W ballast.  This is for 240V.  Maybe that would
> > work with a high frequency electronic ballast.
> > 
> > I chose to use a 500 watt floodlamp from the hardware store.  The short
> > linear quartz halogen lamps give off a lot of near UV, which is what I
> > want for exposing Riston negative photoresist.
> > 
> > At a distance of about 45cm I have exposure times of 2 to 3 minutes.
> > 
> > This is a much narrower angle source of light than having a bunch of
> > fluorescent tubes only 10cm away, so for a given phototool and possible
> > distance from the phototool to the top and bottom of the Riston, I get a
> > much sharper image (shadow).
> > 
> > The only potential concern I can think of is heating of the phototool,
> > PCB and whatever means is used to hold them together.  I have a fan
> > blowing on them to keep them cool.
> > 
> > There's no warm-up time for a QI light.  Tubular fluorescent lamps are
> > likely to have some kind of warm-up time, making it difficult to predict
> > their light output unless they have just been running and are fully
> > warmed up.  High pressure mercury vapor lamps have much longer warm-up
> > times, and so do the compact fluorescent lamps which are now widely
> > used.  All these fluorescent lamps - tubular, 400W (or other wattage)
> > high pressure mercury vapor lamps, and compact fluorescent lamps - come
> > in "black light" versions which I think put out the ideal wavelength for
> > exposing Riston.
> > 
> > 
> > http://www2.dupont.com/Imaging_Materials/en_US/tech_info/datasheets/index.html
> > 
> > I haven't looked at all the types, but the types I have looked at are
> > specified to respond best to 350 to 380nm light.  This datasheet for a
> > 400W high pressure mercury vapour fluorescent H500-BL:
> > 
> >   http://www.eyelighting.com/tb/Mercury/MVR/EQS-N-52-78-69917.pdf
> > 
> > shows most of the output at about 370nm.
> > 
> > However, I think their warm-up times are a problem.
> > 
> > QI lamps will vary their near UV output somewhat according to their
> > operating voltage, but unless the mains voltage varies widely, I would
> > be surprised if this variation was enough to cause trouble with Riston.
> > 
> > 
> >  - Robin             http://www.firstpr.com.au/pcb-diy/
> >
>

RE: [Homebrew_PCBs] PCB light box - hf ballast / tube wattage

2012-08-01 by Nuno T.

Hi John,

Don't have much experience with different exposure lamps to say which one is
better, but can give you some solid info on the HF ballasts vs tube wattage:

The power supplied by a HF electronic ballast must match the tube power
rating. There's a small allowable margin, but less than specified and the
lamp either won't light up or will light very dimly and flickering a lot. To
much and it will either blow it's filaments or will have a very short life.
Using an under rated ballast has no destructive effect that I know of, only
the lamp won't give it's full rated light level, if any.

HF electronic ballasts don't allow any type of parallel/series connections
has it happens with magnetic ballasts for 20W/18W type. There's some models
that can run several tubes from the same unit, but they have different
connectors for each lamp.

eBay has some cheap, and good enough models. Search like: "electronic
ballast 18W T8" or "ballast 2x14W T5" (there's no magnetic ballasts for T5
lamps, so no need to specify that in the search)  Clalight seems to be the
best brand for price/performance ratio.

Nuno T.
Show quoted textHide quoted text
> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com 
> [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of v321uk
> Sent: quarta-feira, 1 de Agosto de 2012 7:51
> To: Homebrew_PCBs@yahoogroups.com
> Subject: [Homebrew_PCBs] PCB light box - hf ballast / tube wattage
> 
> When buying an HF ballast and fluorescent tube does the 
> ballast wattage have to match the tube wattage?
> 
> Is it allowable to use an hf ballast of higher wattage that 
> that of the tube  e.g. hf ballast 40W tube 12W ?
> 
> Can you parallel tubes to an hf ballast intended for a single 
> tube so long as ballast wattage is sufficient ?
> 
> I am building a uv-a  light box for sensitised PCB exposure 
> and am not sure how many tubes to use.
> I am thinking get a higher wattage than needed hf ballast and 
> say two 8 or 12W tubes so if there is insufficient light I 
> could get one or two more tubes and parallel them.
> 
> I usually use the sun for exposure but there has not been 
> much of it here over the last few weeks and I need to make a PCB.
> 
> Thanks
> John G3UGY
> 
> 
> 
> 
> ------------------------------------
> 
> Be sure to visit the group home and check for new Links, 
> Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
> 
> 
>

Re: [Homebrew_PCBs] Re: PCB light box - hf ballast / tube wattage - 400W floodlight instead?

2012-08-02 by Robin Whittle

Hi John,

You wrote:

> Does your 500W halogen connect directly to the mains or does it need
> a ballast or current limiter?
>
> Do you use a base (socket) how do you connect to the bulb?

The floodlight is a yellow aluminium device with a glass cover and a
steel frame for sitting on the ground.  It is intended for building
sites and the like.  I took the glass cover off and used it for other
purposes.  This may slightly improve the UV output, but the main reason
I did so was because I have mine shining downwards and I wanted to
improve air flow around the lamp.  I left the wire frame safety guard in
place, so it is unlikely that I or anyone else is going to stick their
fingers into it while it is turned on.

I think these are produced in vast numbers in China, so the same
products are likely to be available in most countries, for instance:

http://www.jastimber.co.uk/products/electrical/lighting-floodlights/floodlight-portable-500w-fppsl500p-product.html

http://quickbit.co.uk/site-lights-task-lights-portable-floodlight

http://porlite.en.made-in-china.com/product/BbvECrcTbeYR/China-500W-Portable-Halogen-Worklight-YL1009-.html

I paid Australian $16 for mine at the nearby hardware store.  These
floodlighs use a small tubular filament lamp 119mm long, such as:

http://www.lamps-on-line.com/halogen-lights/linear-halogen/standard-linear-halogen/240v-500w-r7s-119mm.html

There's no ballast, since it is not a gas discharge tube.

  - Robin             http://www.firstpr.com.au/pcb-diy/

RE: [Homebrew_PCBs] Re: PCB light box - hf ballast / tube wattage - 400W floodlight instead?

2012-08-02 by Boman33

Preferably keep a fan blowing over your artwork & PCB.  The lamp produces a
lot of heat- 500W.

 

I am literarily using lamps like that for a specialized heater to melt
plastic. 9 of them mounted side by side in a 3x3 array.  4.5kW!

Bertho
Show quoted textHide quoted text
From:  Robin Whittle   Sent: Thursday, August 02, 2012 00:07



Hi John,

You wrote:

> Does your 500W halogen connect directly to the mains or does it need
> a ballast or current limiter?
>
> Do you use a base (socket) how do you connect to the bulb?

The floodlight is a yellow aluminium device with a glass cover and a
steel frame for sitting on the ground. It is intended for building
sites and the like. I took the glass cover off and used it for other
purposes. This may slightly improve the UV output, but the main reason
I did so was because I have mine shining downwards and I wanted to
improve air flow around the lamp. I left the wire frame safety guard in
place, so it is unlikely that I or anyone else is going to stick their
fingers into it while it is turned on.

I think these are produced in vast numbers in China, so the same
products are likely to be available in most countries, for instance:

http://www.jastimber.co.uk/products/electrical/lighting-floodlights/floodlig
ht-portable-500w-fppsl500p-product.html

http://quickbit.co.uk/site-lights-task-lights-portable-floodlight

http://porlite.en.made-in-china.com/product/BbvECrcTbeYR/China-500W-Portable
-Halogen-Worklight-YL1009-.html

I paid Australian $16 for mine at the nearby hardware store. These
floodlighs use a small tubular filament lamp 119mm long, such as:

http://www.lamps-on-line.com/halogen-lights/linear-halogen/standard-linear-h
alogen/240v-500w-r7s-119mm.html

There's no ballast, since it is not a gas discharge tube.

- Robin http://www.firstpr.com.au/pcb-diy/



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

Re: [Homebrew_PCBs] Re: PCB light box - hf ballast / tube wattage - 400W floodlight instead?

2012-08-02 by John

Thanks Robin,

I just realised that I already have one of those stashed away in the garage.... I'll dig it out.

John
Show quoted textHide quoted text
> The floodlight is a yellow aluminium device with a glass cover and a
> steel frame for sitting on the ground.  It is intended for building
> sites and the like.  I took the glass cover off and used it for other
> purposes.  This may slightly improve the UV output, but the main reason
> I did so was because I have mine shining downwards and I wanted to
> improve air flow around the lamp.  I left the wire frame safety guard in
> place, so it is unlikely that I or anyone else is going to stick their
> fingers into it while it is turned on.
 
>  - Robin             http://www.firstpr.com.au/pcb-diy/

Re: [Homebrew_PCBs] PCB light box - hf ballast / tube wattage

2012-08-02 by John

Hi Nuno T,

Thanks for the info on ballasts and tube Wattage.  
I have often wondered whether they need to be matched.

Cheers,
John
Show quoted textHide quoted text
From: Nuno T. 
Sent: Wednesday, August 01, 2012 9:54 PM
To: Homebrew_PCBs@yahoogroups.com 
Subject: RE: [Homebrew_PCBs] PCB light box - hf ballast / tube wattage


  
Hi John,

Don't have much experience with different exposure lamps to say which one is
better, but can give you some solid info on the HF ballasts vs tube wattage:

The power supplied by a HF electronic ballast must match the tube power
rating. There's a small allowable margin, but less than specified and the
lamp either won't light up or will light very dimly and flickering a lot. To
much and it will either blow it's filaments or will have a very short life.
Using an under rated ballast has no destructive effect that I know of, only
the lamp won't give it's full rated light level, if any.

HF electronic ballasts don't allow any type of parallel/series connections
has it happens with magnetic ballasts for 20W/18W type. There's some models
that can run several tubes from the same unit, but they have different
connectors for each lamp.

eBay has some cheap, and good enough models. Search like: "electronic
ballast 18W T8" or "ballast 2x14W T5" (there's no magnetic ballasts for T5
lamps, so no need to specify that in the search) Clalight seems to be the
best brand for price/performance ratio.

Nuno T.

> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com 
> [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of v321uk
> Sent: quarta-feira, 1 de Agosto de 2012 7:51
> To: Homebrew_PCBs@yahoogroups.com
> Subject: [Homebrew_PCBs] PCB light box - hf ballast / tube wattage
> 
> When buying an HF ballast and fluorescent tube does the 
> ballast wattage have to match the tube wattage?
> 
> Is it allowable to use an hf ballast of higher wattage that 
> that of the tube e.g. hf ballast 40W tube 12W ?
> 
> Can you parallel tubes to an hf ballast intended for a single 
> tube so long as ballast wattage is sufficient ?
> 
> I am building a uv-a light box for sensitised PCB exposure 
> and am not sure how many tubes to use.
> I am thinking get a higher wattage than needed hf ballast and 
> say two 8 or 12W tubes so if there is insufficient light I 
> could get one or two more tubes and parallel them.
> 
> I usually use the sun for exposure but there has not been 
> much of it here over the last few weeks and I need to make a PCB.
> 
> Thanks
> John G3UGY
> 
> 
> 
> 
> ------------------------------------
> 
> Be sure to visit the group home and check for new Links, 
> Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
> 
> 
> 





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