Xenon flash tube parts question

[eem2am]

Hello,

Please could you help us in finding information on Xenon flash tubes and trigger transformer used in our newly modified xenon flash lamps?
(Questions are at the end)





We are making a trigger circuit for 1W,2W & 5W Xenon flash lamps.

We notice that in the following application note, (more than half way down on the right hand side of page 4) –it states that the polarity of the first high voltage trigger pulse to the xenon-tube-trigger-wire influences whether or not the tube will successfully flash……….


http://www.excelitas.com/downloads/app_applicationnotehighperformanceflash_final071004.pdf

We are using the AGA 0017 DDS4 Xenon flash tube from Excelitas, and we have no datasheet for it…….so we don’t know if the first trigger pulse needs to be positive or negative.

Can you tell us whether our first trigger pulse should be positive or negative?


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As an example here is a representative trigger circuit that makes the first trigger pulse positive.

SCHEMATIC 1:
http://i48.tinypic.com/335bpsp.jpg

Here is the waveform of the trigger transformer secondary (showing first pulse positive)

http://i50.tinypic.com/2dkmozt.jpg
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And example here is a representative trigger circuit that makes the first trigger pulse negative…

SCHEMATIC 2:
http://i45.tinypic.com/2d2ivsj.jpg
…SCHEMATIC 2 is our method of triggering.

And here is the waveform of the trigger transformer secondary (showing first pulse negative.)

http://i49.tinypic.com/2zqu74h.jpg
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So can you tell us whether our first trigger pulse should be positive or negative?

….and is “first-pulse-negative” triggering always a bad idea?

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Another point is that our Excelitas xenon flash tubes (from 1W to 5W) are of the following part numbers:-

AGA 0017 DDS4
AGA 0017 DDS2
BGA 0329 DDS1
AGA 0025 DDS1

We cannot find datasheets for any of these part numbers, and so we do not know what is the minimum required trigger pulse to the trigger electrode.
-Also, we do not know what is the maximum allowable trigger pulse to the tube’s trigger electrode.

Do you have any idea what this maximum and minimum trigger pulse voltage will be?

Excelitas have yet to respond to our questions.

We can only find a datasheet for a “AGA 0017” tube part number……
http://www.excelitas.com/downloads/dts_warningbeacons_final071004.pdf

…..however, it does not include the “DDS4” bit so we do not know if its our one.


These tubes are from a distributor who simply orders them , receives them and knows nothing else about them. (-these lamps were originally made by an old company which closed down and we took over…we are modifiying the lamps slightly and so need the datasheets now)

The surface mount trigger transformer that we are using is again by Excelitas, and again we do not have a datasheet for it……
-It is part number ZS1052-SUL(H) V02.

We can find a “ZS1052” part number, but its through hole….
http://www.excelitas.com/downloads/DTS_TriggerTransformers_final 071004.pdf

I have no idea if “ZS1052 SUL(H) V02” can be regarded as having the same phasing and turns ratio etc as the “ZS1052” part number(?)

Our trigger circuit is the same as in “SCHEMATIC 2” above.



Anyway, if you can answer the following it would be very helpful:-



QUESTIONS:
…-What is the maximum and minimum allowable trigger pulse to each of the above xenon tubes trigger electrode?

…-What is the required polarity of the first trigger pulse for each of the above tubes?

…-What (min/max) voltage is required across the above xenon tubes to allow them to flash over?

…-How do we find the datasheets for these xenon tubes and trigger transformer? (we’ve had no response from Excelitas)

…-Do you know of an alternative xenon tube & trigger transformer manufacturer just in case something has happened to Excelitas?
…..We are finding Xenon manufacturers these days are few and far between…..i guess tubes are going out of fashion?

 

[CDRIVE]

I did a search too but all my hits were you. I even found your post on the SparkFun forum. It's a rarity to not find data sheets. Sorry that I was of no help.

 

[john monks]

I cannot follow the schematics very well. So I think you will have to charge a capacitor in parallel with your tube to about 300 volts and place a pulse of opposite polarity of the voltage of the electrode closest to the trigger connection. However it looks like you are getting almost a sine wave on your trigger line so polarity may not make that much difference. My sole experience with flash tubes comes from energizing camera flash units with anywhere from 300 volts to 1000 volts and pulsing a flat piece of metal placed against the glass to about 200 volts through a transformer. My trigger waveform looked similar to yours. My trigger polarity did not seem to make any difference. I assume this is because the trigger voltage rings positive and negative anyway. Despite greatly overdriving the tube it still works.