Xenon flash tube can be triggered at low trigger voltages....why?

[grizedale]

This xenon flashtube datasheet says that it needs a trigger voltage of 6KV.

Xenon flash tube datasheet:
https://i47.tinypic.com/2gx2zb5.jpg


However, in our flashtube application, we are sucessfully triggering it with less than 2KV.


Will we get any problems as time goes on?....will the tubes age more quickly due to our low voltage triggering?

 

[barry]

You are operating the device outside its spec. The 6kV is a GUARANTEED minimum at which the manufacturer says the tube will fire. That, doesn't mean it WON'T fire at 2kV. I would be a little concerned about the reliability of your system operating so far out of spec. Your lifetime question would best be addressed to the manufacturer.

 

[pranam77]

Yes i do agree with "barry"..The manufacturer means, the triggering may go upto 6Kv. Now when you say u get it triggered at 2Kv, may be it is well triggered with it. But when life of the bulb falls below a level more volatge may be required or you need to replace the bulb to get coped with ur 2Kv triggering voltage. Next vital point to note is using a 6KV voltage will usually cause sparks jumping arround the tube to the negetive terminal which is quite hazardous..

 

[grizedale]

The thing is , highER voltage triggering is not really wanted.

You would always want to trigger at the lowest voltage you could get away with.

This is because a high trigger voltage presents enormous problems in terms of any moisture or humidity which may ingress into the flash tube enclosure...that moisture would be a nightmare with a higher trigger voltage.......the high voltage can also couple to circuit conductors.

So you would always want to trigger with the lowest voltage that you could.

But how do you know what this is?

 

[barry]

'You can't always git what you want.'

If the manufacturer says you need a minimum of 6kV to trigger the tube, you can't just arbitrarily say 'well, that's too high, I'm going to use 2kV' .

To answer your question, the way you know what the lowest voltage you can trigger with is to read the manufacturer's data sheet. You need to make your design work with the expected humidity etc., whether that means conformal coating, potting, water-tight enclosure, etc.

 

[godfreyl]

So you would always want to trigger with the lowest voltage that you could.

Yes, if you only want to use it yourself, today.

If you want to build it into a product and sell it to customers, then you should be concerned about whether it will still work a year from now.