Sorry, yes I measured that voltage. Thats the max the cap got to.

Well, that's why it doesn't work. That voltage is much too low.

 

To replace with LED's you would need a number of high-brightness LEDs facing in both directions for the double-sided flash lamp.
You likely will have to experiment to determine how many is required to give sufficient light (especially if it must be visible in sunlight).
Cree, for example, is a large supplier of high-brightness LEDs, including amber output types.

Once you determine how many you need, then a circuit can be designed to flash the LEDs.
For best efficiency since it's battery powered, you could charge a capacitor with a resonant inductor circuit and then discharge the capacitor through the same inductor into the LEDs.
Such a circuit should be able to put about 80% of the battery energy into the LEDs.

 

Sorry, yes I measured that voltage. Thats the max the cap got to.

You might try lifting one end of the cap, cliplead in a 400V cap (any value), and see what voltage it charges to.

 

Hi MrChips,
I was assuming that it was a surface mount IC (From picture 3) but looking again at picture 1 I agree that it is probably a transformer as it is too thick to be a surface mount IC. It has also occurred to me that the trigger coil is likely to be located close to the flash tube.

Les.

 

You might try lifting one end of the cap, cliplead in a 400V cap (any value), and see what voltage it charges to.

You might laugh at this - Sadly I don't have any. I don't have many components at all. Im just trying to fix this up for my unlce . Sorry.

 

Check the capacitor against the pdf here: https://www.hificollective.co.uk/components/fandt-axial-capacitors.html

I checked, but didn't find anything corresponding.

 

You might laugh at this - Sadly I don't have any. I don't have many components at all. Im just trying to fix this up for my unlce . Sorry.

Well, that makes it rather difficult to troubleshoot the circuit. :-(

 

To replace with LED's you would need a number of high-brightness LEDs facing in both directions for the double-sided flash lamp.
You likely will have to experiment to determine how many is required to give sufficient light (especially if it must be visible in sunlight).
Cree, for example, is a large supplier of high-brightness LEDs, including amber output types.

Once you determine how many you need, then a circuit can be designed to flash the LEDs.
For best efficiency since it's battery powered, you could charge a capacitor with a resonant inductor circuit and then discharge the capacitor through the same inductor into the LEDs.
Such a circuit should be able to put about 80% of the battery energy into the LEDs.

Could I simply use some eBay cob LED chips?

 

You could buy a read made alarm strobe such as this an put it in the original housing.

Les.

 

It sounds like the best alternative would be to replace the unit with some LEDs. With the original circuit, either the tube, the transformer of the power switching transistor could have gone, so it would need some probing to figure what.. be warned if its working the capacitor can give you quite a belt if you touch it!

For the LEDs you would need to get your hands dirty and build something yourself, maybe using some veroboard, a 555 timer IC or a MIC1555 and a Mosfet... if your pulsing the LEDs you can actually over power them considerably which make for very bright flashes, but you need some form of current limiting resistor you to make sure you don't toast the internal connections.
You might get away with over powering one of the COB LEDs you have suggested also.