Need help ID-ing Cap from Photoflash ***

The cheapo pocket size camera in front of me uses one 350V,330uF and is 22mm diameter x 40mm. Yours would not be

I just looked at a 20 yearold Siemens databook. B.... would be capacitor type number (yours not in my book, they only go to

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

Something doesn't work quite right there. A 1500u cap rated at 450v, would be the size of a can of beans !

And 20 years ago, a family economy sized one ...

Arfa

Siemens

to

I had not put any figures to it . But now doing so, scaling 22 to 40 and 40 to 63 mm gives a volume scaling of 5.25 so 5.25 x 330 gives 1730 uF So perhaps no increase from 350V then, presumably because 300 to 350V is what is required to strike an arc in zenon and larger flash tubes just require more energy, in amps terms for a given duration, after the initial arc

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

Volume today is much smaller but that's a start.

It would be worth trying a 450 V, several hundred uF cap and measure how high the voltage goes once the ready light comes on and it stabilizes.

You can also get an idea of how much energy it is producing during a flash compared to what it is supposed to.

CAUTION: Make sure it doesn't go above 450 V! Some electrolytics are 500 V or perhaps a bit more.

--- sam | Sci.Electronics.Repair FAQ:

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The one single flash charger I worked on maybe 20 years ago employed a voltage tripler circuit. I felt the wrath of it when I grabbed the wrong things trying to extricate it from its case using two pairs of hemostats.

On Wed, 21 Nov 2007 21:14:36 -0500, prc1 put finger to keyboard and composed:

I believe the "158" in "S9158" is the capacitance in pF. So 15 x 10^8 pf = 1500uF. I also believe the voltage rating is 360V.

See the following URLs:

Part Number Capacity Volts Type Notes Type

------------------------------------------------------------

http://209.85.173.104/search?q=cache:qnXc6ee87EsJ:photo.net/bboard/q-and-a-fetch-msg%3Fmsg_id%3D00GCpD+siemens+capacitor+flash&hl=en&ct=clnk&cd=4&client=opera Siemens/EPCOS B 43415-B9218-A000, 2100uF, 80.8mm H

The author states that the EPCOS B 43415 B9308 A000 capacitors are "more powerful".

- Franc Zabkar

On Fri, 23 Nov 2007 07:42:05 +1100, Franc Zabkar put finger to keyboard and composed:

This datasheet suggests that the voltage may be as high as 400V:

The "S9" seems to be related to the voltage rating in some way, or maybe it reflects the dimension and consequently the voltage rating.

- Franc Zabkar

I might be way off track here, but as far as I recall the majority of strobe light HV capacitors I`ve ever worked on were fairly low in value, tens or hundreds rather than thousands of muffs.

I have a very powerful 1960`s Metz flashgun here, the main storage cap is 160uF 350wv

Ron(UK)

In my (>20yo) Metz 45CT1 on the schematic the HV storage cap is listed as 1500uF

Sorry to the O/P, but I'm not about to disassemble it to check its physical dimensions.

On Fri, 23 Nov 2007 08:12:28 +1100, Franc Zabkar put finger to keyboard and composed:

The OP's stated dimensions of 1-9/16" diameter x 2.5" high correspond most closely to 40.8 mm x 65.8 mm.

From the above datasheet we have ...

volts uF dia height

-------------------------- 360 2100 40.8 65.8 400 2100 40.8 80.8 500 1000 40.8 65.8

Capacitance is proportional to plate area, so a taller cap will have a proportionally greater capacitance, all other things being equal.

To increase the voltage rating of a cap, one would need to increase the distance between its plates. Therefore a higher voltage cap of the same diameter would have less wraps and therefore a smaller plate area, and consequently a lower capacitance.

So if we take the first and second caps in the above table and reduce their capacitance from 2100uF to 1500uF, then their heights would be reduced in the same ratio.

expected height of 1500uF 400V cap = 80.8 x (1500/2100) = 57.7 mm expected height of 1500uF 360V cap = 65.8 x (1500/2100) = 47 mm

Assuming that the B43415/6 series caps are similar in construction to the B43405 series, then I would lean toward a 400V rating or better.

- Franc Zabkar

There's a lot of really good tips and info in this thread--thanks to all posters! I think I'll be following Franc's info and choose an appropriate sub from there. FWIW, the AC supply for this strobe sends three different voltages to the flash; the highest one of them is 350V @50 mA. I'm supposing that's DC, but it doesn't really matter...

budgie, I wouldn't ask you to disassemble yours. Your cap is probably marked like mine is, and that wouldn;t help anyway.

You didn't tell us which model Metz unit you have.

I actually gained the schematic and exploded view docs from the Aus agent for Metz after an emailed enquiry to the German factory. They are certainly more forthcoming than many manufacturers in this regard.

My 45CT1 had the neon illuninating before the cap had charged to the operating (i.e. firing) voltage. Fortunately there is a pot on the voltage divider which allows this to be recalibrated. Nice bits of gear, Metz.

I guess I should have said which model...the flash with the bad cap is a MecaTwin 60-40. I also have a 60CT-2 and a 45CT-4. The MecaTwin seem similar in size and design to the 45CT-4.

I'd love to get schematics for my units. I should email them... :)