I have a question about rated power in a zerer-diode coupled in the protection unit in a esl57. I have seen several units with surface mount zeners but also seen its suitable with 5W rated zeners but only 1,25W available in surface mount like BZG03C220. Will it be ok? Or problem in a clipping situation with 10*1,25W= 12,5W terminated effect in treble unit?
See this thread:
https://www.diyaudio.com/community/threads/quad-esl-57-protection-using-gdt.265061/
I created a similar protection with BZT03C200 zener diodes and GP02-40 high voltage diodes, but never pushed it to kick in.
https://www.diyaudio.com/community/threads/quad-esl-57-protection-using-gdt.265061/
I created a similar protection with BZT03C200 zener diodes and GP02-40 high voltage diodes, but never pushed it to kick in.
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Ok thanks, that is similar in power handling 1,3W (BZT03C200) and mine suggested is 1,25W (BZG03C220)so pretty similar. I did test it with 1KV 2,5KV and it certainly works (clips at 2,2KV) but can it handle the power when used correctly? I just noticed its in different Power dissipation and also in 3,25W and thats alot more... do I need it?
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I do not use gas discharge tubes anymore. In the early 2000's I used to sue them but was finding that they were dying after a few years. I use the surface mount zeners and diode bridge as well.
My circuit board is here: https://oshpark.com/shared_projects/JiZ6X8Ye
Sheldon
My circuit board is here: https://oshpark.com/shared_projects/JiZ6X8Ye
Sheldon
Yes thanks. But do I need 5W power handling on each zener diode? Or is it okej with lower disipation capacity?
I use 1.25w surface mount diodes. That's a total of 12.5 watts across the string continuous rating. But thepulse handling is much higher, which is where the clamp typically operates. IF you pump a huge amount of power into it for a prolonged time, it will fry, but so will the 5w version. IT's all about keeping the junction temperature below about 150c. So if you have a super fast pulse, the string can take about 6000w, because the total energy is small due to the short time of the pulse.
It's your call, the 5w diode version would be 4 times more rugged, but still not foolproof. 1.25w diodes are much more readily available and cheap.
Sheldon
It's your call, the 5w diode version would be 4 times more rugged, but still not foolproof. 1.25w diodes are much more readily available and cheap.
Sheldon
I can't say for certain exactly how the gas tubes fail. years ago, I had two pairs of quads that developed treble panel problems that were actually the gas tubes clamping way way too low. That seemed odd to me, and I'm still not sure how that happens, but that was how I learned about the gas tube problems and stopped using them in favor of the diode and zener clamp. I suppose if they clamped too high, you wouldn't know about it until you needed it, which is hopefully never. so there could be failed gas tubes out there that I don't know about.
Anybody who burns a treble panel that I have rebuilt, I just rebuild it again for them no questions asked (this is just a hobby of mine, so I am pretty liberal with my support policy). But I've only had that with people who just send panels to be rebuilt and I don't have the chance to add a clamp board to their speakers.
Sheldon
Anybody who burns a treble panel that I have rebuilt, I just rebuild it again for them no questions asked (this is just a hobby of mine, so I am pretty liberal with my support policy). But I've only had that with people who just send panels to be rebuilt and I don't have the chance to add a clamp board to their speakers.
Sheldon
OK, good advice there. I fitted the gas diodes in mine that I've just rebuilt, so I think I'll live with them for a while and pick up a set of boards whenever I'm getting some pcbs made next. I've never used oshpark before, so it'll be good to try them out.
Coming back to this thread..... of course it is now very hard to find the diodes mentioned above.
Would BZD27C220PWH be a suitable replacement for the zeners? Max resistance is a tad higher - datasheet included below
BZG03C-220 datasheet is at https://www.vishay.com/docs/86138/bzg03c-m-series.pdf
On the rectifiers - GP02-30/40 have long lead times. How would R4000T from Rectron suit?
Datasheets seem to suggest they might be compatible.
Would BZD27C220PWH be a suitable replacement for the zeners? Max resistance is a tad higher - datasheet included below
BZG03C-220 datasheet is at https://www.vishay.com/docs/86138/bzg03c-m-series.pdf
On the rectifiers - GP02-30/40 have long lead times. How would R4000T from Rectron suit?
Datasheets seem to suggest they might be compatible.