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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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14th Oct 2018, 3:31 am | #21 |
Dekatron
Join Date: Dec 2007
Location: Haarlem, Netherlands
Posts: 4,199
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Re: Miniature relay Suppressor
That Okaya RC circuit at Farnell, might be an impregnated paper capacitor since there is no mention of the dielectric in the datasheet. While undoubtedly better than those from RIFA, the only reasonably reliable way to use paper in a capacitor is in a hermetically sealed glass or tin can using choice materials and a bit of luck. While some plastic foil capacitors are cheap and unreliable, on average/on a technology level they are much better than any but the most expensive paper capacitors. Those Russian paper ones linked by Argus25 are probably quite good.
After reading the manufacturers documentation https://www.okayaelec.co.jp/dcms_med...eg1704_all.pdf from page 52 onward, there's a lot of useful information also on selecting the right value but not a word about the dielectric. I'd say a 50/50 chance on polypropylene or paper. |
14th Oct 2018, 9:45 pm | #22 |
Nonode
Join Date: Oct 2017
Location: Bristol, UK.
Posts: 2,384
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Re: Miniature relay Suppressor
Hi Maarten, Thanks for your inputs. Is this polyprop film cap from RS Components a better option? https://uk.rs-online.com/mobile/p/po...itors/8829461/
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14th Oct 2018, 11:59 pm | #23 |
Dekatron
Join Date: Dec 2007
Location: Haarlem, Netherlands
Posts: 4,199
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Re: Miniature relay Suppressor
Epcos is a good brand but this type isn't (according to the data sheet) rated for anything else than across the mains usage, even though a series resistor would prevent some of the inevitable detoriation. You could try and mail Farnell, Roxburgh or Okaya and ask what dielectric their RC unit uses. The built in resistor does make it more convenient so if it's indeed polypropylene there's a good reason to use it. A good pulse rated polyprop capacitor without built in resistor would be a Wima FKP1 series. I'd choose the 1kV working voltage one as I think 630V may be just a bit on the low side.
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15th Oct 2018, 5:07 pm | #24 |
Nonode
Join Date: Oct 2017
Location: Bristol, UK.
Posts: 2,384
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Re: Miniature relay Suppressor
OK, many thanks
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