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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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6th Aug 2019, 8:14 pm | #1 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,195
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NTC
Hi Folks, has anyone information on a Siemens Matsushita inrush limiter type S10 (or 510)
K300. It was used for inrush limiting on a battery charger for a floor sweeper (conventional transformer type) Thanks, Ed |
6th Aug 2019, 8:35 pm | #2 |
Dekatron
Join Date: Jun 2009
Location: Staffordshire Moorlands, UK.
Posts: 5,273
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Re: NTC
hi ed, I think that's a varistor
300V AC RMS, 385V DC
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Kevin Last edited by McMurdo; 6th Aug 2019 at 8:36 pm. Reason: added brief spec |
6th Aug 2019, 9:30 pm | #3 |
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Location: Newcastle upon Tyne, Tyne & Wear, UK.
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Re: NTC
Hi Kevin, I thought that at first, but it in series with the incoming supply and when linked out it allows things to power up.
The surprising thing is that it does not look as if it has seen any heat and measures o/c on a DVM. Ed |
6th Aug 2019, 9:39 pm | #4 |
Dekatron
Join Date: Jun 2009
Location: Staffordshire Moorlands, UK.
Posts: 5,273
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Re: NTC
If it looks like the one below, it's definitely a varistor, the S10 means 10mm disc and the K300 means rated for up to 300V AC.
Epcos (siemens/TDK) varistors are invariably blue with the short part number marked in white, and the NTC thermistors are invariably black (or formerly grey in the Siemens & Halske days) and are usually marked NTC..and the cold resistance value.
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Kevin |
6th Aug 2019, 11:28 pm | #5 |
Dekatron
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Location: Surrey, UK.
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Re: NTC
Do you know of any "recent history" of this charger Ed- is it possible that someone else has previously had a go, say mis-wiring the mains input side when replacing a damaged supply cable and putting it aside when it failed to work? I agree with Kevin that it sounds very much like a Siemens MOV code as applied to these shiny blue disc devices, rather than the matt black finish NTCs,
Colin |
6th Aug 2019, 11:30 pm | #6 |
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Re: NTC
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7th Aug 2019, 9:06 am | #7 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,195
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Re: NTC
Hi Gents, thanks for the info, I agree it looks very like a varistor.
The charger is for a floor scrubber and appears to have been faulty for months. There does not appear to have been any changes/ replacements on the PCB at all, but I'll try and draw the circuit to see what goes where. From memory it was in circuit with a mains switching relay which then fed the (conventional) transformer. The joys of faultfinding when there is no documentation, no money and people are now used to throwing away the information! Ed |