[Closed] I need a suggestion for alternative parts [Unresolved] - Page 1
Forum section: electronics / beginners

author: emerald
author_rank: Newbie
timestamp: August 17, 2020, 02:15:04 pm
content: Parts for a 220 V LED security light with PIR (the number on the circuit board is ZF – L3291)1: I need a suggestion for an alternative to the fusible resistor that is blown to smithereens.I have Very limited info…The size is approximately 1 cm x 2 mmthere is very little left of the outside of the resistor, but from what I can see…Possibly green backgroundand evidence of a blue band2: a linear LED driver chip (JW 1691H)I need a replacement/alternative for the above, which seems to be a Joulwatt product.

author: perieanuo
author_rank: Frequent Contributor
timestamp: August 17, 2020, 03:35:31 pm
content: I had some LED bulb made with BP5131D, maybe it's the same current regulator?Try to read the chip marking, then the datasheet tells you which resistor you need, in my case the resistor was a 24R9 one, for aprox 24mA LED current.I see you found the chip, just put down the schematic and in datasheet you have resistor examples for 25mA and calculation formula also:"The LED current can be adjusted by changing the current sensing resistor ofJW1691H. For example：Setting the LED current to 30mA, the current sensingresistor is:Rs≈2000*0.5V/0.03mA*0.89=30KΩ, then R3=3 KΩ, R2=27 KΩ"regards,pierre

author: emerald
author_rank: Newbie
timestamp: August 17, 2020, 04:30:56 pm
content: Thanks Pierrethe only datasheet I found had zero information in it,https://www.joulwatt.com/Upload/file/201812/20181219212201_8437.pdfThank you for the example calculations, but I don't really understand them. That's the reason I'm posting in the beginner's Forum, but I appreciate your efforts anyway.FYI, on my board (photo above) R4 is reading 31.6 K. R5 appears to be empty (but it still reading about four megs.In a perfect world, I'm looking for someone to say you need chip xxxx, Which I can then go and purchase.Failing that, if I don't get a solution in the next couple of days I may buy one of your BP 5131D's, and hope that it works.John

author: Jwillis
author_rank: Super Contributor
timestamp: August 18, 2020, 03:34:00 am
content: 6.8 Ohm 1/2Watt Flame Proof, Fusible, Safety resistor.https://www.digikey.ca/en/products/detail/vishay-bc-components/NFR25H0006808JR500/614146for exampleR4 sets the output current .You need to ask why the fusible resistor and chip failed. What were the circumstances that caused the failure. There may be other problems that are not apparent upon visual inspection.Does the power supply have an over voltage or is there a current draw that placed the resistor beyond it's power rating of 1/2 watt?

author: perieanuo
author_rank: Frequent Contributor
timestamp: August 18, 2020, 07:30:32 am
content: see here schematic and all:https://www.joulwatt.com/Upload/file/201901/20190116174446_7812.pdfI attached it for you.so you have schematic diagram and that simple calculation example I quoted before.or just test with the resistor value in datasheet's example schematicbut I guess the control IC is dead, that's why I proposed before you take a look at another chip, you can make another schematic with whenever IC you can easily get/buy.regards,pierreps:look here in Uk simpliest IC for 220V:https://uk.farnell.com/microchip/cl220k4-g/simple-220v-20ma-temperature-compensa/dp/2448486?st=cl220£0.898 1,991 In stockthen you may replace yours with this cl220; just add a mono-alternance rectifier with some electrolytic capacitor, the cl220 is for DCsorry this cl220 won't work, the rectified voltageis greater than cl220 may take.I'll have to look into another simple solution, but one of the simpliest is the one I pointed before with the BP5131D ICI remember also some current regulators from phillips I think are also simple, they look like smd diodes in series with your led line, but those I saw were 30mA (from memory)You can look for an IC like this BP5131D is the simpliest way for your case, 3 legs and 2-3 resistors with a rectifier bridge.regards

author: perieanuo
author_rank: Frequent Contributor
timestamp: August 18, 2020, 08:10:18 am
content: hi,I found onehttps://www.tme.eu/gb/details/ixcp10m45s/integrated-circuits-others/ixys/IXCP10M45S from IXYSjust add the 220V bridge rectifier with some 5.6-10 uF/400V electrolityc capacitor after the bridge and it will workthis IC take 900V, so you're covered

author: emerald
author_rank: Newbie
timestamp: August 18, 2020, 10:46:49 am
content: QuotePierremaybe I'm just getting too old (72), but I can't seem to locate BP5131D anywhere. (Other than Ali express – and I don't really want to have to wait a month)John

author: emerald
author_rank: Newbie
timestamp: August 21, 2020, 01:48:19 pm
content: After many hours googling, would this be a suitable replacement for the LED current regulator?https://www.mouser.com/datasheet/2/115/AL5890-1274651.pdfI'm determined to get this working by hook, or by crook eventually