Help Me Identify This Part - Page 1
Forum section: electronics / repair

author: falcom
author_rank: Contributor
timestamp: April 04, 2018, 02:01:01 am
content: I am trying to replace the part labeled T1 in the picture below. It looks like an inductor but it is not.Any help is appreciated.Dave

author: Samogon
author_rank: Frequent Contributor
timestamp: April 04, 2018, 02:40:20 am
content: Pulse transformer

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: April 04, 2018, 03:04:41 am
content: It's an array.https://www.digikey.ca/product-detail/en/bourns-inc/SRF1280-220M/SRF1280-220MCT-ND/2458614A pulse transformer would be used for signals, not surrounded by beefy power parts and traces like this.You can see a LT1763 LDO after it.

author: falcom
author_rank: Contributor
timestamp: April 04, 2018, 09:29:11 pm
content: Ok so its a dual winding inductor. Icant find the exact match. It is from about 2004.It appears to be a 10uf. The way I understand it the dual winding inductors are labeled for parallel so 100 would be 10uf in parallel.The measurements are (aprox) 6.8 mm x6.8mm x 2.3mm thickI hate to be a pain but my google searches have come up empty so far.A manufacturer would be helpful.PS Thanks Alex for putting me on the right track.

author: coromonadalix
author_rank: Super Contributor
timestamp: April 04, 2018, 09:57:09 pm
content: have you tested the coils for conductivity, why are you sure its defective ?You have an 5 pins sot23 near it, it may work like an buck boost converter or an miniature pwn psu before the lt1763 ...100a must be the coil value 100 uh ??

author: falcom
author_rank: Contributor
timestamp: April 04, 2018, 11:07:18 pm
content: The 5 pin that feeds it is a LT1930 buck boost convertor.Voltage input is 6 volts.The unknown part shows a dead short across all pins.

author: Samogon
author_rank: Frequent Contributor
timestamp: April 05, 2018, 02:03:00 am
content: It is probably not dead short, it just has really low resistance, like few mOhms. You have to measure it with LCR meter, to be sure it is still in 100uh range.

author: falcom
author_rank: Contributor
timestamp: April 05, 2018, 03:07:09 am
content: Since it has dual windings they should be electrically separated..

author: Samogon
author_rank: Frequent Contributor
timestamp: April 05, 2018, 04:25:04 am
content: Quote from: falcom on April 05, 2018, 03:07:09 amDid you desolder it? Anything can happen

author: coromonadalix
author_rank: Super Contributor
timestamp: April 05, 2018, 07:36:26 am
content: in ohms you may read a short but with frequency its an other story, we have small transformers at my job, short or almost 0 ohms but they run at 27 mhz, thats a difference .... if the pwm ic is dead, sure you'll think its short ??It may be an inductor with 4 pads too ?? test it with an lcr meter

author: falcom
author_rank: Contributor
timestamp: April 05, 2018, 03:37:06 pm
content: I think I found it.It is a coupled inductor which is 2 separate windings in the same package so no DC between the two.It is a SUMIDA CLS62-100 which Digikey and Mouser show as a standard inductor (not coupled)I found it from the LT1930 datasheet which had the exact circuit layout in their circuit examples with parts listings.Thanks again for all your help.