Why is gate drive transformer numbered clockwise? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: February 02, 2024, 07:01:10 pm
content: Hi,Do you know why this is numbered clockwise?https://www.mouser.co.uk/datasheet/2/447/datasheet_p883_1644367525-2903056.pdf

author: TimFox
author_rank: Super Contributor
timestamp: February 02, 2024, 07:29:40 pm
content: It depends on how you look at it …

author: MarkT
author_rank: Frequent Contributor
timestamp: February 02, 2024, 07:39:03 pm
content: Because the datasheet says so, simple as.

author: TimFox
author_rank: Super Contributor
timestamp: February 02, 2024, 10:25:24 pm
content: A bit of history relevant to IC packages, but not necessarily to transformers.The pin numbers for vacuum tubes were always numbered clockwise from the bottom, since the wires were connected to a socket on the opposite side of the mounting plate, and the voltages were probed from that side.This convention persisted for DIP ICs and other semiconductors, even though they are usually visualized and probed from the top, where the pin numbering is therefore counter-clockwise.

author: jonpaul
author_rank: Super Contributor
timestamp: February 02, 2024, 11:32:30 pm
content: these predate ICs, SCR, thyratron, IGBT pulse trsf.There is really no std on the trsf footprint, some bobbins origianted in Japan,Jon

author: Bud
author_rank: Super Contributor
timestamp: February 02, 2024, 11:56:41 pm
content: Minicircuits has a part with a dot marking the last pin, not first pin.

author: langwadt
author_rank: Super Contributor
timestamp: February 03, 2024, 12:03:46 am
content: Quote from: Bud on February 02, 2024, 11:56:41 pmI remember a USB controller something like a qfp with pin one in the middle of a side instead of the corner, same IC in a tsop had normal numbering, so using the same symbol and just changing the footprint to a qfp with normal pinnumbering would mean all the pin were of by half a side ...

author: MarkT
author_rank: Frequent Contributor
timestamp: February 03, 2024, 09:39:37 am
content: I think it just comes down to the simple rule - always read the datasheet and assume nothing.

author: tggzzz
author_rank: Super Contributor
timestamp: February 12, 2024, 04:19:35 pm
content: Quote from: MarkT on February 03, 2024, 09:39:37 amReadand understandthe datasheet/manual. And also read and understand what itdoesn'tsay.Some people (nonamesmonikers, no pack drill) will find that task impractical

author: newto
author_rank: Regular Contributor
timestamp: February 15, 2024, 04:00:30 pm
content: Quote from: tggzzz on February 12, 2024, 04:19:35 pmThe understanding is very important. Currently working on a replacement for a product that was designed in the 90s by people that just copied the example circuits out the datasheets with no real understanding on how they worked. It's a miracle the whole thing *did* work, but it's finicky to get working and adjust, and if you ever let the super capacitor attached to the RTC drain, you need to do a mystical ritual of button pressing, cable removal, and battery replacement to get the thing to boot again. And why did it have a supercap on the RTC in the 90s? Because the button cell they originally designed for it would mysteriously drain over a few weeks, so they just copied the supercap example from the datasheet and bodged it on with a daughter board, and never tried to figure out the actual problem.