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Challenge of the Day: from halogen transformer to battery charger

Started by Unknown May 3, 2018
On Monday, May 14, 2018 at 10:52:14 PM UTC-4, tabb...@gmail.com wrote:
> On Tuesday, 15 May 2018 00:14:41 UTC+1, gnuarm.del...@gmail.com wrote: > > On Saturday, May 12, 2018 at 9:39:41 PM UTC-4, k...@notreal.com wrote: > > > On Sat, 12 May 2018 16:59:17 -0700 (PDT), > > > gnuarm.deletethisbit@gmail.com wrote: > > > >On Saturday, May 12, 2018 at 7:13:49 PM UTC-4, pcdh...@gmail.com wrote: > > > >>NT: > > > > >> >I just assumed we all knew the usual circuit diagram abbreviations, D, Tr, Q, BR etc > > > >> > > > >> I don't recall seeing Tr or BR as a ref des. > > > > > > > >I don't think I've ever really called them rectifiers other than that ones in my truck alternator. The bridge I just notate as D. It's drawn on the schematic as a diode bridge, so why add a special ref des especially a two letter one? I don't think I've ever used a two letter ref des. > > > > > > 'CR' is a pretty common RefDes for a diode. We use 'IC', 'RA', and > > > 'CN' for ICs, resistor arrays, and connectors. Those come to mind > > > immediately and I'm sure there are others. > > > > I think U is much more common for ICs, R is adequate for resistor arrays (much as D is adequate for diode bridges) and J is the typical designator for connectors. Why buck convention? > > there are many conventions to choose from. > And some EEs prefer to be mildly humorous with descriptors like CR. > > J is also much used for jumper or link btw.
Ok, to each his own. I don't recall ever seeing CN on a schematic. I have seen J and P used for jack and plug, but as others have indicated, the terms jack and plug are not so clear with some connector types. In many cases I've seen J used on all connectors, so I now just use J. I also don't recall ever seeing IC used for devices. One place where I have seen variations is both X and Y used for crystals. I can't recall any other variations in the standard designators, but there may have been some. As others have mentioned, it is not uncommon for boards to be crowded so that two letter ref des would need space that might not be available. I know the stuff I design is often *very* crowded. In one case I had to put the ref des over top of vias and had to deal with the PWB fabricators wanting to clip excessively around them. We discussed the concerns and I got them to only clip close to the hole and not around the entire pad making the ref des legible again. Rick C.
On Monday, May 14, 2018 at 10:52:14 PM UTC-4, tabb...@gmail.com wrote:
> On Tuesday, 15 May 2018 00:14:41 UTC+1, gnuarm.del...@gmail.com wrote: > > On Saturday, May 12, 2018 at 9:39:41 PM UTC-4, k...@notreal.com wrote: > > > On Sat, 12 May 2018 16:59:17 -0700 (PDT), > > > gnuarm.deletethisbit@gmail.com wrote: > > > >On Saturday, May 12, 2018 at 7:13:49 PM UTC-4, pcdh...@gmail.com wrote: > > > >>NT: > > > > >> >I just assumed we all knew the usual circuit diagram abbreviations, D, Tr, Q, BR etc > > > >> > > > >> I don't recall seeing Tr or BR as a ref des. > > > > > > > >I don't think I've ever really called them rectifiers other than that ones in my truck alternator. The bridge I just notate as D. It's drawn on the schematic as a diode bridge, so why add a special ref des especially a two letter one? I don't think I've ever used a two letter ref des. > > > > > > 'CR' is a pretty common RefDes for a diode. We use 'IC', 'RA', and > > > 'CN' for ICs, resistor arrays, and connectors. Those come to mind > > > immediately and I'm sure there are others. > > > > I think U is much more common for ICs, R is adequate for resistor arrays (much as D is adequate for diode bridges) and J is the typical designator for connectors. Why buck convention? > > there are many conventions to choose from. > And some EEs prefer to be mildly humorous with descriptors like CR. > > J is also much used for jumper or link btw.
Oh yeah, I use R for jumper because that's what they are, zero ohm resistors. Rick C.
On 05/14/18 22:52, tabbypurr@gmail.com wrote:
> On Tuesday, 15 May 2018 00:14:41 UTC+1, gnuarm.del...@gmail.com wrote: >> On Saturday, May 12, 2018 at 9:39:41 PM UTC-4, k...@notreal.com wrote: >>> On Sat, 12 May 2018 16:59:17 -0700 (PDT), >>> gnuarm.deletethisbit@gmail.com wrote: >>>> On Saturday, May 12, 2018 at 7:13:49 PM UTC-4, pcdh...@gmail.com wrote: >>>>> NT: > >>>>>> I just assumed we all knew the usual circuit diagram abbreviations, D, Tr, Q, BR etc >>>>> >>>>> I don't recall seeing Tr or BR as a ref des. >>>> >>>> I don't think I've ever really called them rectifiers other than that ones in my truck alternator. The bridge I just notate as D. It's drawn on the schematic as a diode bridge, so why add a special ref des especially a two letter one? I don't think I've ever used a two letter ref des. >>> >>> 'CR' is a pretty common RefDes for a diode. We use 'IC', 'RA', and >>> 'CN' for ICs, resistor arrays, and connectors. Those come to mind >>> immediately and I'm sure there are others. >> >> I think U is much more common for ICs, R is adequate for resistor arrays (much as D is adequate for diode bridges) and J is the typical designator for connectors. Why buck convention? > > there are many conventions to choose from. > And some EEs prefer to be mildly humorous with descriptors like CR. > > J is also much used for jumper or link btw.
I use 'R' for allegedly-zero-ohm resistors. "JP" for jumper pins is about the only two-letter ref des I've ever used, iirc, and that's about one board in ten. Connectors are generally pretty big, so the silkscreen space required by 'CN' is a nit, but 'RA' and 'IC' are a bit more of an issue. It's a matter of taste. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
On 5/14/2018 9:52 PM, tabbypurr@gmail.com wrote:
> On Tuesday, 15 May 2018 00:14:41 UTC+1, gnuarm.del...@gmail.com wrote: >> On Saturday, May 12, 2018 at 9:39:41 PM UTC-4, k...@notreal.com wrote: >>> On Sat, 12 May 2018 16:59:17 -0700 (PDT), >>> gnuarm.deletethisbit@gmail.com wrote: >>>> On Saturday, May 12, 2018 at 7:13:49 PM UTC-4, pcdh...@gmail.com wrote: >>>>> NT: > >>>>>> I just assumed we all knew the usual circuit diagram abbreviations, D, Tr, Q, BR etc >>>>> >>>>> I don't recall seeing Tr or BR as a ref des. >>>> >>>> I don't think I've ever really called them rectifiers other than that ones in my truck alternator. The bridge I just notate as D. It's drawn on the schematic as a diode bridge, so why add a special ref des especially a two letter one? I don't think I've ever used a two letter ref des. >>> >>> 'CR' is a pretty common RefDes for a diode. We use 'IC', 'RA', and >>> 'CN' for ICs, resistor arrays, and connectors. Those come to mind >>> immediately and I'm sure there are others. >> >> I think U is much more common for ICs, R is adequate for resistor arrays (much as D is adequate for diode bridges) and J is the typical designator for connectors. Why buck convention? > > there are many conventions to choose from. > And some EEs prefer to be mildly humorous with descriptors like CR. > > J is also much used for jumper or link btw. > > > NT >
Maybe this will help: <https://en.wikipedia.org/wiki/Reference_designator>