Video: An Introduction to Linear AC-DC Power Supplies - Page 1
Forum section: electronics / beginners

author: TimNJ
author_rank: Super Contributor
timestamp: January 01, 2014, 01:18:16 am
content: Hey everyone,This is a presentation that I did for my high school electronics class last year. I never got around to voicing it over...but I finally did, and this is the result.It's really quite long so I'll put a table of contents in it soon so people can skip around...Anyway pretty basic stuff...1/4/14 Here's the final version:

author: ablacon64
author_rank: Frequent Contributor
timestamp: January 01, 2014, 06:52:30 pm
content: The video was removed...

author: TimNJ
author_rank: Super Contributor
timestamp: January 01, 2014, 09:13:41 pm
content: Apologies. I didn't even think I posted this! There was a video/audio sync error that I'm sorting out.

author: TimNJ
author_rank: Super Contributor
timestamp: January 01, 2014, 11:00:20 pm
content: EDIT: Video is offline again to anyone wondering...Audio problems grrrr

author: TimNJ
author_rank: Super Contributor
timestamp: January 02, 2014, 05:46:58 am
content: Woo! Finally fixed all the problems

author: Rerouter
author_rank: Super Contributor
timestamp: January 02, 2014, 05:59:41 am
content: All in all good video, though i do agree the end bit with the switch-mode image was a bit of an extreme examplecrack open a 5V phone charger and you can see just how few parts can be used at the other extreme(though i should note these circuits are not normally safe or very accurate)for those reading, a switch-mode can be something a beginner can approach after building a linear or 2, picking a chip with a built in switching element makes things a lot easier, just following the few calculations in the datasheet to work out the sizes, such as the inductor and feedback network (higher frequency ones can need a capacitor in the feedback loop to "shift the phase")

author: TimNJ
author_rank: Super Contributor
timestamp: January 02, 2014, 04:58:37 pm
content: Rerouter thanks for the comments. I guess I wanted to make a point, though I probably could have found a more typical example, say with an MC34063 or something.After watching some of it, I realize I got a little sloppy with my wording, but hopefully its understandable.

author: codeboy2k
author_rank: Super Contributor
timestamp: January 03, 2014, 11:57:36 pm
content: Yes, well done video. I especially liked the summary block diagram of the linear supply with the waveforms underneath, I think it was around the 51min mark or soYou could just edit out the switchmode stuff, you didn't do that topic any justice by giving it 5 minutes at the end. Perhaps just mention the other kind and point to your next (longer) video dedicated to switchersHow did you do the graphics? for example, the first graphic of the AC waveform with the trace moving slowly (slow reveal) .. and the transformer windings for primary/secondary ? I would like to know an easy to use graphic tool that lets me do that quickly, without animating and rendering each frame individually.

author: dentaku
author_rank: Frequent Contributor
timestamp: January 04, 2014, 02:04:08 am
content: That was better than I was expecting. I watched the whole thing because I'm still a beginner.

author: Dave
author_rank: Super Contributor
timestamp: January 04, 2014, 02:31:34 am
content: Great video!However, you mixed up the inputs of the opamp. - (minus) is the inverting one, + (plus) is the non-inverting. Maybe you could add a YouTube annotation to correct the mistake.

author: TimNJ
author_rank: Super Contributor
timestamp: January 04, 2014, 03:44:54 am
content: Quote from: Dave on January 04, 2014, 02:31:34 amWow did I really?....I'm almost about to re-upload the thing and fix it...but that might be overkill.

author: dentaku
author_rank: Frequent Contributor
timestamp: January 04, 2014, 03:51:37 am
content: Quote from: TimNJ on January 04, 2014, 03:44:54 amYup, you got it wrong the first time but named them correctly the rest of the times.

author: Dave
author_rank: Super Contributor
timestamp: January 04, 2014, 03:56:38 am
content: Quote from: TimNJ on January 04, 2014, 03:44:54 amYep, sorry.Quote from: dentaku on January 04, 2014, 03:51:37 amNope. He got it wrong every time.

author: TimNJ
author_rank: Super Contributor
timestamp: January 04, 2014, 03:57:15 am
content: Quote from: codeboy2k on January 03, 2014, 11:57:36 pmYeah I should've given switchmode power supplies a little more spotlight.The graphics were all done in...Powerpoint! For the oscilloscope waveforms I just drew the whole wave with a curvy line tool and then did an sweep right entrance animation and it just revealed it from left to right.The transformer was done in the same way, except I just set the timing to a higher speed and made each "wire" enter "after previous".Thanks.

author: TimNJ
author_rank: Super Contributor
timestamp: January 04, 2014, 03:58:04 am
content: Quote from: dentaku on January 04, 2014, 02:04:08 amThank you!

author: TimNJ
author_rank: Super Contributor
timestamp: January 04, 2014, 03:59:07 am
content: Quote from: Dave on January 04, 2014, 03:56:38 amShucks I'm going on a trip to New Orleans for the next week....maybe I'll try to bang it out before I go to bed...

author: Dave
author_rank: Super Contributor
timestamp: January 04, 2014, 04:01:51 am
content: Let me guess... Mild case of OCD? I know just how you feel, mate.

author: TimNJ
author_rank: Super Contributor
timestamp: January 04, 2014, 04:02:05 am
content: If I'm going to reupload...should I leave out the whole comparison of linear vs switching?

author: TimNJ
author_rank: Super Contributor
timestamp: January 04, 2014, 04:02:44 am
content: Quote from: Dave on January 04, 2014, 04:01:51 amI'm not sure, but I wouldn't doubt it.

author: TimNJ
author_rank: Super Contributor
timestamp: January 04, 2014, 05:06:02 am
content: New video will be here when it goes online:Thanks for the pointers. Hopefully this is the last time I upload this video!

author: Dave
author_rank: Super Contributor
timestamp: January 04, 2014, 05:15:14 pm
content: Looks good now.I like the clarity of the audio. What recording equipment do you use?

author: TimNJ
author_rank: Super Contributor
timestamp: January 04, 2014, 08:42:54 pm
content: Hey Dave. I use a Blue Snowball mic and a pop filter. Its got a built in ADC and it runs off USB so its plug and play.

author: filip_cro
author_rank: Regular Contributor
timestamp: January 04, 2014, 10:45:04 pm
content: Ok now make video about advanced power supply with feedback trough opto-coupler and chopper transformer. I didn't learn about those in high school but I want to know more

author: Abstr7ct
author_rank: Regular Contributor
timestamp: January 04, 2014, 10:50:05 pm
content: May I ask what software you used to create the slides?

author: TimNJ
author_rank: Super Contributor
timestamp: January 04, 2014, 11:07:31 pm
content: Filip,Yikes! I'm only a freshman engineering student haha. I do know a bit about that actually...but as far as being able to teach it, I'm not so sure.

author: TimNJ
author_rank: Super Contributor
timestamp: January 04, 2014, 11:09:31 pm
content: Quote from: Abstr7ct on January 04, 2014, 10:50:05 pmPlain old PowerPoint.