Nice video tutorial on Switching Regulator Power Supplies

[nixxon]

Really nice 72 minute video on Switching Regulator Power Supplies by Randy Fromm (1992)



First theory and then practical classroom walkthrough.

Enjoy!

[McMonster]

Somewhere around 6:30 the guy said that they only use two diodes of a bridge rectifier in the US at 115 V, but in Europe we use all four diodes. What?

EDIT:
Other than the above confusing (me at least) statement absolutely no schematic diagrams shown. But a nice video in general.

[M0BSW]

 I noticed the big capacitor closet to use is bulging at the top ,ready to pop.

[McMonster]

Only half the bridge is used for a switched doubler. This is the little switch on the back of some units that switch between 115V or 230V. When its set to 115V it is doubled to 230V.

Thanks, I thought he was only refering to getting DC out of AC. It's clear now.

[M0BSW]

Seems like a really good teacher , not like some I've met who are up their own jacksy

[tom66]

Only one thing about the slipping label, not a big deal, just depends on how the cap is made, I've seen plenty that aren't failed.

[Astroplio]

Thanks for sharing this video, I absolutely loved it. He is great, I subscribed to his channel, there are a couple of other videos there that interest me.

One thing that surprised me was that 20 years ago he managed to use a camera to follow him around (face tracking working back then??), and teach at the same time; that's a talent on its own right there man, awesome!

On a second note, how much of this troubleshooting has been changed today, 20 years later? Any of you with more experience repairing switching regulator supplies can confirm that all/some of this are still valid?

George

[tom66]

One thing that surprised me was that 20 years ago he managed to use a camera to follow him around (face tracking working back then??), and teach at the same time; that's a talent on its own right there man, awesome!

I thought he had a cameraman! Hence the copyright notice at the beginning...

On a second note, how much of this troubleshooting has been changed today, 20 years later? Any of you with more experience repairing switching regulator supplies can confirm that all/some of this are still valid?

The majority of it still applies. For example the voltage doubler circuit is still used in low cost power supplies.

[Astroplio]

I thought he had a cameraman! Hence the copyright notice at the beginning...

I don't know really, it is confusing because he is using the remote joystick to zoom in-out and pan-tilt the camera! (PTZ camera with auto tracking?)

Nice, thanks!

[dr_p]

The camera is tracking his fancy remote/microphone.  O0 Very nice video, very good teacher.  He doesn't go into many details, just what you need to do. That is good for beginners because it doesn't confuse them with technical explanations and encourages them not to give up. And it's also good for experienced people, because it tells you the straight problems, you should be able to fill in the gaps.

Note that he is talking about NPN power transistors, but nowadays most of switch mode power supplies use MOSFETs. Almost all MOSFETs have the protection diode included. Sometimes it's shown in their symbol, sometimes it's omitted, but it IS there and the same principle applies.

What is interesting is how permissive safety standards were. Not a word about discharging caps or any other precaution.

 If you are interested in troubleshooting a SMPS, you should definitely check this tutorial too. It's a way longer reading material, but a lot more detailed.

[yashrk]

This video is private  cannot see it

[Red Squirrel]

This video is private  cannot see it

Yep I get the same. 

[SteveyG]

This video is private  cannot see it

Look at the dates, this is from years ago.