I love this attention to detail ! (Though you could speed it up a tad, you know...) Tho' a plain desktop power-supply is a bit unworthy of your attentions, sir, because most times the job will get done anyway. Not to say that design sloppiness is OK, but the applications will usually condone it. However, I have a suggestion : Please take up a more critical gadgets such as 1) UPS 2) DC Welding-Inverter 3) AC TIG Welding Inverter wherein your attention to detail will make a difference of working or dead gadget, which is satisfying ! As I said before, we would end up with useful gadgets as well as an education this way.

@KissAnalog

5 жыл бұрын

I like that idea - thank you for this input!!

@sammixon1207

4 жыл бұрын

@@KissAnalog i think your speed is fine

Old vid but good material. I missed the relationship between Fuse & Thermistor preceding Filter Caps. Thanks for posting.

Great stuff again thanks!

@KissAnalog

4 жыл бұрын

Thanks Adam - I appreciate you!

Eddie...I am lovin' your power supply series!

@KissAnalog

3 жыл бұрын

That's great Steve! I'll have plenty more. I have an SMPS design (AC/DC for audio amps) that I want to do very soon.

Nice info, thanks :)

@KissAnalog

3 жыл бұрын

You bet! Thanks for the feedback!

If I’m running 220v ac to use a thermistor do you need to hook only 1 thermistor to one side of the hot line? Or do you need to hook to one to each hot line being 220v? It’s hard to find any info on this topic.

@KissAnalog

4 жыл бұрын

Great question! No, it is still a series circuit, but the current will be higher with the higher voltage so the thermistor needs to be rated for that current. Thanks for asking.

Great and clear info! What if we used a 1,000V 1A in a circuit using 1.5V 1.5A, would the fuse still blow? I mean, there are a lot difference in power between 1,000W and 2.25W.

I was wondering replacing a slow blow fuse for two fast blow in parallel not sure the formula for this, would it be half the current rating of the slow blow for each fast blow fuse?

@KissAnalog

3 жыл бұрын

I wouldn't recommend using 2 fuses in parallel. They will not share perfectly and then you have to compensate by making them larger current ratings, and then you lose protection. Try using a fast blow at the next higher current rating, or at the same current rating and see if it isn't slow enough;) Even fast blow fuses are slow...

Very interesting video, thanks. Looking at subsequent videos where you deal with inrush current, it’s obvious that the thermistor is providing quite some protection - IIRC, it drops the current from around 68A to 12A. I assume that the rating of the fuse you would use is based on that value? More generically, having calculated the thermistor to use and its operating characteristic, you determine an appropriate fuse? I further assume that the downstream current that the load can draw also plays a part - does the thermistor play a limiting role across the whole circuit in terms of current that can be supplied (I may have confused myself totally here!!)? I liked the way you went through the data sheets - I find them really hard - and it would be useful to have some worked examples for choosing the fuse and thermistor in relation to the power supply characteristics being designed for, including taking account of tolerances (for example, that thermistor you chose has a tolerance of +/- 20% so you’re somewhere between 8Ohms and 12Ohms.). Really informative video, thanks

@KissAnalog

5 жыл бұрын

Thank you for watching and for the great suggestions! You are right on point. I’m working on the follow up videos now and should post later today and tomorrow.

do these NTC fail over time or should they last forever unless damaged by the power?

@KissAnalog

2 жыл бұрын

Great question! I do think the NTC, if not overly stressed, should last very long without any issue. They are used in many power supplies without issue.

@ukspawn666

2 жыл бұрын

@@KissAnalog the reason I ask is my dac PSU is tick tick ticking and I hear its because a cap that charges it failed... but I'm a total noob so just checking things. Any ideas on that? It's not ticking now that's gone but the unit still won't power on

@KissAnalog

2 жыл бұрын

Capacitors are a common failure point. Any cap that shows any bulging should obviously be replaced. If aluminium electrolytic capacitors were used in the signal path, then these should be swapped out with poly caps.

@ukspawn666

2 жыл бұрын

@@KissAnalog thanks

Pen and Paper

@KissAnalog

4 жыл бұрын

Thanks for the feedback! ;)