I wish I could make them full time, but I can't. So I'm shooting for one a month or at least more than one a quarter.

+codedemonelectronics Appreciate you being honest. ;) (Seriously, thanks.)

Hello Poland! Thanks for watching.

By the way, if I put a 0.47uF capacitor in the input (instead of .33uF, as manafucter says) there is no problem, right? :) Thanks

anything less than 10 uF is fine.

+script0r inside Thank you.

this was a perfect video with zero unusefull time . yes there must be sick haters everywhere .

@@tolgadabbagh1877 "Sick haters" That's quite an extreme view of someone who just pressed a button that was made for pressing.

Because our other videos aren't high quality?! Just kidding. Thanks for the feedback.

+Victor P. Yeah, I'd love to post videos faster. But as a one-man education and production shop, this is about as fast as I can go.

+Justin Young Hey Justin! I'm counting from when I was 11 or 12. Not only did I have hair back when I knew you, it was always a total mess!

Ceramic capacitors are lower ESR and come in smaller values. They are better for high-frequency decoupling/filtering. Electrolytics come in larger values, but also have higher ESR. They are good for low-frequency or (bulk) decoupling.

I think anything over 450°C is safe to say, you need a heat sink. ;)

Thanks, should I have more questions I know who to ask. LOL.

yes

Thanks

"Electricity" does not flow. "Electricity" is a construct. Current flows when a Voltage is applied. In the case of a linear regulator the current into it is equal to the current out of it (minus some tiny loss.) The regulator, effectively, changes the voltage dropped across itself to maintain the required output voltage. So heat disspiated is equal to the voltage drop across the regulator times the current through it. A regulator that switches "on and off" is a switching regulator.

It is 2V above the output voltage.

Large electrolytic respond to slow changes while smaller ceramics respond to faster changes.

If you forget the capacitor in your design, you can still solder at least ceramic smd chips between the tht leads of the to220 package.

Without a smoothing capacitor and a regulator, you won’t have DC.

+Chetan Amrao I converted to nF. 0.33uF is 330nF.

okay i didn't notice that! LOL

For low-frequency or bulk decoupling they work fine. But you'll want to put a low-value ceramic in parallel with it for higher frequency noise. While called a decoupling or bypass capacitor, the ceramic is really a filter cap in that case. The caveat here is if you use polymer aluminum (or polymer tantalum) capacitors instead of traditional wet aluminum electrolytics. Polymers have significantly lower ESR.

The point of the regulator is to provide a stable voltage regardless if the input voltage changes or if the load's current draw changes. If the load's current draw changes, ohm's law would suggest its voltage drop changes, so the regulator must adjust its output to maintain a stable output. As for difference "variable resistor and a potentiometer". In practice, nothing. By definition a variable resistor would only have two terminals. A potentiometer a 3 terminal devices that forms a voltage divider on its own

now i understand better , I was wrong about one point, Thanks so much

+majdinj I think you mean "decoupling", not "coupling." They are definitely not coupling capacitors. The language I used was very intentional. "Decoupling", "filtering", and "bypass" are often used mis-used or interchanged. In a linear regulator both capacitors are there for decoupling. Since there is no switching noise generated inside of the regulator, their primary function is to decouple, not to filter. The input capacitor decouples the regulator from the supply. The output capacitor decouples the regulator from the load. Switching regulators, the capacitor's functions a very different. In that case the input is generally decoupling capacitor while the output is there for filtering.

+AddOhms Oh thanks man.

You. cannot. Series makes no sense and parallel they would try to regulate each other.

+Power Max Another issue with large capacitors on the output is when the regulator first turns on, the initial inrush current of that large capacitance can cause the regulator to go into thermal shutdown. So you end up with a linear regulator which a huge oscillation, while trying to charge up the output capacitor--the same cap that was put there to help it!

AddOhms Yikes! I do notice that when I attempt to design a opamp based LDO from scratch in LTspice, if I use ideal capacitors (ESR

AddOhms Something that I hope to do is to design my own accurate, arduino controlled lab power supply. One that will be at least 0-15V with 2 isolated channels, at at least 0-5A, which will allow full voltage and current range adjustment. That is proving to be a challenge with things like power dissipation, loop stability, transformer / preregulator stages, dropout voltage of the pass transistor element, etc. It is all getting quite complex! I have a dual-rail design in LTspice that seems to work well, I can give you a link to my old instructables question about it.

+Power Max For the longest time I wanted to design my own: power supply and oscilloscope. Eventually I bought them instead. Both are going to be "someday" projects for me.

Resistance. Junction (to) Ambient. What's the thermal resistance between the junction (the silicon) and outside air.

You would probably need a switching regulator.

That's what most designs do. The bulk electrolytic cap is *decoupling* the circuit from the power supply. Hence the name, "decoupling capacitor."

As long they each step down the voltage by least 2 volts, yes. The dissipated power would be spread across them.

Regulators usually have a minimum load specification. It's the minimum current they need to regulate the output. If there is no load, there is nothing for the regulator to, well, regulate. If you're using a LM7805, it's minimum load is probably 5 milliamps. Add a 1 kohm resistor for testing.

+MrLookslikeMani Hi Germany! Yeah 100-470uF get used pretty often. I just want to make the point they aren't always necessary. If you go with much larger values than 470uF, you may actually cause the regulator to oscillate when it first powers-on. Capacitors are a short circuit when they first start to charge. So too much capacitance can cause too much current, activating the thermal shutdown. Looking back, I should have added that in this video. I may make a separate one to explain better.

+AddOhms Thanks a lot. :)

My $0.02 - I've been using 10 mF caps for these for years. Never had a problem. I had always assumed that this was the norm.

Yes, but you shouldn't. A decouple capacitor DECOUPLES a device from the power supply. So you should place the larger capacitor close to your load, not the regulator.

+TheProCactus Nope

Would it be something relevant to you?

No. I'm not an electrician and I don't know electrical codes well enough to talk about them.

Well thanks for your thought, I look forward to watching more of your videos.

You probably want a switching regulator. Or at the very least, an LDO with an enable pin. Either way, not a circuit I can help with.

They are decoupling capacitors, which are different from "coupling." I explain why starting at 4:52. Yes, all grounds must be the same. Ground is a reference point.

It helps but does not eliminate it. It’s just a positive thermal coefficient.

@@AddOhms How protective is that action - thermal runaway usually happens so quickly - how would I calculate a safe margin?

It's not something I would ever have a design that relies on [for a linear regulator.] If it is "thermally running away" there is a serious problem in the design.

+Shawnak Sawaikar Google “fairchild lm7805”

ok

Yes! That is the point of a regulator. If is constantly changing between 7 and 9 volts, you might need to add some more capacitance on the input to help smooth it out. Watch the output to see how much it varies, if at all.

+Matt Hunter You can't just wire regulators in parallel with each other. They will attempt to regulate each other. There are techniques to isolate them, but generally that's not efficient. The best approach is to get a single supply that sufficient for the load. This could mean, splitting the load up. Example, half the LEDs on one and the other half on the other.

Ah, I see. They will be in pairs, might it be ok to have one regulator at each pair of lights? (11W total with the regulator supplying 12v at 1A) That way the main wiring is unregulated but each module is safe

If yes How can it be achieved.

With an external circuit yes. Do a search for "LM317 Current Limiter."

Thankyou sir Got the idea :-)

I don't know what you mean by "what you are doing". I have an Electrical Engineering degree.

Overall you're okay. 220uF on the input is fine. You're decoupling the regulator from the rest of the circuit. 220uF directly on the output might be a bit high. On an older linear like the 7805, it'll be fine. But it's better to put a small capacitance (1-10uF) on the output for filtering while putting the big caps near large loads, like a motor or LED strip.

Voltage regulators actively (and accurately) regulate voltage. Zeners are passive, so they drift under various conditions. Watch: Voltage Dividers as Regulators ?! | AO #22 kzfaq.info/get/bejne/Y9F1m5OFvtC9iXk.html

these days I have been studying converters and regulators, like buck and boost, and I do not understand what the output current depends on

+Mohannad SMARTHERO The load determine the current drawn. The regulator's inductor and capacitor determine the current it can provide.

almost clear enough, I still need to make some tests, thanks alot

shubham raj aonkimonki YESS! To start, your ripple frequency are almost some 100MHz so you objectif is to pass only the DC! Well that’s great bc DC’s frequencies are almost nul in simple terms you have to find the stability, then you know that the formula that gives the capacitance impedance is: 1/(2pi*f*C) otherwise when f=0(DC) the impedance is like too too high so current can’t flow through the capacitor and if f= almost 100MHz then you’ll find your 330nF ( behind that a complicated maths and a big knowledge of impedance at different frequency)

Measure the input and output voltage with a multimeter, while there is a load on the regulator. Unloaded regulators, like batteries, may not output the right voltage.