Laughing

I'm from UK. I'm learning a lot of awesome Aussie slang from this channel.

+Adam Harrington +EEVblog yes please! this REALLY helped me grok a few things. would love to see more like this one. Thanks for keeping this going!

same!!

It's seems hard to find proper circuit development tutorials around. This one was perfect!

ditto

This channel is solely responsible for getting me hooked on electronic circuit design

Yes, but you must consider also the operation cost. The pcb must be manufactured, the electrical components must be placed an soldered. If you are gonna place this components on a pcb which already is designed to be in your system, the influence on the operation cost for this feature is almost insignificant. Anyway, the final price tag is still below.

Well, that's the problem.. your buying off digikey haha

Try expand the calculation by comparing the pcb cost, pcb assembly and fitting vs Drilling a hole for the toggle switch, soldering leads to the switch and fitting the switch Yes - I do consider the electronic solution done with other electronics fitted anyway. As a former PTA engineer I learned to avoid any extra manual assembly cost on the production line.

You forgot to factor in 200 breadboards at $2 a piece...

As you go higher in production count the end cost may worth it, because the robot machines can populate all those parts in 3 seconds and the addition of the PCB is almost negligible. It is good alternative however.

Works great, thank you very much !!!

This works great :)Thank you :)

Anyone have a diagram for this? Is the capacitor in series with the collector of t2 or between collector and ground? Intrigued...

Jacob Kon between collector and ground

How about an explanation WHY it works ... is it as "good" as the original concerning current in OFF state ?

Absolutely agree

It may be the leakage current. I've witnessed a thyristor made of jellybean BJTs turn on by itself due to leakage.

You are right.... In reality this 4.00 circuit will be pretty unstable.... We just have to use a big resistor between the collector and base to ensure that the base of Q1 remains high enough not to turn on randomly.

Youare actually right, I tried to make the circuit at 4.00 but turned ON by itself and the ON sswitch seemed to be doing nothing at all. I will try with your suggestion again

Would I read this earlier, I would save myself some 8 hours of building and simulating... 😂 On the plus side, I am able to simulate this circuit in CircuitJS, TinkerCad AND Ltspice... 😅

Interesting the 1337 timing... like "1337" slang on Reddit. Creepy coincidence...

@@BlackXeno what doe sit mean?

@@play_sports_and_read_books en.wikipedia.org/wiki/Leet

Bob Ross of electronics

Happy little accidents.

re pt 2 - i had issues with the filter cap of the downstream circuit bleeding back through Q1 turning it back on. A 680k resistor as suggested solved this

Ernst Stavro Blofeld does she has high input impedance if you know what i mean ?^__^

marionetadelplaneta She does, but that is none of your business.

Ernst Stavro Blofeld what's so private in asking if someone is friendly?

marionetadelplaneta I signed a nondisclosure agreement.

Power Max While the NPN transistors are ON, you'll be drawing 100x more current through both of your 1K resistors than if you used 100K resistors, stressing them more. For production, you'd probably want higher reliability, thus higher resistor values.

downthetube within Well it was a simulation, I often use the 2N2222 transistor in LTspice in such a way it ends up dissipating many hundred watts. Not an issue! I often use TO220 transistors when prototyping stuff, as they are more difficult to destroy. However the disadvantage is that more base current is necessary for bias the transistor, and consequently I will end up using low value pullups for the bases. For small signal transistors and darlingtons and stuff, you are correct.

Thanks - I was just mentioning some obvious improvements as a design philosophy. Guess I'd have to look up datasheet for 2N3904 to see how much margin is left when increasing from 1K's or decreasing from 100K's. Another issue is power budget or allotment on the input power form. Of course, how one makes these compromises and reiterations in design are largely dictated by an overall product specification, implementation, schedule, budget, and all the "ilities". The video is a fun, nicely explainable circuit. cheers!

OMG I LOVE YOU, i thought i was just dumb

just add one small capacitor between emitter and base of a PNP transistor and it will work as theory describe.

If referring the circuit at 4:00, just add a 1M resistor between the emitter of PNP and the collector of NPN.

​@@dharmikbhavani7272 it works well!! thank you

...and don`t forget the Christmas illumination when you hold the switch.

You can't really be this dense.

magicponyrides What do you mean exactly?

IvanIvan1974 he means the point of this is that its cheaper to implement because it means you don't need a beefy switch and can use an elcheapo switch without blowing it up :) if you were just joking it didn't work, this is text its hard to tell so you should expect those reactions from people :)

megaspeed2v2 I don`t even know if he wrote to me. His reply is not directed to me. BTW, I use switch system like this too, I implement it a little bit in a different way but actually it`s quite similar. (without Christmas illumination)

I love that half a micro-amp is half a bees dick in Australia.

Check your math. The time constant would be a hundredth. If you go down in resistance, you'd need to go up in capacitance.

Sounds interesting! I know nothing about that kind of circuitry (sounds like logic!). Please make a video on a design concept and give us a walk through! Especially of the power-on sequence capability. Then throw a couple part numbers in there so novice people can get up and running! It'd be great!

Or just use an MCU if you already have one (very probable), a pushbutton, and a MOSFET. Problem solved for a few cents!

How are you setting the initial state of that counter after power on?

Luke Wren Also, I doubt his CMOS chip has as tiny standby current as the circuit in the video. Video circuit standby is dominated by C-E leakage in the left BJT.

@@johnfrancisdoe1563 that's true! I have one major problem with Dave's circuit though, which is its sensitivity to bleed time of the system load. Large output capacitance and small load -> 2N3904 becomes biased again and doesn't switch off. I think any circuit where you try and be clever and use system load as a switching element can have this issue. My current favourite circuit involves a latch built from a dual inverter IC, e.g. 74LVC2G04. They cost around the same as a small-signal transistor, leak around 4 uA, and give you clean switching every time. I think the lesson might be "if you want a latch, build a latch" :)

Uh. This doesn't start up in the on state. The gate of the *P*-MOS is pulled up and the transistor that pulls it down has no base current before you press the switch.

@@0x8badf00d Uh. It can start in the on state. You're clearly missing something in your highly simplified response. Don't be a shit.

Jeremiah Lowe There is a core group of people who thumbs down all my videos, some within minutes of uploading. They haven't even watched it yet. I don't know about other channels, but I have a core group of haters!

EEVblog that's how you know you're doing something good :)

EEVblog i knew itd be something like that btw do you know any cheap power supplies like under 50$ mine broke and idk why it was a computer PSU anyways

Almost all videos have approx. 1% downvotes. That's the "standard". Less downvotes than that is either a video on a small channel or what you could call "exceptionally" good. A higher percentage means you either said something controversial or just too much stupid/boring stuff.

EEVblog You're pretty harsh sometimes and some people really don't like that. Me on the other hand I would give thumps up for the sole reason of being able to speak clearly even if it means to bash people who deserve it. Well that is if I could get myself to use the (dis)likes buttons at all. I believe they are made for immature people who actually beleive quality derives from how many likes one gets. Even though enormous amount of proof points in the opposite direction, stupid people (which includes most of the human kind) still cling to the lie. You are doing a great job teaching electronics and I hope it is enough money for you to keep on making videos until death. If it was something I would like to see more of it would be rf. Maybe even a simple DIY spectrum analyzer just to crack the nut about it being so hard. You are a great teacher and you would know how to make so called hard stuff simple to understand. Against, I really appreciate your videos.