Awesome, I must watch the SCR video now. You are very knowledgeable, I can tell by the way you teach. You have a solid understanding of the fundamentals. A joy to watch, keep up the good work.

great explanation!!

So if I understand well your example with diode connected to the gate, when diode is connected in one direction, than first of the two SCRs conduct and when diode is reverted than second one of SCRs conduct. That is the reson why we have these half cycles on the osciloscope. That has total sense of course. What does not make sense is the story with quadrants, it is not in coleration with this mentioned above. To be colerated gate voltage need to be + for 1st and 2nd quadrant and - for 3rd and 4th quadrant.

Tanks a lot, easy to understand! Would a triac could be used as a audio signal switch if you put a constant voltage to the gate via an external turn switch?

I like your battery charger but My battery doesn't have a power pilot pin So is there any way around that pilot pen so I can use this as my charger I'm charging at 36v battery that over 190amp hours made 10 ten in Series and a 100 in parallel in 10 lines of 18650 cell like the idea Having some control over voltage and charging amps if u can helpI would appreciate it or if anyone's watching his videos can help out thank you

Hey man i don't know if you'll receive this but i was wondering whether it was able to turn on and off a PC fan that is soldered to a power supply? i would like to make an air conditioner integrated into my Simulator cockpit but to do that i need to wire my fan to a power supply like you showed but also a on/off button. Maybe also a dial which allows me to controller the speeds maybe? i also sent this over Google hangouts as i couldn't find a email to contact :S Sorry about that...

i think that when you talk about quadrants the first two have positive gate voltage and the third and fourth have negative gate voltage...from minute 13...i can't understand why the 1st and fourth quadrant are positive and the other two negative gate voltage

make a video with the opto and triac

Thanks for this great video. So a traic is just two thyristors with a common gate - npNp and pnPn, where the gate is uppercase. www.electronics-tutorials.ws/power/power19.gif But, can gate be connected to two p (or n) layers? Like npNp & pNpn (or nPnp & pnPn) Would that allow us to control a triac with DC instead of AC? Are such triacs produced or that idea is completely broken?

4:33. This, to me, is the elephant in the room, and everyone keeps glossing over it. The SCR on the right will conduct when it's forward biased, as long as there's a negative voltage on the gate? Negative with repect to what? If it's truly two SCR's, shouldn't the gate need to be positive with respect to A2 to get the right SCR to conduct? I've seen a lot of circuits that turn the TRIAC by connecting the gate to A2 through a resistor. What gives, it should only turn on for 1/2 wave with that configuration. What am I missing?