3 Major switch types in circuits!

Imagine that you have an AC lamp or a DC motor and you want it to turn on and off automatically, not by pushing a button or something like that. In this case, what switch should you use to get the best results? You have many choices, triacs, transistors, relays and some other stuff. Which one is best for your load? Switches are integral members of any circuit or any electronic product, because of that it is critical to know about them and select them with scrupulosity. In a very basic classification, switches fall into two main categories, mechanical and electrical switches. The main topic in this video is about electrical switches but in the beginning we will take a brief look at mechanicals. Mechanical switches are physical switches, which must be activated physically, by moving, pressing, releasing, or touching and so on. For example, DIP switches, slide switches, push buttons, tactile switches, toggle switch, rocker switches, limit switches, joysticks, et cetera. On the other side there is electrical switches, which do not require any physical contact in order to control a circuit and they are activated by electrical signals and they let us automate processes, because they do not require human operator to start or stop things and processes. there is 3 main factors to choose a switch type for a load; current type, speed and signal type; also there is other factors like weight or price and so on which is not as important as our main factors. You must consider these 3 parameters in order to selecting the proper switch type: Parameter Number 1: Current type your load works with, (I mean AC or DC; for example this fan works with AC and this motor works with DC) Parameter Number 2: How fast you are going to switch (if you intent to just turn a light bulb ON and OFF then you does not need much fast switch, but maybe you have to dim a light bulb by switching the bulb ON and OFF very fast, in this case you need a fast switch) And Parameter Number 3: importance of signal details (sometimes you are going to switch signals like sound or video, in this case you have to choose a switch to keep signal shape and details) Now that we considered 3 main factors, it is time to select a proper switch. Let’s take a brief look at those electrical switches. First Switch Type: TRIAC Triacs are AC switches and they are very fast, silent and they can switch on or off many times or almost unlimited. There are many details about triacs and how to select proper part number of them (like package type, power dissipation, maximum current, and whatever) but those details is not related to subject of this video. Next week I will release a specific video about triacs to cover many details about them. I will cover best way to connect a triac to microcontroller, how to select best part number from numerous options for a particular load, precautions and so on. Second Switch Type: TRANSISTOR Transistors are DC switches and they are very fast, silent and they can switch on or off many times or almost unlimited. Also transistors have many parameters (like collector-emitter voltage, maximum collector current, HFE, whatever) and they are available in numerous packages and types out in market and it is very important to select best part number for a particular load. I will cover detail about transistors in one of my next videos. Third Switch Type: RELAY Last switch that I will talk about it is relay. Relays can switch either AC or DC and even media signals like Sound or video but they are very slow because they include a mechanical contact (they can switch ON or OFF utmost 10 times per second) and have limited times to switch on or off. They will lose their quality after a certain number of toggles. Relays make sounds and in same condition they are more expensive than triacs or transistors. You must think about how awful relays are by what I said; slow, noisy, expensive, and limited times of switching. I think there is a confusing question. What make relays valuable? With those disadvantages, why relays do not disappear from designs? In addition to ability of relays to switch either AC or DC currents, there is at least two other factors to make relays valuable. First one is isolation and second one is keeping signal details. I will explain these items in next videos. to summarize the content, I have to say if your load works with AC, you can use either relay or triac but best choice is to use triac and if your load works with DC, you can switch it using either relay or transistor but it is better to use a transistor and if your circuit needs to isolate control section with load and power sections or you have to keep signal details, like sound or video or something like that, you have to use relays.

[@KAAN876]

Thank you very much for your valuable video, and your explanation is so smooth and understandable

[@elewizard]

You are welcome! Keep watching bro👍

[@brianwood5220]

Very Helpful, thanks.

[@elewizard]

Glad it was helpful!

[@user-mr3mf8lo7y]

Much obliged. Would it be possible to see a video about frequency counters.

[@elewizard]

Yes of course, but not soon😉

[@michaeltina3866]

Nice video sir ❤❤

[@elewizard]

Thanks❤️😊

[@moeburn]

Hey in your other video you showed a small triac powering an incandescent bulb (a high current load). I thought triacs could only handle tiny loads like 100mA? I am going to be controlling an 85w (0.74A) load on 110v AC with a microcontroller (I am making a smart thermostat for line-level-voltage thermostat wiring) and I opted for a nice solid-state-relay package, but could I have used a simple triac?

[@elewizard]

Yes you can. Handling high power loads using triacs is not unusual. An ordinary triac can switch 1000w loads

[@chilledoutpaul]

i use electronic relays in some of my projects because of the current rating and are more reliable than mechanical ones

[@elewizard]

Yeah, SSRs are perfect for AC 👌

[@Embeded_Geek]

power loss in Triac is higher than Relays. triac can last forever but relay has limited switching cycles.

[@elewizard]

👍

[@Embeded_Geek]

maby use optocouplerfor isolation in triac

[@elewizard]

Maybe

[@Reneg973]

​@elewizard so your last sentence is not completely correct. With required isolation and AC a relay or an optocoupled triac can be used

[@rickytosiro2836]

Could you please help me with my project

[@ChandrashekarCN]

💖💖💖💖

[@elewizard]

❤️❤️❤️❤️❤️

[@ChandrashekarCN]

channel changed??

[@elewizard]

Yes, there was a problem with my old channel. This is my new channel, I am going to add old videos along with new videos here 👍

[@ChandrashekarCN]

@@elewizard how do i know it's you (original) or some one with your videos???? 😂

[@elewizard]

@@ChandrashekarCN good question. Simply wait for new videos 😉

[@ChandrashekarCN]

@@elewizard its a AI stone age i don't believe until i saw you in person and check 😅

[@elewizard]

@@ChandrashekarCN i think creating an Instagram account will be a good idea, I can inform you there. So for this case you can send me an email. I will reply you an send a video for you.