Motion Detector without PIR module! Analog circuit Explained

[@wizhippo]

Love the practical example along with the realistic problem solving of external variables. These videos showing real applications and implementations are my favourite. Not sure if it was planned but glad it happened.

[@elewizard]

Great to hear! They are planned 👌

[@petersdelucaaa2vg306]

You are so good at explaining how electronics work. Thank you. I am looking forward to more of your educational videos.

[@elewizard]

Awesome, thank you! More videos are coming

[@mikejones-vd3fg]

As someone trying to learn electronics strictly through youtube videos (probably not the most efficient way) this video is very enlightening and much appreciated. Seeing a circuit evolve and troubleshooted makes resistor choices more clear and logical. Usually we just get told "use X resistor here ,its common practise". Im surprised it worked so well i think I will try this technique for a mouse trap ive been putting off, mainly because the PIR modules i intend to use arent that straight forward to use, and ive been having good luck with just using them to catch the mouses manually - by extending the light the PIR is attached too into my room that turns on notifying me the mouse is in the box i set out, which i come by and close the entrance while the mouse just sits there thinking i dont know its there. Winner winner, mouse dinner. JK i release them, but theres 1 left and it wont sit there ... I need a switch to close the entrance but need detection first. Thought about usin that vibration detectoin IC that comes with the arduino kit and then the PIR module but the ciruity looks way more complicated and i think going simple is smarter to start, then work up to something more complex if its even needed. Anyway great video and nice results ,the increases and decreaseing could even be used to tell you if something is coming or going, more infromation then a PIR module can even give, very nice.

[@elewizard]

Thank you for watching and thank you for sharing your experience with me ❤️

[@johannesvanschalkwyk304]

I don't think the idea was to design the perfect circuit, but to explain and show the concepts to people like me who has no electronics background and who simply likes to play for the fun of it. Thank you for this lesson, I always wanted to understand op-amps better. I know there is a way of using a NE555 to create a switch that stays on when triggered untill it is triggered again. I was thinking if I combine that with this, I will have a neat portable intruder alarm. Something more to play with :)

[@elewizard]

Great point!

[@kennymanchester]

Several lessons in one! Great working through iterative process of solving problems to get what you want. Noise mitigation is near and dear to my heart! I was wondering if you were going to pull some l-c filtering too! ;) I love the overhead shot w the scope too. Unique to me and I love it, well done and effective. Also becoming one of my fav channels too. Many thanks for your time and sharing your obvious skill with us.

[@elewizard]

Thank you so much for your warm an kind comment. Keep watching ❤️

[@peterlethbridge7859]

This is a brilliant video, really informative. Thank you so much for your time and effort. Once again, it's another great video from you. Can't recommend this channel high enough. Please keep going. Your work is greatly appreciated.

[@elewizard]

Glad you enjoyed it! Thank you for your support ❤️

[@jlawrence71]

WOW, great job. Your method of explanation is VERY good. I really understood everything. Thanks !!

[@elewizard]

Your comment put a big smile on my face. Thank you for being a part of the community ❤️

[@t33th4n]

You sir, are an excellent teacher!

[@elewizard]

Thanks! 😃

[@arp_catchall]

Your videos are so original. Thanks!

[@elewizard]

Glad you like them!

[@mmg.mousavi5613]

مثل همیشه عالی👍👍موفق باشید

[@elewizard]

Thank you for watching ❤️

[@petersdelucaaa2vg306]

Amazing! I finally had the time to put the motion detector together on my breadboard. This hands on method is the best way to teach as I learned so much from this project. I do have one question. What is the purpose of the diode that is connected between the positive and negative terminal of the buzzer? I also can't stop playing with it. Thank you.

[@elewizard]

It is really funny to play with that circuit 😃. The diode is called flywheel diode. It is used in parallel with inductive loads. The buzzer is inductive load. If you ignore it maybe you didn't feel amy different, but in noisy environments it will shot its impact.

[@smokingsolder39]

Love it. Well explained throughout presentation. This is beginning to be one of my favorite channels.

[@elewizard]

Wow, thanks! 🥳

[@electronic4hame]

Hi Professor, thanks for your good training. ❤❤

[@elewizard]

Thank you so much for your support my dear friend ❤️

[@koenvandemoortel2206]

Very nicely explained!

[@elewizard]

Glad it was helpful!

[@RaviKodali-et6st]

Amazing explanation sir

[@elewizard]

Thanks for watching

[@GeRoNiMo-m4v]

Impressive and full of knowledge...Thank you!

[@elewizard]

My pleasure!

[@RexxSchneider]

When you have a noisy input signal, hysteresis is your friend. A little bit of positive feedback (a large resistor from output to non-inverting input) will ensure clean switching from one state to the other without transmitting any of the noise to the output. I'd recommend using comparators rather than opamps in open loop for these sort of applications as they are happy with bigger differential inputs and are much less likely to lock-up under unexpected conditions.

[@kennmossman8701]

well while that is true it is mainly used if the signal is erratic. Noise is handled via filters

[@kennmossman8701]

for newbies a omparator uses a different circuit - it is not a direct replacement

[@kennmossman8701]

comparators will also switch faster

[@elewizard]

Thank you for your recommendation 👌

[@RexxSchneider]

​@@kennmossman8701 1. If you want to use filters, then you are adding an additional stage of complexity. It's not necessary when the noise is small. The Schmitt trigger is used to combat small amounts of jitter anytime we want to switch cleanly, and you only need one resistor to implement the positive feedback in this circuit. 2. Nonsense. The comparator is used in the same circuit as an open loop opamp. That's because a comparator is an opamp that has been designed to accept larger differential voltages and (usually) a larger common mode range. 3. Common comparators like the LM393 have very similar internal circuitry to a common opamp like the LM358, apart from an open collector output rather than the push-pull on most opamps. That leads to similar performance and switching speed. You can get faster comparators and faster opamps, of course, but for these sort of circuits switching speed doesn't really matter.

[@mrashad219]

Thanks! Can you show the internal workings of Inductive/capacitive Proximity Sensors like lJ12A3/used in industrial control applications. I took one apart, after wrestling and boiling the epoxy resin, found a board with bunch of SMD components, some of the component came loose and the main npn transistor was scratched beyond recognition. I would love to build one on the breadboard and use when I'm lab tutoring.

[@elewizard]

Thank you for donating ❤️ Yes certainly, but I am not sure when.

[@andymouse]

Awesome!!...cheers.

[@elewizard]

Thank you! Cheers!

Thanks.

[@elewizard]

You're welcome

[@MlokKarel]

Great video! Mükəmməl, həmişəki kimi! Artıq başqa videonu səbirsizliklə gözləyirəm! 😁 Hope I didn't butcher your mother tongue too much 🥲

[@elewizard]

It is completely correct, Google translate works well 😉. Thank you for your support 🥳

[@carldavis8228]

Thanks!

[@elewizard]

Thank you so much for your donation ❤️

[@supremeleader5516]

Did you changed name of your channel or this is new channel?

[@elewizard]

This is new channel, the old channel is available as well.

[@marklibich415]

Why wouldn't you just use a Wheatstone Bridge for the triggering part of the circuit? I think it would be much more sensitive.

[@elewizard]

Yes, it would be more sensitive, but here in this video I prefere to focus on concept, not circuit itself 👌

[@7gurshaansingh6thmarigold58]

Sir, In self oscillating flyback converter crkt. How pules generates without ic ?

[@elewizard]

Good question, maybe it can be a greatsubject for a video 👌

[@illusionarylife5741]

If ldr reduces resistance in light, then would not connecting point a to +ve keep output high when illumination increase?

[@elewizard]

No, the LDR is not connecting something, it is making a voltage 👍

[@illusionarylife5741]

@elewizard Sorry for not makimg my question clear. If light increases then voltage would increase at point a, right? If point A in circuit is connected to +ve pin of comparator, then the output of comparator should be high? Although in the video you say the opposite in the last circuit where both comparators are connected. That's what confuses me. Thanks for the reply.

[@DevisinghRathore1308]

😂Yes.... We found the criminal was epic 😅

[@elewizard]

🤪

[@ChandrashekarCN]

💖💖💖💖

[@elewizard]

❤️❤️❤️❤️❤️

[@3D_Printing]

Mmm turn the main room light on and off

[@kennmossman8701]

Strictly speaking a PIR is not a motion detector - it detects changes in heat. A photo-cell would be less useful,,,,,,,walkimg into a dark room [unless you were carrying a light source] would do nothing' you need to either shine/reflect light onto it or block an existing light source

[@elewizard]

Yes you are right, but you can replace the LDR with a photo diode, then this circuit will be able to detect infrared changes in environment. Or you can replace the LDR with a microphone, then the circuit will be able to detect sound in environment. In this video the concept is more important than the application

[@user-mr3mf8lo7y]

Glad you found the culprit. Is 1N4148 really necessary on buzzer leads?

[@kennmossman8701]

A power diode such as the 1N400 family is effective at lower frequencies [and can handle more current A diode will prevent back EMF

[@elewizard]

No, it not necessary, it is recommended

[@086390319003]

Very super and deep explanation

[@elewizard]

Glad you liked it😊