Working Principle of BJT Transistor with Water Level Circuit Example

[@chrishuhn5065]

Just a nitpick and a tip for the total newbies: Yes, the longer leg of a LED is the anode that is connected to DC plus (or VCC). But if the LED legs are equal length you can't identify the anode this way. When you take a closer look at the LED, you see that the metal plates inside have different sizes. In 99.9% of the time the smaller plate is the anode. In the image shown here it's the other way around, which is wrong. So if you try to build this and it doesn't work, swap the connections to the LEDs around.

[@chandraguptarajah6090]

It is very interesting to get taught from you

[@eeapplications]

I didn't understand how that is 😅

[@sridharkrishnappanavanerth3388]

Nicely explained. Sir, can we alter the circuit such a that when water level is full only the corresponding led (4th) must light up rest others are off similarly when water level is at 75 percent full the 3rd led should light up all leds bellow should be off. At any water level only one led must be on. Is it possible sir, if so can you make a video to demonstrate and explain the circuit with diagram.

[@apnaagritech786]

Wow, good and useful circuit and its detail and working principal. Thanks for sharing. Gift.🌻🌹🌹🌹🌹💯✌💐💐🌼💝🎁🎁🎁🎁👍👍👍👍👍👍👍👍🌻

[@eeapplications]

Thank you so much ☺️

[@RC-Heli835]

Awesome stuff man! What is the tune playing at the end?

[@eeapplications]

Thank you so much 😊 This music is "Jazz in Paris". You can find in KZbin sound library.

[@RC-Heli835]

@@eeapplications Ok thanks love it!

[@johncole3602]

Quick question: Shouldn't the resistors be placed before the Led's to avoid be burnt out? 🤔

[@eeapplications]

Since resistors and LEDs are connected in series, their location does not matter. Because the same current flows through both of them.