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Transistor Logic Gates

Transistor Logic Gates

This video shows a few logic gates I built with some NPN BJT transistors and why they work like they do. AND, OR, NAND, and NOR and the four gates I built in this video.


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Tags: transistors

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  1. Date: August 31, 2015 at 02:12
    Author: unlokia

    So simple, and so very clear and excellent. You are indeed a master of simplicity in explanation, and should be applauded for this superb video. God bless you! 🙂

  2. Date: November 3, 2015 at 13:18
    Author: MThe3

    Thank you bro. you make it look easy. Unlike my professor :/

  3. Date: November 23, 2015 at 13:21
    Author: Dipankar Gogoi


  4. Date: April 17, 2016 at 10:15
    Author: Aladinx36

    How can i make A=0,B=0 light nr.1 led ,A=0.B=1 nr.2 led, A=1,B=0; nr.3 led and A=1,B=1 nr.4 led ???????????????????
    Please help

  5. Date: September 4, 2016 at 21:20
    Author: Aakash Shah

    In the AND Gate, if the A & B are 0 & 1 respectively,

    Why is the result 0?

    Should't it be 1?
    If the currrent is flowing from the collector to the emitter in the B transistor.

  6. Date: November 5, 2016 at 23:08
    Author: Simon MacLean

    what I still dont understand is why the current wouldnt flow through to the output, even if it can go through the transistor (for NAND, and NOR). why doesnt it go through both?

  7. Date: November 5, 2016 at 23:12
    Author: Simon MacLean

    if my power supply comes from a 9v battery, what resistor values should I use?

  8. Date: November 7, 2016 at 16:39
    Author: Mike Miller

    Thanks! The best NAND gate explanation. The only thing i've missed: why did you put a resistor to the input line in that case? and what serves a "ground" if we talk about computers?

  9. Date: November 20, 2016 at 20:03
    Author: Fenn Saji

    How do I determine the value of resistors to be used?

  10. Date: March 22, 2017 at 22:29
    Author: Rabah Osman

    thank you very much. Now I see how circutes are working and I can draw one. So happy that I found your video.

  11. Date: March 31, 2017 at 19:31
    Author: Paul

    Best gate explanation of gates I have seen yet. Here is a challenge for you. Make Exor and Xnor gates with 2 transistors. You may need PNP transistor for this one 🙂

  12. Date: April 10, 2017 at 17:58

    For the or gate, can't you connect A, B and the output together unstead of using transistors ?

  13. Date: July 3, 2017 at 22:30
    Author: ncarrasco2006

    Hi, to do a circuit analysis and to calculate the resistances, voltages and current is correct to separate the cases when the switch is ON and when the switch is OFF ?

  14. Date: July 21, 2017 at 06:09

    Who the fuck disliked this video. They are the dumbest people I've ever seen. Fuck 'em.
    What a great explanation. You got a Subscriber…!

  15. Date: July 26, 2017 at 14:49
    Author: vidhya priya

    thank you sooo much brother ..
    clearly explained no doubt
    thank u brother
    may god bless u

  16. Date: August 1, 2017 at 10:59

    Good explanation. One correction on the AND gate, you said when A is on and B is off, current flows through A and stops at its emitter. Not true. No current flows through either transistor because there is no path to ground with B still being off. Always remember a circuit has to have a path to ground to be complete.

  17. Date: November 19, 2017 at 06:37

    Hello sir,, Read please, in And gate, when A is low and B is high why the output is 0 or low. While we connect A to ground and B to High voltage wouldn't the base-emitter junction of the second transistor forward biased? then why it is Zero instead of 1

  18. Date: December 16, 2017 at 08:05
    Author: Bar??

    so great that i've finally found someone who can teach this in a simple manner

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