Constant Current Source

Поділитися
Вставка
  • Опубліковано 24 сер 2024
  • In this video, I describe a constant current source used to drive the LED backlights of a LCD.

КОМЕНТАРІ • 37

  • @benthere8051
    @benthere8051 Рік тому +1

    Thanks, Craig. That's a very useful circuit. The two silicon diode voltage source is much better than a zener diode because the low voltage zeners are hard to source and only available in a limited number of voltages.

  • @ovalwingnut
    @ovalwingnut 5 років тому +1

    That was down right magical, as I try to wrap my head around "constant current". Thank you 👍😁

    • @craighollinger9972
      @craighollinger9972  5 років тому

      The circuit is "constant" within limitations, as I showed in the video, but is useful otherwise.
      Keep studying basic electronics, you'll get it in time. Thanks for watching.

  • @ThanassisTsiodras
    @ThanassisTsiodras 6 років тому +2

    Thank you, Craig! Useful circuit to know about, and very nice and clear explanation of its inner workings.

  • @cateyenebula
    @cateyenebula 2 роки тому

    Just what I needed to drive my DC optocoupler with an AC input. I just need to add an additional diode and I'm set. Thank you for the excellent explanation and demonstration!

  • @shvideo1
    @shvideo1 3 роки тому +1

    What a great circuit and so well explained. Thank you also for the component part numbers in your circuit. Great work.

  • @mokus8643
    @mokus8643 8 років тому +7

    nice clear job thanks...good teacher skills...cheers to you

  • @M0NTVHomebrewing
    @M0NTVHomebrewing Рік тому

    Thanks! Great explanation. Very helpful.

  • @wasiuadeleke6869
    @wasiuadeleke6869 Рік тому

    Thank you for your explanations

  • @Yorumcu63
    @Yorumcu63 3 місяці тому

    Great video

  • @zainaabdin
    @zainaabdin 4 роки тому

    Thanks....Simple. explanatory. useful. practical

  • @dd0356
    @dd0356 5 років тому

    thank you very much. very clear video. greetings from india!

  • @mark8664
    @mark8664 4 роки тому +1

    I prefer using an NPN transistor. Those PNP's give me a headache :)

  • @user-vp9wi1nk5k
    @user-vp9wi1nk5k 2 роки тому

    Legend brother

  • @carbonosilicio5318
    @carbonosilicio5318 2 роки тому

    Good explanation, you have very nice and soft voice always constant and clear but, if i may sugest, use some sort of a soft matt on the table in order to avoid those clicks and pops of the hard objects while moving them. It would help alot for some of us with sensitive hearing. Thank you.

  • @ziadfawzi
    @ziadfawzi 4 роки тому

    Thank you so much.

  • @konstantinosvafeiadis4548
    @konstantinosvafeiadis4548 3 роки тому

    Is it a good idea to put a trimmer (rheostat) of ~47ohm in series with the 68ohm resistor, in order to have a variable brightness on the backlight?
    Thank you very much for sharing your knowledge.

    • @craighollinger9972
      @craighollinger9972  3 роки тому

      That would work if you could find something that low in value.

  • @christianurgese
    @christianurgese 7 місяців тому

    What does happen decreasing source voltage ?

    • @craighollinger9972
      @craighollinger9972  6 місяців тому +1

      The circuit is quite simple, so not perfect. The current will change slightly as the source voltage changes (up or down), but it's pretty constant. That's the whole point of the circuit, constant current.

  • @horacewonghy
    @horacewonghy 2 роки тому

    voltage regular + series resistor = constant current

  • @MrBobWareham
    @MrBobWareham 7 років тому +2

    could you use an NPN instead of PNP

    • @craighollinger9972
      @craighollinger9972  7 років тому +6

      Yes, you can. Basically just turn the circuit over but keep the diodes pointing toward ground. The device you want the constant current to flow through now gets connected between the positive rail and the collector of the NPN transistor.

    • @MrBobWareham
      @MrBobWareham 7 років тому +1

      Thanks for that

    • @cancaonegro
      @cancaonegro 5 років тому

      Same question as you! :D

  • @deepakroy82
    @deepakroy82 7 років тому

    i need ur help

  • @hamaraapnaboutique5888
    @hamaraapnaboutique5888 7 років тому

    hindi m do

  • @labanchege5261
    @labanchege5261 5 років тому

    Was the first four minutes really necessary it makes tge video boring

    • @craighollinger9972
      @craighollinger9972  5 років тому +3

      When I find something boring in a video, I just use the slider and move ahead.