Circuit Help

Discussion in 'The Projects Forum' started by £clipse, Oct 13, 2008.

  1. £clipse

    Thread Starter New Member

    Oct 13, 2008
    2
    0
    Hi, I'm building a LED dimming circuit and i have a question about the schematic,

    http://www.reuk.co.uk/OtherImages/ne555-pwm-led-dimmer-circuit.gif

    On the far left under R1 I don't understand what the IN4148 is. Well let me rephrase that, I know what it is a 50k pot connected with two diodes(Germanium in this case) but I do not understand what the IN4148 means. Could anyone care to explain? Any help would be nice.

    Thanks
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
  3. £clipse

    Thread Starter New Member

    Oct 13, 2008
    2
    0
    Thank you,

    I misread the page and it was talking about how ger. diodes can be put in place of the 1N4148 for more light out of the LED's. :(
    Anyways thank you very much for answering my question in a short period of time. Howver one last question, what do you think of this LED dimming circuit?

    Thanks
     
  4. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    You can replace the 1N4148 with schottky diodes since they have a lower forward voltage like the germanium diode but are much less sensitive to temperature.

    hgmjr
     
  5. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    I don't think the forward drop of the diodes will make any visible difference in the circuit operation. If if works from bright to dim, what's not to like? Low component count is always admirable.
     
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