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    Amplifier circuit for UV-led

    I have a function generator (Escort EFG 2210) as a source to a UV-LED (LED255J ). The FG delivers about 7.5 Vrms and 30 mA pulse signal. The LED requires closer to 100 mA for optimal emission. The voltage is good enough. I have tried various amplifier circuits, but end up with less current than before.

    Any ideas?

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    Re: Amplifier circuit for UV-led

    Hi,

    not much details.

    What signal waveform? Is it just digital or to you need analog control of LED.
    If analog: you should look for voltage to current amplifier cicuit.

    Klaus



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    Re: Amplifier circuit for UV-led

    A non-inverting opamp can drive a transistor as an emitter-follower and there can be negative feedback for a voltage gain of 1. You will need a series resistor to the LED for current limiting.



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    Re: Amplifier circuit for UV-led

    Audioguru solution is better because of its constant current nature. If you are looking for something more simpler follow circuits here:

    http://electronics.stackexchange.com...common-emitter



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    Re: Amplifier circuit for UV-led

    Quote Originally Posted by zoulzubazz View Post
    Audioguru solution is better because of its constant current nature.
    No, my circuit is constant voltage, not constant current. The input is listed as RMS so it might be a sinewave. The series resistor and input voltage establish the current.



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    Re: Amplifier circuit for UV-led

    Quote Originally Posted by Audioguru View Post
    No, my circuit is constant voltage, not constant current. The input is listed as RMS so it might be a sinewave. The series resistor and input voltage establish the current.
    A Slight re-arrangement makes it a voltage controlled low side current sink.




    simulation link




    R=10 controls 1V/ 0.1amp. regulation. For faster ON to OFF state transitions, this should be specified then added.
    A good design question lists your overall requirements™ The best question deserves a better answer. ™
    ... Tony Stewart EE since 1975



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