led How can I effectively reduce the voltage needed to activate a transistor


Posted on Feb 7, 2014

A circuit which basically connects the line out (audio output) of a music playing device to a set of LEDs (actually a huge strip of around 200 LEDs), so they flash in time with the music (from internet tutorials - I`m a bit of beginner). My circuit works very well using my laptop as the audio device (connecting my circuit to the headphone jack on it). But when I use something smaller such as an iPod, the lights barely


led How can I effectively reduce the voltage needed to activate a transistor
Click here to download the full size of the above Circuit.

turn on at all. I`ve tried using a Darlington Pair (below), but that makes the issue worse. This is why I think the issue is that the audio line out is not reaching the 0. 7 volts across the base and emitter that the TIP31C transistor needs to activate (the Darlington Pair means it now needs 1. 4 volts to activate). From my research, it looks like using an op amp might be the way forward, to amplify the audio line out signal before the TIP31C transistor. Would somebody be able to suggest one, and which inputs I should connect to




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    PC Printer Port Controls I-V Curve Tracer
    Divide-By-N + 1/2 Circuit
    1Hz Timebase For Readout And Counter Applications
    atmega8 voltmeter
    FM wireless transmitters
    heater with ckm005 microcontroller
    circuit 10a variable power supply symmetric
    30w vhf fm broadcast amplifier
    20 kHz ASTABLE
    Loudness Control
    RF Probe and Watt Meter
    Sanyo 83P switching power supply circuit diagram



    Top