Hi,i am into a project where in some TRIACS(solid state relays) are to be controlled by an audio input! I got LM3915 first in mind to start with.But the outputs of it will be lows.I used inverter 74LS04 to get high and used it to turn on BC547 transistor which inturn turns on relay. But now the problem is the output of 74LS04 is now way enough to turn on BC547. Similarly used ULN2003,and got a doubt,whether it can be used where in input low is fed and output high can be got? I am desperately searching for some practical solution,tried ULN2803 also. Can anyone get me easy solution for the task? I need to solve this within 2 to 5 days.Your replies will help me to a very greater extent.