Help with simple signal manipulation IC

Discussion in 'The Projects Forum' started by diddy02, Aug 12, 2010.

  1. diddy02

    Thread Starter Member

    Sep 26, 2008
    Hey all,

    I'm trying to take a +/- 10V input [called MVP_IN in my schematic] and output two signals.

    1) OC1: +5V logic signal that is 5V when input is (+ve) and off otherwise.
    -- used an op-amp as a comparator

    2) VCO: An inverted magnitude of the input amplified to 15V.
    -- used dual op amp full wave rectifier to get correct magnitude, then a second stage op amp to invert, offset and amplify the signal

    An example of the desired output signals is shown attached. I simulated with a sinusoidal input.

    I've attached my schematic and was hoping for some tips/critiques. The biggest thing that bothers me is the 15V offset I need to provide the VCO signal. Is there a better way of doing this? I'd appreciate any advice on any part of the IC... this is my first time designing this sort of circuit.

  2. windoze killa

    AAC Fanatic!

    Feb 23, 2006
    If it works in the sim and you have the outputs you want then buy some vero board and get cracking. They are only cheap parts so buy a few just incase. Ensure you have plenty of decoupling caps around the power lines.