Amplifying a Sine Wave

Discussion in 'The Projects Forum' started by RanHam335, Jun 20, 2013.

  1. RanHam335

    Thread Starter Member

    Dec 4, 2008
    I want to start a project making an inductive guidance robot. I picked up a Velleman mk105 kit pretty cheap. It generates a 1 khz sine wave. I don't have an oscilloscope but my meter says its outputting a 168mv signal. I want to use this for the guide wire. I have 10mh inductors. I figured 168 mvolts wont hurt anything if I short it out. So I did with some wire to try to see if I could induce anything in the inductor and no luck. I think I need to amplify the signal so it can induce a voltage but I don't know how to do it. I know the more current I have going through the guide wire the bigger the magnetic field it'll create around the wire.

    Also Do you guys know any formulas for inductors to figure out how much induction there will be?

    schematic of sine wave generator:
  2. LDC3

    Active Member

    Apr 27, 2013
    There is a program that uses the microphone input as the input to an oscilloscope. It is limited to about 20 KHz since the input is designed for audio. The program is WinScope.

    Most DMMs have a poor response with a 1 KHz signal. I believe that the voltage level is greater than the 168 mV that your meter finds.
  3. Shagas

    Active Member

    May 13, 2013
    This kit can give an output up to 900mV by varying the pot if i'm not mistaken . I've got one aswell .
    But seeing as there is a pot on the output you'd want to feed it into a buffer if you want to connect an inductor because as soon as you connect it to a load your output will drop significantly .
    Google Op amp buffer circuit , it's just connecting 2 wires together with an op amp and try feeding that output to your inductor or whatever you are trying to make . Also put at least 300-500 ohm resistor in series with the inductor .
    The inductor itself is a very low resistor and when you connect an output as you did across it then you are basically shorting it and the voltage on the output drops down to almost to zero levels