Oscillator Check

Discussion in 'General Electronics Chat' started by crazyengineer, Jul 23, 2011.

  1. crazyengineer

    Thread Starter Member

    Dec 29, 2010
    156
    2
    Hello. I'm getting ready to build a phase shift oscillator using the usual RC phase network and a transistor amplifier. However, I have no idea how I can check if the circuit is producing the correct sine wave since I do not have an oscilloscope. Is there a way to check to see if a circuit is producing a sinusoidal wave without this equipment?
     
  2. praondevou

    AAC Fanatic!

    Jul 9, 2011
    2,936
    488
    You could measure an AC voltage with a multimeter. But that gives you only a rough idea, since usually you won't know the frequency response of the multimeter. (if not a sine wave, it's even more difficult)

    Anybody who seriously wants to work/experiment with electronics, needs AT LEAST an oscilloscope, otherwise it's always more like guessing than measuring.
    If you experiment exclusively with low frequency, there are plenty of possibilities with A/D cards for PC (maybe even DIY projects) or even analog used oscilloscopes you should be able to buy an ebay.
     
  3. Jaguarjoe

    Active Member

    Apr 7, 2010
    770
    90
    Can you use a headphone or a loudspeaker?
     
  4. crazyengineer

    Thread Starter Member

    Dec 29, 2010
    156
    2
    Darn, no way to avoid getting an oscilloscope :(

    Oh well. Thanks everyone!
     
  5. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    There are several sound card scopes available that will turn your PC into a basic scope for the audio range. Do a Google search. Just have to be very careful not to send too much amplitude into your line input connection.
     
  6. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    He is right, they are basically free test equipment, dual channel scopes. The catch is 1. DON'T overdrive the input (this can be protected easily), 2. there is no DC measurement at all.

    The plus side is you can do phase comparisons.
     
  7. RRITESH KAKKAR

    Senior Member

    Jun 29, 2010
    2,831
    89
    Same with me without Oscilloscope it is very hard to Design, but you can atleast try without it many people make circuit .
    Now there are several USB Oscilloscope available, like from Parallax.com
     
  8. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    I think my projects started like this:
    1) Kit vacuum tubes stereo amplifier.
    2) Home-made big hi-fi 2-way speakers.
    3) Kit vacuum tubes oscilloscope (it still works perfectly 45 years later).
    3) Home-made sine-wave generator.
    4) Kit vacuum tubes FM receiver then a kit vacuum tubes stereo multiplex adapter for it.
     
  9. #12

    Expert

    Nov 30, 2010
    16,346
    6,835
    It's true. The first thing you buy is a multi-meter, the second thing is a soldering kit, the third is a 'scope, the fourth is a frequency generator. Only after that do you get some discretion about what to buy next. Sorry.
     
  10. PeeSeeBee

    Member

    Jun 17, 2011
    43
    7
    If you just want to check that it is oscillating (and it was designed for the audio range), connect it up to the "Aux" input of an amplifier via a capacitor.
     
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