Oscillator Check

Thread Starter

crazyengineer

Joined Dec 29, 2010
156
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?
 

praondevou

Joined Jul 9, 2011
2,942
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.
 

BillB3857

Joined Feb 28, 2009
2,570
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.
 

Wendy

Joined Mar 24, 2008
23,421
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.
 

RRITESH KAKKAR

Joined Jun 29, 2010
2,829
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
 

Audioguru

Joined Dec 20, 2007
11,248
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.
 

#12

Joined Nov 30, 2010
18,224
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.
 

PeeSeeBee

Joined Jun 17, 2011
56
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?
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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