function generator from pc audio port - Page 1
Forum section: electronics / general

author: OwaisAhmed
author_rank: Contributor
timestamp: January 30, 2022, 09:04:12 am
content: i don't have function generator or oscilloscope but i was looking for some sort of thing that can provide regulated high freqency sinewave or square wave so i thought about this idea. i just wonder if there going to be any problem using this method as a signal.

author: jonovid
author_rank: Super Contributor
timestamp: January 30, 2022, 10:34:25 am
content: IMO any pc audio port is only good for 40Hz up to 15kz and sine wave at best. basic audio worktry to get better if you cango to 4:19 on the videoHow To Set Up An Electronics Laborordering from china if you can?many kit type function generators on alie-xpreally need to know the type of work this is for ie hi fi or low fiothers may have better suggestions

author: tunk
author_rank: Super Contributor
timestamp: January 30, 2022, 01:17:47 pm
content: What do you mean by high frequency?Is this any help:https://youtu.be/Y1KE8eAC9Bk

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 30, 2022, 02:16:38 pm
content: Take a look at fl2k for a $5 3 channel AWG that can go up to 70MHz or so.

author: tooki
author_rank: Super Contributor
timestamp: January 30, 2022, 03:15:59 pm
content: Quote from: jonovid on January 30, 2022, 10:34:25 amWhere do you get those numbers from? A standard 44.1kHz/16-bit audio output supports 20Hz-20KHz. Nor are non-sinusoidal waves a problem at lower frequencies. If the goal is audio work, then it's fully sufficient to match human hearing. (Since the bandwidth limits of the audio output are better than those of human hearing.)

author: tooki
author_rank: Super Contributor
timestamp: January 30, 2022, 03:19:16 pm
content: Quote from: OwaisAhmed on January 30, 2022, 09:04:12 amI've done this, but it's only for audio frequencies. "High" frequency in electronics often means frequenciesfarabove audio frequencies, so using a PC as a signal gen is mostly useful for audio projects and very basic, low-frequency stuff. But it's really no substitute for a real signal generator, since it can only generate AC signals with no DC offsets, which limits its uses.

author: jonovid
author_rank: Super Contributor
timestamp: January 30, 2022, 07:23:20 pm
content: Quote from: tooki on January 30, 2022, 03:15:59 pmI did the same with an XP windows software tone generator application , in the instructions it did say 15kHz upper limitbut this maybe a software coding limitation.may also be to my age related hearingothers on youtube have saidstandardpc audio is not the full flat 20Hz-20KHz

author: SmallCog
author_rank: Frequent Contributor
timestamp: January 31, 2022, 02:33:02 am
content: If you've got nothing else splashing a few dollars on one of these isn't the worst idea everhttps://www.ebay.com.au/itm/403325035966?hash=item5de80ba5be:g:GZ0AAOSwvCJg~20f&frcectupt=true

author: Bassman59
author_rank: Super Contributor
timestamp: January 31, 2022, 03:47:39 am
content: Quote from: jonovid on January 30, 2022, 07:23:20 pmIf a PC audio output doesn't pass 20 Hz to 20 kHz flat to maybe 1 dB, then it's broken. They're all capable of doing it. Perhaps the "others on YouTube" don't know what they're talking about? It would not be the first time.

author: OwaisAhmed
author_rank: Contributor
timestamp: January 31, 2022, 02:32:13 pm
content: thanks to everybody for helping me out. i'm gonna buy 10 dollar function generator kit because the voltages on pc audio port is also low. btw my application was putting and square wave signal on base of a transistor like in amplifier but not to run speaker on it. and sometime checking circuit working on square wave vs dc. for example capacitor timing and ripple. the only reason i was looking for higher frequency was to make small size higher frequency transformer and understand affect of frequency on electromagnetism induction. again thankyou to everybody.