Hi.
I am currently using a soundcard as a scope :
Hardware setup :
http://www.ladyada.net/library/equipt/diyaudioprobe.html
Software :
http://www.zeitnitz.de/Christian/scope_en
I will get a real scope but in the meantime i have a question.
I am trying to use my 'scope' to read the RPM of a magnetic-stator/rotor setup.
I am putting the 'probe' on a hookup wire that gets pulsed with a charge every time the reed-switch closes.
I was hoping that the frequency read-out from the scope (divided by the number of poles) would give me the RPM but it seems to fluctuate a fair bit and i know the RPM is not fluctuating that much.
Is this due to noisy PC electronics, does anyone have any experience with this poor-man's scope ?
Thanks.
now i've blown the mic input on two soundcards, onward and upward ;+}
i am workinking since years with tis.
you must not overload the input.
eventually limitimg with serie resistor or voltage divuder
gp
Quote from: pese on April 05, 2010, 06:56:43 PM
i am workinking since years with tis.
you must not overload the input.
eventually limitimg with serie resistor or voltage divuder
gp
Thanks pese. I am using a potentiometer and a 47mF cap but still blew the mic input, not sure why as i am new to electronics.
Quote from: DeepCut on April 05, 2010, 07:27:06 PM
Thanks pese. I am using a potentiometer and a 47mF cap but still blew the mic input, not sure why as i am new to electronics.
try to use an serie resistor 1meg (100k) between pot (slider) and input to card.
be sure thas briund is also connected tocard (otherwise it is try to have problems)
Use shilded (like coax) cables from pot to the card-input
pese
my suggestion :
use an external USB 2.0 to 3D AUDIO SOUND CARD ADAPTER, you can put all in a small box
http://cgi.ebay.co.uk/USB-2-0-3D-AUDIO-SOUND-CARD-ADAPTER-Music-Fairy-/280390165961
use this program is free:
http://www.sillanumsoft.org/
nice alternative:
http://www.elechouse.com/elechouse/index.php?main_page=product_info&products_id=396
Don't forget that you are limited by the frequency response of the sound card.
There are devices which plug into your USB socket, made, amongst others, by
Hantek, e.g. Model DSO 2150, which are more expensive but give better results:
http://www.hantek.com.cn/english/produce_list.asp?unid=63
"try to use an serie resistor 1meg (100k) between pot (slider) and input to card.
be sure thas briund is also connected tocard (otherwise it is try to have problems)
Use shilded (like coax) cables from pot to the card-input
pese "
Thanks pese, i will do that. Do you mean ground, when you say 'briund' ?
"my suggestion :
use an external USB 2.0 to 3D AUDIO SOUND CARD ADAPTER, you can put all in a small box
http://cgi.ebay.co.uk/USB-2-0-3D-AUDIO-SOUND-CARD-ADAPTER-Music-Fairy-/280390165961
use this program is free:
http://www.sillanumsoft.org/
nice alternative:
http://www.elechouse.com/elechouse/index.php?main_page=product_info&products_id=396"
Nice one Wings will check those out.
"Don't forget that you are limited by the frequency response of the sound card.
There are devices which plug into your USB socket, made, amongst others, by
Hantek, e.g. Model DSO 2150, which are more expensive but give better results:
http://www.hantek.com.cn/english/produce_list.asp?unid=63"
Yes thanks Paul i am aiming for the 2150 but can't get until next month :(
Paul
do you know how much?
Thanks
Chet
Quote from: ramset on April 06, 2010, 07:16:46 AM
Paul
do you know how much?
Thanks
Chet
Chet, 2150 on ebay :
http://cgi.ebay.co.uk/New-PC-USB-DSO-2150-USB-PC-Based-Digital-Oscilloscope_W0QQitemZ280480457484QQcmdZViewItemQQptZUK_BOI_Electrical_Test_Measurement_Equipment_ET?hash=item414df0230c
£140.00, free postage/packing.
Thanks D C
Chet
Quote from: ramset on April 06, 2010, 07:16:46 AM
Paul
do you know how much?
Thanks
Chet
On Ebay, they go new for around £100. But this model may not be
the latest or best.
Go to you own National Ebay, then to oscilloscopes, then put in "Hantek".
You can download from the net a number of these sound card oscilloscopes for free. Unfortunately, because of the capacitor at the input of the sound card these oscilloscopes cannot measure DC.
Quote from: Omnibus on April 07, 2010, 06:46:17 AM
You can download from the net a number of these sound card oscilloscopes for free. Unfortunately, because of the capacitor at the input of the sound card these oscilloscopes cannot measure DC.
Thanks Omnibus i didn't know that.
I have a thread on how to convert a USB mouse into a Dynamo-meter. The Dynamo-meter can simultaneously measuring torque and rotational speed (rpm). Here's a short video, http://www.youtube.com/watch?v=kSnnX1FwiWQ
The free software continuously plots RPM, Torque, and Power. It can export torque and power Vs. RPM curves to excel in .csv format.
For detail instructions and the free software, http://www.overunity.com/index.php?topic=8763.msg236980#msg236980
GB
Block what a great find :)
Very useful for those of us on a budget, i was wondering what RPM i was having, nice one mate !
Gary.