cheap usb oscilloscope for measuring amplifiers - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Class D

Class D Switching Power Amplifiers and Power D/A conversion

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 2nd September 2007, 06:02 AM   #11
fumac is offline fumac  China
diyAudio Member
 
Join Date: Oct 2006
Send a message via MSN to fumac
a traditional scope is better than the usb
even a analog scope.
a 2nd hand scope is not very expensive ,
perhaps a 300mhz bandwith scope is ok for class-d

will post a picture for u
  Reply With Quote
Old 2nd September 2007, 09:35 AM   #12
diyAudio Member
 
umut1001's Avatar
 
Join Date: Mar 2007
Location: Istanbul
Default hobby usb

Mhz amp is very good idea..second hand can be cheap in china but not cheap in Turkey..i think about hobby usb. http://www.hobbylab.us/USBOscilloscope/Home.htm

is there anyone using this?what do you think about it..also shipping is free to everywhere..
  Reply With Quote
Old 2nd September 2007, 09:46 AM   #13
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Have a look at the oscilloscope display.
That example of a 1050Hz signal is so full of sampling artefacts that one cannot assess the signal quality.

I don't think the 200ks/s sampling rate and the 10bit ADC are good enough for audio signals if this is typical of the output.

Waste your money on something else.
__________________
regards Andrew T.
  Reply With Quote
Old 2nd September 2007, 10:20 AM   #14
fumac is offline fumac  China
diyAudio Member
 
Join Date: Oct 2006
Send a message via MSN to fumac
Default Re: hobby usb

Quote:
Originally posted by umut1001
Mhz amp is very good idea..second hand can be cheap in china but not cheap in Turkey..i think about hobby usb. http://www.hobbylab.us/USBOscilloscope/Home.htm

is there anyone using this?what do you think about it..also shipping is free to everywhere..

no
forget about it
is not ok for anything
perhaps just for a newB to have fun

take a look at this pic, must at lease 100M scope. better is 300M
Attached Images
File Type: jpg 3.5mhz sq-mini.jpg (77.1 KB, 618 views)
  Reply With Quote
Old 3rd September 2007, 06:49 AM   #15
diyAudio Member
 
umut1001's Avatar
 
Join Date: Mar 2007
Location: Istanbul
Default hi about mhz amp

i really want to have a MHz amp..which mosfet can be used for this?it must be very fast and have lowest Qg and input capacitance parameters.do you have schematics?.if u have please e mail [email] umut1001@yahoo.com ..i think i will buy an owon lcd oscilloscpoe..but i must make money first
good luck
  Reply With Quote
Old 3rd September 2007, 10:45 AM   #16
fumac is offline fumac  China
diyAudio Member
 
Join Date: Oct 2006
Send a message via MSN to fumac
Default Re: hi about mhz amp

Quote:
Originally posted by umut1001
i really want to have a MHz amp..which mosfet can be used for this?it must be very fast and have lowest Qg and input capacitance parameters.do you have schematics?.if u have please e mail [email] umut1001@yahoo.com ..i think i will buy an owon lcd oscilloscpoe..but i must make money first
good luck

u can buy it from my Spain Agent ,
no schematics, sorry for that.

fumac
  Reply With Quote
Old 3rd September 2007, 02:30 PM   #17
diyAudio Member
 
Join Date: Dec 2003
Location: Munich
...I would say 100Ms is the 'should value'... better more..

I am using this one http://www.conrad.de/Elektronik-Mess...orsatz_dso.sap (forget the pic, it is showing the slower version DSO220).
THE DSO2100 is specified as 100Ms, but 100Ms is only available with alternating trigger and in this mode this scope is making some ten ns error between both chanels.... so for 100Ms you can only use one chanel.
Up to 50Ms it is working pretty fine. Bandwidth of the input stages is 30MHz. In fact this is really the minimum speed, which you need for class D.
Have a look to the screen shots in my threads. They are done with the DSO2100. Up to now this seems to be good value for the money. It has 2x11k memory, even if the spec says 32k. 32k are for both chanels together plus settings. You can use the data output also for Excel, but not with the integrated Excelfunction (instable), better open Excel and import the scope file.

(If you spend 800 EUR you can get 200Ms and 512k memory.)
  Reply With Quote
Old 3rd September 2007, 02:33 PM   #18
diyAudio Member
 
Join Date: Dec 2003
Location: Munich
...if you really want to design a MHz-amp then you should invest in a 200Ms scope minimum. And in Aspirin to cure your headache..
  Reply With Quote
Old 3rd September 2007, 05:13 PM   #19
diyAudio Member
 
umut1001's Avatar
 
Join Date: Mar 2007
Location: Istanbul
Default mosfet

yes i want to do it but i am an engineer and i dont want to buy mhz amp.i want to do it myself.i dont know which mosfet to be used in this amp.and about dead time qg an rds?.are the mosfets irf or st ?which model?

chocolic i will ask to aspirin but i think you know something about them..please tell me
  Reply With Quote
Old 4th September 2007, 10:35 AM   #20
diyAudio Member
 
Join Date: Dec 2003
Location: Munich
Active pharmatceutical ingredient: Acetylsalicylic acid.
In US supermarkets you can get them for a very competitive price in 200pcs packs.
Unfortunately I cannot make big benefit from that, because my average consumption is about one 500mg-pill per 3 years.
My biosystem seems to show more positive effects on chocolate & Diet Coke ...drugs...
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Measuring Hi-Fi Amplifiers korneluk Tubes / Valves 5 15th July 2009 03:16 AM
oscilloscope at victoria st. vinnie's. twelve bux, cheap! maxro Swap Meet 6 15th March 2006 05:54 AM
pro amplifiers vs. home audio amplifiers bonsai171 Solid State 26 25th February 2004 08:24 PM
Paradigm amplifiers? Anthem amplifiers? Corn-Picker Solid State 2 24th January 2004 03:10 AM
Many smaller amplifiers vs. bigger amplifiers. djdan Solid State 9 17th September 2002 04:40 PM


New To Site? Need Help?

All times are GMT. The time now is 01:00 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2