Home DIY Electronics

GP's Comment

Thu, 10 Nov 2022 03:19:51 +0000

I've wanted to have a scope show NTSC video on screen in a raster but never tried it. Now retired don't have access to a scope. It would be nice to add a Z access to this program for showing an image. would probably use the Mic input. I can make a rectangle show using square wave from the generator but see where people make sync separators and create sawtooth signals. A few places I had access to nice signal generators. Was always too busy to play around. Thanks for this program.

MikeF's Comment

Mon, 22 Oct 2018 12:42:13 +0100

Scope works perfectly in Linux under WINE. For safety use an external USB sound card (very cheap), and select the new card in the Sound settings. A far greater value can be chosen for the input resistor, say 100k ohm plus, and the diodes can be doubled (in series) to give slightly greater range.

Don Burke's Comment

Mon, 30 Apr 2018 00:23:58 +0100

3 years and no answer! Just skipped over! Don't waste your time asking a question if you are just learning. They will just pass over it.

Eleguru's Comment

Sun, 29 Apr 2018 07:38:07 +0100

It's really an awesome idea. Not only one will save a tremendous amount of money but also gain a lot of knowledge. Thanks for sharing!

Radu's Comment

Tue, 30 Jan 2018 17:25:00 +0000

Great project , i have some questions if you don't mind . What is the maximum audio voltace i could apply to the measurement probes,i i were to test lets say a 30 w rms amplifier , is it possible ? If it is possible what should i do , some extra circuit ? And second question what is the max bandwith , like 20 Hz ... 2o KHz . Thank you and all the best from Romania !

Aidan's Comment

Sat, 02 Dec 2017 17:15:27 +0000

can it handle ac current

venturini patrick's Comment

Mon, 04 Sep 2017 21:12:07 +0100

Hello Thanks for your video . Beccause , befor having enough money tu by a osciloscope , i will try to build the litlle osciloscope .
But cant find the link ( lin adress ? ) tocharge on the computer ( for simulating the 2 channels of a osciloscope ).?
Could you answersto my mail adress ?
Thank
Your
Bes t regards
Patrick Montpellier France

Novalar's Comment

Tue, 22 Aug 2017 20:40:30 +0100

Good article!

Novalar's Comment

Tue, 22 Aug 2017 07:57:13 +0100

Thanks! I used this to measure a laser driver stability when switching the current, I was able to see the switch spikes perfectly!

Dan's Comment

Fri, 30 Jun 2017 21:05:31 +0100

Can the scope described in the book work with a Linux based software?

Sam's Comment

Sat, 09 Apr 2016 07:33:58 +0100

Hi, this is an amazing idea and this is going to save me a lot of money. I have not yet built this circuit. I have a few questions to get cleared.
1. To which port of my do I connect the output probe to? headphones or microphone or line-in?
2. For my experiments, I may have to operate around a voltage of 15 to 22 volts. Will this pose a threat to my sound card?

Steve's Comment

Tue, 05 Apr 2016 09:15:48 +0100

Hi Dave,

Yes this should work fine providing that you stay well away from the high voltage part of the engine. That will be the spark plugs and induction coil etc. It should work ok for sensors that are likely to be 12v powered. Always Test the signals with a multimeter first. Test for DC voltage and AC voltage and do not use the scope on anything over 30v.

Steve

Dave's Comment

Fri, 01 Apr 2016 10:20:35 +0100

Hi, thanks for sharing this build, it's great.
I want to make this oscilloscope to test sensors and wiring on my car, but the cars voltage is between 12v and 14.4v.
Will this work for me?
Or, are there any changes that I can make to the design so that it will cater to my needs?

Thank you.

Steve's Comment

Sun, 31 Jan 2016 13:44:00 +0000

Hi David,

I do believe that you can store a single sweep. You can set it for single sweep and get it to trigger somewhere of interest.

Steve

David Schroeder's Comment

Thu, 21 Jan 2016 22:14:48 +0000

Is it possible to store a single sweep with this system? Currently I have a Textronix 465B scope, and my experiment setup entails a single sweep for each run, triggered by a specially timed pulse. It's hard to analyze any detail as the image on the screen is so transient. Being able to capture a single sweep and continuously display it would be really useful.

David Schroeder's Comment

Thu, 21 Jan 2016 22:14:36 +0000

David Schroeder's Comment

Thu, 21 Jan 2016 22:09:59 +0000

Is it possible to store a single sweep with this system? Right now I have a Textronix 465B scope, and my experiment setup entails a single sweep for each run triggered by a specially timed pulse. Currently it's hard to analyze detail as image on the screen is so transient. Being able to capture a single sweep and continuously display it would make it really convenient.

Steve's Comment

Sat, 12 Dec 2015 17:26:28 +0000

Hi Keerthana,

In theory you could build a phase locked loop by adjusting the output waveform from the headphone socket in real time depending on the waveform input through the microphone input.

I'm not aware of any PLL software for the pc so you would need to write some code to do it. This is way beyond the scope of this article unfortunately.

Steve

Keerthana's Comment

Sat, 12 Dec 2015 16:12:58 +0000

can we implement a phase locked loop using sound card

adil's Comment

Tue, 17 Nov 2015 14:19:37 +0000

instead of pc can i use android based cell phone(smart phones)... you find many app in play store can this circuit support any one can help me out!!

adil's Comment

Tue, 17 Nov 2015 14:17:41 +0000

instead of pc can i use android based cell phone(smart phones)... you find many app in play store can this circuit support any one can help me out!!

Steve's Comment

Sat, 29 Aug 2015 17:44:20 +0100

Hi Saurabh,

The trigger pulse of the HC SR-04 is a minimum of 10 micro seconds which will not be easy to see with the sound card oscilloscope with a maximum bandwidth of 20kHz. However the trigger pulse doesn't have to be that fast.

I used a trigger pulse of 50us in the project that I published on the site. At 50 micro seconds the pulse is just detectable by the scope. It won't look very square of course but you can detect it's presence which is usually what you want to see. You can extend the trigger pulse more if you want it to look better on the scope.

The echo pulse is measured in the 10s of milliseconds which is easily viewed using the oscilloscope.

Hope this helps
Steve

Saurabh's Comment

Sat, 29 Aug 2015 13:21:06 +0100

Hi Steve :)
Can I use the above PC Sound Card based oscilloscope to display the ECHO & TRIG waves of an Ultrasonic Sensor Module(HC SR-04) ?
I see under your other project(s) on this website you are using HC SR-04; So I assume that you are better aware of the details for the same.

Regards,
Saurabh

Steve's Comment

Sat, 04 Jul 2015 14:29:29 +0100

Hi Pokke,

Using an electrolytic input capacitor is not a good idea. Worst case the capacitor could explode if you apply voltage in the wrong direction.

It is more than possible that you will be applying AC signals to the probe that swing both '+ve' and '-ve' which may cause the capacitor to malfunction.

Electrolytic capacitors work best when there is a DC bias across them. The terminal marked with a '+' should always be positive with respect to the '-ve' end. Electrolytic capacitors are easier to manufacture with high capacity and are generally used to smooth the output of power supplies and other other things.

You need to use a non-biased, non-electrolytic capacitor in this instance.

Steve

Steve's Comment

Sat, 04 Jul 2015 14:13:59 +0100

Sorry for the delay in replying. Auto ignition systems generate many thousands of volts and even one turn of wire around the ignition lead could induce very high voltages. For this reason I would say do not attempt this unless you are very confident that you know what you are doing. Worst case you could damage both the probe and your PC.

Steve

Pokke's Comment

Mon, 29 Jun 2015 22:32:27 +0100

I just made a scope semi following your schematic from the book but used electrolytic 1uf caps and a 5k pot.
it seems to work right. I have been meaning to ask what the difference is between the poly box ones you use and the ones I used.
still much to learn, but having a great time with your book so far. now on to building the cali/generator. thanks Steve

Don Burke's Comment

Sun, 24 May 2015 03:37:09 +0100

Could you clarify a few things? I was looking at the one that Make did that is a copy except for the values and yours. There are 3 wires for the input and 3 for the output. So one is common on the input and one on the output. Your diagram shows 4 inputs and 3 outputs. on the input, I am guessing the v1- and v2- are the common ground. On the output, I am guessing the same is true, v1- and v2- are common ground and the v1+ and v2+ are separate on the plug to the sound card. Which pin on the output goes to what wire? Is the tip the negative and the other 2 side pins the 2 channels? Does it make any difference that the make resistors were a different value then the ones shown here? Thanks for the design. I await your answer. (don't want to blow up the computer)

mike baker's Comment

Thu, 30 Apr 2015 09:52:22 +0100

Hi Steve,

Would this be suitable for reading a signal going to a moped tachometer?

The cable is wrapped around the spark plug wire.

Many thanks,

Mike

Steve's Comment

Tue, 07 Apr 2015 09:34:22 +0100

Hi João,

I'm very sorry that you are having a problem. Having just done a little research there appears to be some kind of copyright issue going on with Amazon purchases of ebooks in Portugal. I have no idea what it could be.

Some people have had success by buying from the amazon. com or . co. uk sites. You might want to try that. If you still have a problem then send me a message using the contact form (link at the bottom of this page) and I will see what I can do to help.

Regards
Steve

João Alves's Comment

Tue, 07 Apr 2015 08:30:16 +0100

Hi Steve!

Unfortunately Amazon tells me that your book is not available for my country (Portugal).

I wonder if there is any other way to get it.

Thank you.