Do I need more testing gear?

Thread Starter

DraxDomax

Joined Apr 5, 2019
39
Hi, I am just starting. Right now, I am going through the books available here but I am also fooling around with the breadboard and stuff.
I have a cheep multi-meter that helps me a lot to confirm theoretical situations when I am learning about voltage, resistance and current.

However, I do read about "osciloscopes"? I think these are devices that measure wave form as a part of studying AC electronics.

My ultimate interests are battery and power applications but I think some playing with audio and radio is inevitable! :) (and important
to my understanding of electronics, of course).

Do I need an oscilloscope or other gear?
 

Thread Starter

DraxDomax

Joined Apr 5, 2019
39
It all depends how deep you go into stuff.
For a cheap 'scope you can use a PC and free software. This also gets you a spectrum analyser.
For instance: https://www.zeitnitz.eu/scope_en
That's a pretty nice case of repuroposing what you got instead of buying more stuff.

However, I am not sure I can pull this off on my laptop:
1. I only have 1x3.5mm jack, which I think is output only.
2. I am scared to fry my laptop. It's an on-board soundcard.

BTW, will this read different wave shapes? I recall seeing waves that look "rectengular" and other waves that look "triangular". I thought all the sound card cares about is frequency?
 

Wolframore

Joined Jan 21, 2019
1,256
YES! Don't ask my wife... more... more better...

You can get some toy oscilliscopes online for about $20 as a kit... would be informative and would work fine for audio....
 

AlbertHall

Joined Jun 4, 2014
8,358
That's a pretty nice case of repuroposing what you got instead of buying more stuff.

However, I am not sure I can pull this off on my laptop:
1. I only have 1x3.5mm jack, which I think is output only.
2. I am scared to fry my laptop. It's an on-board soundcard.

BTW, will this read different wave shapes? I recall seeing waves that look "rectengular" and other waves that look "triangular". I thought all the sound card cares about is frequency?
You might get an old desktop for nothing/peanuts then you don't need to worry about frying the soundcard,
 

rsjsouza

Joined Apr 21, 2014
201
You can get by without an oscilloscope - I only got one 15 year after starting as a hobbyist.

However, as Wolframore mentioned above, the cheap kits allow you to get started with a very basic but still functional oscilloscope for your learning purposes. I provide some suggestions at this link.

Although tempting, using your only laptop for this is way too risky. As mentioned by AlbertHall, you will have to get a spare PC.
 

Wolframore

Joined Jan 21, 2019
1,256
Actually I need one of these "toy" ones for when I do transient testing in field... need to just trigger and records for about a 100 millisecond to 1 sec max... anyone have a suggestion? Don't care if it's not pro... just gotta work and give me decent results. since its a DC pulse freq doesn't matter. Cheaper the better... i won't cry if I destroy it...:D
 

Thread Starter

DraxDomax

Joined Apr 5, 2019
39
So, does the software scope detect different wave shapes or it just reads the peaks and assumes it's a sine?

Also, is there other gear I might need? I've also heard about logic analyzers?
 

AlbertHall

Joined Jun 4, 2014
8,358
So, does the software scope detect different wave shapes or it just reads the peaks and assumes it's a sine?

Also, is there other gear I might need? I've also heard about logic analyzers?
Software scopes, just like hardware scopes display the waveform of whatever signal you feed to it.
Essentially the display is a graph of voltage against time.
 

Wolframore

Joined Jan 21, 2019
1,256
Oscilloscope is a great place to start. You can see logic levels with them. Once you get more specialized in different areas. Spectrum analyzers and sig gens but some scopes come with limited features on some models.

Basics is multimeter and power supply. Everything else is more advanced. You can get far with ohms law and a good multimeter.
 

SamR

Joined Mar 19, 2019
1,149
In order of "need/want":

Digital autoranging MultiMeter (<$50)
Bench DC power supply (~<$100) (or a breadboarded LM317 1.5A, 1.2V TO 37V ADJUSTABLE VOLTAGE REGULATOR or kit <$20)
Signal generator (<$100)
Oscilloscope (<$700 depending on what you want, used cheaper)

A/C power supply (use 240/120/12/6VAC stepdown xfmr properly fused and grounded <$50) w/ added rectifier, filter, and adjustable regulator you also have DC pwr.

Scope handy and useful even w/o signal generator.

Prices vary w/ quality, features, and precision. This is just a starting point for consideration...
 

rsjsouza

Joined Apr 21, 2014
201
Actually I need one of these "toy" ones for when I do transient testing in field... need to just trigger and records for about a 100 millisecond to 1 sec max... anyone have a suggestion? Don't care if it's not pro... just gotta work and give me decent results. since its a DC pulse freq doesn't matter. Cheaper the better... i won't cry if I destroy it...:D
That will always depend on the sample rate you need to capture the transient. The two cheap ones I see from JYE Tech that have a buffer are the DSO068 and the DSO094. Otherwise you can always try to get by with a somewhat cheap Data Logger or a DMM with Data logging.

Also, is there other gear I might need? I've also heard about logic analyzers?
Logic analyzers are very useful for when you need to track pure data communications between a microcontroller (Arduino, for example) and an external device (a temperature sensor, another microcontroller, a serial port with the host PC, etc.). Since you are unsure you need one, then you probably don't at this time. Otherwise, check the Kingst LA1010 as a very well rounded low cost option with good software.
 

Yaakov

Joined Jan 27, 2019
1,541
So, does the software scope detect different wave shapes or it just reads the peaks and assumes it's a sine?

Also, is there other gear I might need? I've also heard about logic analyzers?
An oscilloscope, fundamentally, does something very simple: it shows voltage over time. A line sweeps across the display at a particular rate and the input moves the position up or down based on voltage. The rest is enhancements to this idea.

A sound card can measure instantaneous voltages with its ADC (Analog to Digital Converter) and by plotting these values over time on the display, an oscilloscope can be created. It's that simple.

There are PC-based oscilloscopes that use external boxes to do the work of collecting data and USB to the computer to display it. This might be a good choice for a starter. On the other hand, for $300-$400 you can get a dedicated instrument of surprising quality that can do much more, so, you have to decide how committed you are.
 

Reloadron

Joined Jan 15, 2015
4,508
The amount of test, measurement and diagnostic equipment you need is directly proportional to what you plan to be doing with it. Things like a scope run from being a nice to have to being an essential piece of equipment. When considering an oscilloscope sit down with a pencil and paper, a pencil with a large eraser is preferred and start listing what features you want or need as well as nice to have. Allow room for expansion of the want list because once you buy, what you have is what you have. Older very good analog scopes can be had used for a few hundred US dollars, I have a few older Tektronix scopes I still use. Several members here have recently invested in some nice new digital scopes in the well under $500 USD range. With careful shopping you get what you pay for.

Ron
 

BR-549

Joined Sep 22, 2013
4,936
I never thought about it, but Albert has a good point. A dedicated bench computer(even second hand) would be an excellent tool, or a toolbox, for many other tools.
 

MrChips

Joined Oct 2, 2009
19,273
If you don't know what an oscilloscope does then you do not need one.

You are already doing well with a basic DMM and a soldering iron. That's all you need for now.

Wait a few more years. By then you will find out what you really want (not need).

(and a few more years down the road you will come to really want an oscilloscope, a function generator, and a variable bench power supply...$$$)
 

SamR

Joined Mar 19, 2019
1,149
or other gear?
Start with a BENCH! A place to work, good lighting, comfortable seating, durable nonconductive bright surface, room for equipment and parts, storage drawers, power connections, shelves, and books. Those are some of the things I had before I started buying expensive electronics. The rest will come later when you need it and have room for it.
 
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