Beginner Looking for suggestions! - Page 1
Forum section: electronics / beginners

author: Adgj533
author_rank: Contributor
timestamp: February 21, 2018, 04:08:53 pm
content: Hey I am new to the electronics world, I am looking for setting up a work bench at home and I have a budget of around $500.Can you experienced members give a list of products i should buy?I def need 1) scope 2) function generator 3) power supply- i want to build this so i need 4) soldering iron+solderi already have a breadboard kit which includes resistors, caps,ind,diodes etcbut I need few suggestions for 1,2,3 and 4.Links would be useful.Highly appreciate all the help, Thanks and this is such an awesome websiteCheers

author: Raj
author_rank: Frequent Contributor
timestamp: February 21, 2018, 04:30:29 pm
content: what field of electronics?tube era/high voltage?digital?analogue?repairs and restortion?

author: rstofer
author_rank: Super Contributor
timestamp: February 21, 2018, 04:47:28 pm
content: Well, the scope is easy (assuming you are not working on RF or very high frequencies) = Rigol DS1054Z is very popular and affordable at $349 at TEquipment.https://www.tequipment.net/Unlock it, details elsewhere, and you have 100 MHz, plenty of memory and all the options that are already included. A lot of bang for the buck.But that only leaves $150 and you won't get a quality signal generator for that kind of money. Why do you need one? I managed to get along for 40+ years without one and bought one last year just because I could. Of course, I do mostly digital and there are other ways to generate signals.You could try the FG085 for a while. It's not the cleanest output in the world but it's not bad.https://www.sparkfun.com/products/11394OR...You could just get the Digilent Analog Discovery 2 with all the options and get along quite nicely. You have to promise not to probe mains voltages and pay care to the limitations but this is a great device for a student/newcomer. Dual output signal generator, dual channel scope, digital input/output and logic analyzer plus an array of virtual instruments. You can do stuff with the AD2 that takes a barn full of discrete tools.https://store.digilentinc.com/analog-discovery-2-100msps-usb-oscilloscope-logic-analyzer-and-variable-power-supply/https://store.digilentinc.com/analog-discovery-2-pro-bundle/Download the software and play with the Demo device. Just look at the different virtual instruments. There is simply nothing like it, anywhere!If I were starting out and on a budget, the Analog Discovery 2 is the approach I would take. It is literally a lab that fits in a backpack. Besides, 27" screens are bigger that 7" screens on real scopes. Don't overlook the portability of this gadget. It's easy to carry it along with a laptop or Surface tablet. For certain, the gadget works on my Surface Book!

author: rhb
author_rank: Super Contributor
timestamp: February 21, 2018, 05:22:15 pm
content: Whatever your budget and choice there will be things you don't like. The DS1000E/Z Rigols have crappy FFTs. The Instek GDS-2000E has great FFTs, but no vernier vertical adjustment which the Rigol DS1102E does (and I assume the Z also).The JDS6600 and FY6600 AWGs are quite good for the price. There's a long thread on the FeelTechs which have a FW corruption problem in FW versions below 3.2. Both use ungrounded SMPSs so they can have large voltages on the BNC ground sleeve. I measured 176 Vpp on mine. I fixed it by adding 1 nF from the instrument ground to the ground of a 3 wire plug I installed. Tested it for several hours on the bench and it worked great. Next day I turned it on and the FW was corrupted. However that seems to be fixed in V3.2.1. Unfortunately that does not help me as FeelTech made lots of promises of support but has never fixed the problem for anyone on the forum who has been affected.I had the good luck to get an Instek GDS-2072E from Amazon for $244 delivered when they disposed of old stock. But that was a fluke. I've had a DS1102E for 3-4 years and have been quite pleased with it. At $400 I think it was a good buy. I've also got an Instek MSO-2204EA which cost over 3x your budget. The Insteks will do a million point FFT and with a bit of fiddle you can use it as a spectrum analyzer. I had intended to buy a Rigol DS1104Z-S, but didn't because of the FFT.The Rigol DS1054Z is very popular and has a good track record despite its limitations. It is also quite aggressively priced and widely sold. You can "hack" it to say it is a 100 MHz scope, but I'm very skeptical that a hacked scope meets all the specs of the DS1104Z.You want to watch out for input limitations. All 2 prong SMPS have the mains voltage on the ground problem. So the 300 V input limit on a proper DSO such as the Rigol might well prove important as you can have leakage where you don't expect it.There are scads of reviews on the sort of kit you're looking for. Rather than take anyone's recommendation I suggest investing the time to watch and read all the reviews of kit in your price range.That said, I don't think you'd go wrong with the DS1054Z so long as you don't expect it to become a 100 MHz scope just because the screen says it is. With the serial decode options for free now it's a remarkable deal.One final comment. Research and pick a scope. Then build a power supply from scrap. Lots of older audio gear has linear power supplies with transformers which you can use to build an adjustable PS using an LM317. Thrift store get this sort of thing in all the time. They test the stuff and if it doesn't work it goes in the trash. You can probably negotiate all that stuff you have room for a dollar or less if you ask the folks who check the gear. In grad school I fishd audio gear out of the trash and fixed it using nothing bu a VOM.You can get a DMM from Harbor Freight for free if you have the right coupon when you buy yourself a set of pliers. They're not great, but that's actually what I use 90% of the time. They're only 1 Megohm input impedance, so there is some loading relative to an 11 Megohm meter, but it's minor compared to a 50 Kohm VOM. You rarely care if it's 3.3277 V. You care if it's between 3.2 and 3.6 V. Typically your parts are going to be 5-20% of the marked values. Good design accommodates that.If you're interested in audio gear a PC soundcard will prove an excellent signal source AND spectrum analyzer with the aid of some scripts and Octave or MATLAB. A square wave generator made up of a fast op amp and a few other parts will give you an excellent audio test signal for under a dollar as a bare board and 2-3x that if you put it in a box.For a good project, read "Max Wein, Mr. Hewlett and a Rainy Sunday Afternoon" by Jim Williams. Use a soundcard and Octave to do the THD measurements.An interesting aspect of this is that the more you know, the less you need for the majority of use cases.Have Fun!Reg

author: Lightages
author_rank: Unknown
timestamp: February 21, 2018, 05:24:48 pm
content: Have a look at this old thread for ideas:https://www.eevblog.com/forum/beginners/the-$250-electrnoics-lab-a-suggested-setup-for-beginners/and Dave's video:

author: Ordinaryman1971
author_rank: Frequent Contributor
timestamp: February 21, 2018, 06:34:11 pm
content: Buy multimeter first, pick your favorite. Buy soldering iron, get a nice one, Hakko, Weller or even one of the Chinese giants, like Yihua.Buy broken power supply on ebay, buy it dirt cheap so if you won't fix it it won't bring you to tears.Fix it, try to fix it, fix it again, fail, fix it, fail, fix it again and finally get it fixed. If you run in the troubles, have a friend to help you, ask here....Now, you have a meter and a power supply that's hopefully working, if not take it apart, now you have few odd parts, few of them could be even good... if the power supply was to stubborn to be resuscitated buy another one and try to fix it.If you were able to fix the power supply, buy a signal generator.... if you still feel you need one. Buy a broken one and.. fix it.Repeat the process, borrow a scope from your friend.. if he doesn't have a scope, get another friend, lol.Then, if you are still interested in electronics, and it's not boring to you, and to hard, and to time consuming, and you didn't burn your house down....Buy another meter... maybe a bench multimeter, buy it broken and fix it.I think you need a second multimeter before you need a scope...Repeat and rinse and repeat again.Before you know it you will be 60 year old and retire as an EE, then buy a scope.

author: rstofer
author_rank: Super Contributor
timestamp: February 21, 2018, 06:36:17 pm
content: Quote from: rhb on February 21, 2018, 05:22:15 pmThere are videos all over the place demonstrating WHY the upgrade works and also demonstrating that the new 3 dB point is about 130 MHz, well over the 100 MHz claimed.Do a search in the Test Equipment forum - there are a couple of epic threads so do a proper searchHere's a poor place to start:https://www.eevblog.com/forum/beginners/rogol-1054z-actual-bandwidth/msg1380773/#msg1380773Dave did a video showing how Rigol has two separate input filters - one for 50 MHz and one for 100 MHz and they are selectable by firmware. Same scope, two filters. It's cheaper to manufacture one scope with two filters than it is to manufacture two scopes.There is no debate, it just works and has been proven to work.

author: Adgj533
author_rank: Contributor
timestamp: February 22, 2018, 03:33:22 am
content: Hey guys, thanks for all the amazing input/suggestions. I decided to buy rigol scope and yihua 936 soldering kit but for the function generator, i found one on amazon heres the linkthihttps://www.amazon.com/Longruner-Dual-channel-Function-Generator-Precision/dp/B06VTQQ5QX/ref=sr_1_10?ie=UTF8&qid=1519269193&sr=8-10&keywords=function+generatoris that a good function generator to buy?Also I forgot to mention, I am an EE major so its not really a hobby, Im gonna be working in the field. I usually do labs at school but I felt that I wasnt learning a lot so I decided to set up a small lab at home.

author: rstofer
author_rank: Super Contributor
timestamp: February 22, 2018, 04:25:09 am
content: It should serve you well for a long time.Congratulations on the EE program. It's a lot of work and having a lab at home will be a big help. I always learned more by doing that by reading or listening to lectures.

author: Adgj533
author_rank: Contributor
timestamp: February 22, 2018, 05:58:18 am
content: im really scared of blowing shit up or destroying my scopes, any suggestions>?

author: hamster_nz
author_rank: Super Contributor
timestamp: February 22, 2018, 08:20:59 am
content: Quote from: Adgj533 on February 22, 2018, 05:58:18 am1) Don't go near anything that may have lethal voltages until you know what you are doing (e.g. anywhere near a 110/220V switch mode power supplies, even when turned off)2) Remember that your scope's chassis will be solidly grounded, if you connect the probe's ground lead to things that should not be grounded, then bad things will happen.3) Maybe get a fixed 10x probe and use it in preference to a switchable 1x/10x. You can then make a 10x bigger mistake before you kill your scope's front end (i.e. a +/-25V front end will not be destroyed if you accidentally probe 60V, because it will be attenuated to 6V by the 10x probe)4) Never leave your red multimeter probe plugged in the A or mA socket. It is so easy to forget this and blow things up!

author: Old Printer
author_rank: Frequent Contributor
timestamp: February 22, 2018, 01:59:57 pm
content: Quote from: Adgj533 on February 22, 2018, 05:58:18 amHere is Dave"s epic video on how not to blow up your scope, probably the most recommended of his vids I have seen here.He also has a 3 part set on soldering, not a five minute watch, but none of his are.Older analog function generators are all over ebay for $30-50. They will give you a reliable set of basic signals to feed your scope and projects. This guy always seem to have some and is a good vendor, but look for one close to home to keep shipping costs down.http://myworld.ebay.com/pb126100/Best thing you can do is read, read and read some more, then draw your own conclusions. I could not pick which low price scope to get so I bought the Analog Discovery with BNC board $300. Not cheap, but great software and a good variety of basic tool for a beginner. I love it. And grab an old analog scope if you can get one cheap, nice to have both views. Dave has a good video on this subject as well. Welcome!

author: rstofer
author_rank: Super Contributor
timestamp: February 22, 2018, 03:08:26 pm
content: Quote from: Adgj533 on February 22, 2018, 05:58:18 amSo, work at low voltages on small ampacity circuits. Things fed by wall warts or batteries.The pesky ground clip on the probe is the whole problem. Make sure you know where to connect it. It isn't just your scope you need to worry about. Many projects have USB ports and the port on a PC is grounded. You really don't want to wipe out your PC.hamster_nz has pointed out a potential hazard with the common DMM. Make sure, before every measurement, that you know which scale to use and that the probes are in the correct location. Better meters will warn you if the probe is in a current jack and the selector is set for voltage. This is a really BIG DEAL! I saw the results of a Simpson 260 VOM after it was misconnected to 480VAC - it became a hand grenade. Nobody was seriously hurt but they didn't' work out of their pay grade ever again.I like low voltage, low energy, circuits.

author: rhb
author_rank: Super Contributor
timestamp: February 22, 2018, 11:25:11 pm
content: Quote from: rstofer on February 21, 2018, 06:36:17 pmWas that because mine was the last post?If you know of a video or post that does a comprehensive test I'll be happy to look at it. But I'm not going to waste my time watching hours of YouTube looking for evidence to prove *your* assertions. Nor am I going to read through epic threads.Bandwidth is just one of many important parameters. Would you buy a scope that was +4 dB at 80 MHz? If you were selling scopes and trying to establish a reputation would you ship that as a 100 MHz scope because it wasn't -3 dB until 135 MHz? I certainly wouldn't. I'd incorporate a software selectable RC filter in the design and units that tested out of spec I'd configure to be in spec.And what about the 70 MHz models?If it sounds to good to be true, it probably is. You can't con an honest man.

author: Lightages
author_rank: Unknown
timestamp: February 22, 2018, 11:33:25 pm
content: Must every thread started by a beginner devolve into a pissing contest? If you want to fight about scopes, go fight somewhere else.

author: Jwillis
author_rank: Super Contributor
timestamp: February 23, 2018, 12:22:04 am
content: Welcome to the electronics world.It says in your post you have a budget of $500.Well fact of the matter is your not going to the best but you can get started.Occasionally you can find used equipment on Ebay but it probably is uncalibrated with a questionable life expectancy.If you have a computer, A Hantek 6022BE sells for under $100, not the greatest but enough for a beginner.A Atten ATF20B DDS Function Generator for under $250 these work pretty good. Avoid the Feeltech brand .There has been issues about the power supplies leaking high voltage out the front end BNC connections.Switch mode Bench power supplies can be under a $100 for a 10amp 30 volt adjustable.Theirs a lot of good deals and some are even reviewed and demonstrated on you tube

author: rhb
author_rank: Super Contributor
timestamp: February 23, 2018, 06:26:02 am
content: I think it does a novice a real disservice to encourage him or her to think that BW is the only figure of merit in an oscilloscope which is precisely what promoting the idea of "hacking" a DS1054Z to think it's a DS1104Z does.Take a look at this:https://www.eevblog.com/forum/projects/yet-another-fast-edge-pulse-generator/msg1432180/#msg1432180at these bandwidths that pulser produces a step which is *perfect*. The rise time for mine was measured at 39 pS. The scope trace plots that came with mine don't even last 1 nS. If you have any doubts look at the posts of step responses from 1+ GHz instruments in the thread. So what you see in my plots is the scope response to a perfect step while sampling at 1 GS/S.I don't like either of the Instek step responses. The MSO-2204EA has too much overshoot and the GDS-2072E is just plain ugly. The Rigol is the only one that I find acceptable. I happen to agree with R&S that the step response should be Gaussian, but lots of people prefer the Rigol response. And when I repaired and calibrated my Tek 465 and my Dumont 1060 (60 MHz) I adjusted them to the step response shown by the Rigol because that's what the manuals said to do using a Tek 106 pulser.I've spent several hours today working on packaging a Zybo Z7-20 and a BeagleBoard X15 into an old computer case in preparation for doing some serious DSO hacking. I bought the 2072E solely for use as a test bed. I am not going to risk bricking my MSO-2204EA. The Zybo and BeagleBoard are development tools. I'm not trying to circumvent OEM FW. I'm working on writing FOSS that will run on Zynq based DSOs that does what I want. One thing will be to implement a digital filter to clean up the step responses of the Insteks. Yes, it will take a while. But it's really pretty trivial compared to the kind of DSP programming I did in the oil industry for 20+ years. A lot of that stuff takes a year or two to write working full time. And the math is a *lot* uglier than anything in a DSO. Though I'm looking to change that by implementing compressive sensing ;-)With regard to the FeelTech comment by @Jwillis, I certainly suggest caution as FeelTech customer support is non-existent. I have one. It borked itself the day after I fixed the PS by adding a 3 wire cord and caps to ground the leakage voltage. But *all* SMPSs that do not have 3 wire grounded plugs have the same problem which is caused by the Y caps required for EMI suppression.Finally, why does a novice need a 100 MHz scope? They got to the moon using 50 MHz Tek 547s.https://www.tek.com/blog/comparing-apollo-era-workhorse-today%E2%80%99s-bench-scopeA good 50 MHz scope is far better than a dubious 100 MHz scope. While I've not used one, I feel pretty comfortable saying that the OP is unlikely to experience buyer's remorse buying a DS1054Z with the included serial triggering options on the basis that it is a good deal on a 50 MHz 4 channel DSO. Twenty years ago I paid almost that much for a 20 year old Dumont dual trace 60 MHz scope that died a few days after the 30 day warranty ran out.

author: Adgj533
author_rank: Contributor
timestamp: February 24, 2018, 05:08:34 am
content: I will try to make better titles, srry about if the title was mis-leading, it was my very first post so i wasnt aware of it.But the community here is great and the responses were pouring in.I have to build a low distortion audio power amplifier for school and i have the schematic already.I dont get some parts of it, is it wrong to ask for help bc its a school project? I dont want anyone to do the project for me, i def wanna learn on my own but that being said some pointers would def help. Also this goes to everyone, please give your input on thisThanks again, Appreciate all the help you guys are awesomeCheers

author: rhb
author_rank: Super Contributor
timestamp: February 24, 2018, 05:30:00 pm
content: Quote from: Adgj533 on February 24, 2018, 05:08:34 amIt's certainly not wrong to ask questions. The thing that is annoying is people wanting someone to do their homework for them.You are going to need a way to measure the distortion. Traditionally you would use an HP audio oscillator and distortion analyzer. The Wein bridge oscillator was Bill Hewlett's MS project at Stanford. His thesis supervisor suggested the idea which worked so well he encourage Hewlett to manufacture them.Look for "Max Wein, Mr. Hewlett and a Rainy Sunday Afternoon" by Jim Williams. I think you'll find that is a nice follow on project.In the mean time, you are going to need a way to measure the distortion. MATLAB or Octave and a sound card are the best option. If it's not already obvious, you will need to generate a WAV file with a 1 KHz sine wave and play it through the sound card line out while recording it on the line in using a cable from output to input. That will allow you to determine the errors in the sound card input and output.Then repeat the measurement with your amplifier in the circuit with a suitable attenuation pad. Load the output into MATLAB, compute the amplitude spectrum, normalize by the amplitude spectrum with just the cable and then sum up the harmonics and divide by the fundamental.If you've already had a course in linear systems this should be trivial. If not post or send me a PM and I'll explain the fine print details.With regard to the start of this thread, as you are an EE student, you should be able to arrange lab time to test personal projects for which you don't have the test gear needed. That makes building test gear a lot easier than it was for me. My first degree was English lit, my second was geology, so I couldn't get in the EE labs and only had a recurrent sweep 5 MHz Heathkit scope I picked up at yard sale for $75. But it was enough to build and test a linear 5 V supply for TTL and repair a 12 V supply I bought for $1.For a signal source I used a quasi square wave generator using an op amp. I don't think I ever added a TTL divider to make it truly square. I had great fun building a 120 dB 3 transistor DC coupled amplifier. At the time I was obsessed with building a 40 M xcvr to fit in a cigarette pack (this was 30+ years ago when it was hard to do). So the 120 dB amp was built on about 1" square on perfboard. And it oscillated like mad at 200-300 KHz. I studied the circuit and decided that the problem was the electrolytic bypass capacitors which have significant inductance. So I added some small ceramic caps in parallel and after that design change it worked just fine. I was quite proud of myself for figuring that out as I'd never taken an electronics course. And still haven't. The closest I got was listening to lectures as a break from looking through a microscope all day at thin slices of rock for my thesis project.120 dB is a *lot* of gain. With a small speaker hooked up the output I could listen to a nearby FM station just by holding a finger close to the input terminals by means of slope detection.FWIW you could build a quite high performance audio test bench around a Raspberry Pi or similar. You'd have to write custom software, but it would not be hard as the difficult stuff like the FFT code is widely available. There are easy ways to increase the dynamic range of the measurements far beyond what the ADC in the Pi will do using DSP.Have Fun!And if you have a masochistic streak, try to build a sub-nanosecond rise time pulse generator for testing scopes using a 10 MHz clock module and a fast logic driver for the output. It's a lot harder than it might sound. But there are some really good suggestions for the output in various forum threads.

author: rstofer
author_rank: Super Contributor
timestamp: February 24, 2018, 05:46:25 pm
content: Quote from: Adgj533 on February 24, 2018, 05:08:34 amLife is an open book exam, ask away! It will still be your work and your grade so choose your resources carefully.Post the schematic, let the more knowledgeable people take a look at it. I'm not into audio so I'm no help but there are a number of others with a great deal of experience.

author: Adgj533
author_rank: Contributor
timestamp: February 25, 2018, 01:02:19 am
content: I made a different thread on the correct section for the audio amplifier i want to build, I wasnt sure if i should post it here or therebut heres the linkhttps://www.eevblog.com/forum/projects/low-distortion-audio-power-amplifier/

author: Adgj533
author_rank: Contributor
timestamp: February 25, 2018, 02:03:49 pm
content: I saw the video of daves how to NOT blow up ur scope, idk if I get the concept correctly.So the problem is if you connect power supply ground to the same ground as scope and if the PSU ground is also earth connected, BIG BLAST?I also had a question, what if scope gets a separate ground and the PSU ground goes with circuit ground? would that be a problem or the scope wouldnt work then?When in lab, I usually connect all the grounds as 1 ground but since now I have scope at home, I dont wanna make that mistake at home.Thanks for your feedback, highly appreciatedCheers

author: Old Printer
author_rank: Frequent Contributor
timestamp: February 25, 2018, 03:52:02 pm
content: I just re-watched Dave's "Don't Blowup Your Scope" video that I had recommended to you. That is pretty basic stuff, so if it does not make the situation clear on it's own I would tell you to put your probes away for a while and keep reading until it does. It is all about the possibility of creating a dead short. Merely connecting your scope, PC and DUT grounds together does NOT create the BIG BLAST you mention, but it does make that possible "IF" you connect a source of substantial current in any of the chain to that ground. If the current source is not high enough to injure you it could still be enough to ruin some or all of your equipment.

author: Adgj533
author_rank: Contributor
timestamp: February 25, 2018, 06:25:26 pm
content: Quote from: Old Printer on February 25, 2018, 03:52:02 pmso its only if u connect a red lead from PSU to ground when its connected to other ground, the damage happens? for example lets say i have a simple circuit and i have 1 ground for scope and psu and circuit, so if i accidently connect the +15V or -15V (PSU Being 30V/5A)to the ground, it can damage the equipment?I have done a lot of labs, never had this happen but I just wanna make sure I know how it happens so to avoid it.Could you give an example with a simple circuit if possible, and i did read up on itthanks for your helpCheers

author: ez24
author_rank: Super Contributor
timestamp: February 25, 2018, 07:06:26 pm
content: Search YouTube for isolation transformer:https://www.youtube.com/results?search_query=isolation+transformer

author: rhb
author_rank: Super Contributor
timestamp: February 25, 2018, 08:22:46 pm
content: What do you call a scientist who had to take remedial classes?An engineer.On a serious note, think back to the EM semester of physics and consider the potential differences of the things you are connecting. You are a lot better off getting in the habit of approaching problems from first principle than relying on some rule of thumb that might not apply in a particular case.Isolation transformers are for handling cases where a circuit ground is referenced to the mains neutral lead. AC/DC radios, TVs and guitar amplifiers are the notorious cases. They are NOT a substitute for thinking about what you're doing. There was a thread a while back started by someone who had blown up their Hantek scope by connecting it to 220 V mains without realizing it. Someone posted a surveillance camera video of 4 men getting killed by pushing a metal scaffold into contact with an overhead power line to the thread. They all died because none of them looked up.One of the big advantages of "hobby" work is you can stop if you are tired or uncertain.