Looking to equip a classroom - Page 1
Forum section: electronics / testgear

author: fusia
author_rank: Newbie
timestamp: June 13, 2017, 03:21:50 am
content: Hey everyone, I'm an electronics teacher and I have a opportunity for one if not two grants worth $5500 each. Pretty sweet, I know. My goal for one of them is to get some test equipment. The other would one for classroom supplies, project stuff, etc. I'm looking for advice on what to put in my grant proposal. A few things to note: 1) this is a high school classroom, not a university; 2) I would prefer 10 sets, with a minimum of 6; 3) I am not an electrical engineer and haven't really worked in the electronics field. With that last part being said, I have a Bachelors in Physics and an Associates in Biomedical Equipment Technology. I was supposed to have learned about electronics while getting my Associates, but the professor was HORRIBLE so I've been teaching myself over the past couple years and love learning and teaching electronics! This however means that my technical prowess is limited.With that out of the way, this is what I have. I have a cart set up in Aliexpress that has this:15 x Fluke 17b+ for $106 (has all the features I would like, specifically uA measurements; plus its a solid, safe Fluke)10 x FeelTech FY3206S 6MHz Function Gen. for $65 (basic with duty cycle control and sweep)10 x Hantek DSO5102P 100MHz scope for $216 (basic scope, I don't really need 200+ MHz range)1 x Hantek DSO8102E $585 (mostly for the spectrum analyzer, would prefer low freq range (kHz) to pair with function generator - not necessarily for RF)I have qualms with using Aliexpress because I've never used it before and I don't want to get screwed over.I'm looking for economical not top of the line here. I know what I have isn't the best, but it may just work for what I need: classroom experiments and exploration. I would like a logic analyzer too if possible (maybe just 6-8 channels built into something.) My alternatives are to get better stuff Insteck GFG8215A generator (~$150) and Rigol DS1052E scope (~$330), and put the multimeters in the other grant. OR just get some decent laptops and buy cheaper computer-based scopes. And FYI, the school has most of this stuff, but what I get from the grant is mine; if I change schools, this stuff comes with me.Any advice?? Tear the order apart, fellas!

author: colorado.rob
author_rank: Frequent Contributor
timestamp: June 13, 2017, 03:32:04 am
content: I didn't see any power supplies in that list. Do you need them?

author: xrunner
author_rank: Super Contributor
timestamp: June 13, 2017, 03:56:46 am
content: BNC - BNC cables so you can hook things together for simple signal examination/teaching.

author: Fungus
author_rank: Super Contributor
timestamp: June 13, 2017, 05:12:59 am
content: Quote from: colorado.rob on June 13, 2017, 03:32:04 amFirst thing I thought of as well. Should be top of the list.What about soldering irons/breadboards/cables-with-crocodile-clips? That's very important.Multimeters: Essential, 17B is good.I don't think they need individual function generators. Maybe one for the teacher to pair with his spectrum analyzer if you're going to teach signal theory. Get them to install tone generator apps on their 'phones instead, that way all you need is a headphone cable. Buy power supplies with the savings.Hantek 'scopes are bad, mmmkay:But ... 'scopes is a tough one. Ten of anything worth having is going to be around $4000. If that's all the budget you have then get the Hantek and stick to minimal functions. I wouldn't wish one on anybody for real work but they're enough to teach kids how to connect probes and set the horizontal and vertical scale on a 'scope - which is all good. The important thing is to teach, not to have amazing equipment!I'd stay away from USB 'scopes. You'll spend too many hours installing drivers on their laptops - big distraction!

author: nctnico
author_rank: Super Contributor
timestamp: June 13, 2017, 06:33:56 am
content: Give GW Instek or Keysight a call since they seem to outfit quite a lot classrooms. At quantities you'll likely get a discount and on top of that manufacturers like to have their equipment in classrooms. I'd avoid brands like Hantek, Owon, Siglent and Rigol due to bugs in the firmware which could lead to confused students and thus time wasted (especially if you are a not well versed in using an oscilloscope yourself). There is nothing more frustrating for students than being distracted by equipment problems.I second the suggestion to also get some power supplies, BNC cables and 4mm banana leads. The Feeltech generator is OK but you'll need to get the version with a grounded mains inlet otherwise it is very easy to damage a circuit due to the leakage current from the mains. You could look at the EDUX1002G from Keysight which has a built-in generator but don't look at distributors for pricing. Call Keysight and tell them your wishes & budget.

author: Fungus
author_rank: Super Contributor
timestamp: June 13, 2017, 07:12:43 am
content: Quote from: nctnico on June 13, 2017, 06:33:56 amI don't want this thread to degenerate into yet another holy war over 'scope brands, but having stood in a classroom I'll say this:There's alotof value in teaching kids thatreal-world equipment is fallible, that they shouldn't trust it no matter what the badge on the front says. These 'scopes are only going to be used for a few hours and not for important work so let Hantek be a horrible warning! Find a bug? Well done! If you can prevent a student from buying one with their own money that's priceless.So long as they can display a waveform, measure a frequency, etc. then they're good enough for "learn to use an oscilloscope"* class. Ignore the EEVBLOG snobs. Kids get it, they know stuff isn't perfect.(*) I'm making the massive assumption that that's what they're for.nb. It might be worth buying justonefirst, to check it out.

author: abraxa
author_rank: Frequent Contributor
timestamp: June 13, 2017, 07:40:04 am
content: First off I'd like to thank you for trying to get students interested in EE. Without teachers like you, a lot of students will never be realizing what an interesting field this is - even if the majority of the students may choose to not care about it. But that's okay, it's not for everyone.That said, I'm missing a list of your actual requirements - as in, a list of experiements you want to perform. You mention uA range, for example, but what for? Without knowing what you want to do it's a little tricky to suggest you the right gear.One thing I found a little odd is that you say the school already has most of the stuff, yet you want to buy it for yourself to take with you. Is it common for teachers to change schools in the US? I mean... is it an important aspect for you to be able to take everything with you? Unless you intend to change schools soon (or expect to be forced to), I'd look at what the school has. Maybe they have things that you then don't need to buy, leaving more money for the other items. Then, in the future, maybe another grant can complete your set?Also, is theft an issue? Do you have a safe place to store those items or would you have to buy a lockable cabinet from the grant, too?As for the logic analyzer, I'll just point out the obvious choice: get an 8-channel one for $10 or less (https://www.amazon.com/dp/B07253BSQJ/for example, am not affiliated with them) and use sigrok. Yes, those devices can be used with a commercial software that's mentioned in the article description but that's illegal to do, so please don't. Using sigrok would allow you to give them a gentle introduction to open source, tooEdit: Tektronix and Keysight have both created study material (and in the case of Keysight, even a scope series) for the single purpose of entering the education market. I wouldn't be surprised if they'd be willing to jump through hoops just to get a foot in the door. So nctnico's suggestion isn't actually as strange as it may seem.

author: Fungus
author_rank: Super Contributor
timestamp: June 13, 2017, 08:21:57 am
content: Quote from: abraxa on June 13, 2017, 07:40:04 amTrue, but they're aiming at rich schools. You'll need a 60%+ discount on even the base model to get it within budget.(not impossible, but...)

author: nowlan
author_rank: Frequent Contributor
timestamp: June 13, 2017, 08:46:25 am
content: Always contact tek/keysight direct. They will offer discounts to a school. Same with any manufacturer. A class set will make the commission back.My local tafe bought hantek because they were cheap, and disposable i guess. I notice the university has a few Siglents these days.Not sure what high school students are learning these days? Arduion type stuff? or the basics, DC/AC & Opamps?You might look into getting a bunch of analog discoveries instead.

author: nctnico
author_rank: Super Contributor
timestamp: June 13, 2017, 08:53:08 am
content: Quote from: Fungus on June 13, 2017, 07:12:43 amI guess you never went to school. How can you learn if the materials used for teaching are flawed? Imagine learning a language from a book with spelling errors

author: tautech
author_rank: Super Contributor
timestamp: June 13, 2017, 08:59:56 am
content: @fusaHaving supplied learning institutions I can tell you this:edudiscounts will probably apply but you will have to source them via an authorised dealer/distributor. They are generally given at the discretion of the factory sales manager.For better supplier support try to get as much as possible in a single brand.....you and the students will benefit from a familiar UI across the model range you get and better support having bought from one supplier.You have already seen some members have an axe to grind over certain brands, any bugs that there might be in any equipment will unlikely be noticed by you or students and are constantly being fixed inmostbrands.You could PM member Siglent America and get one his crew to put a package together for you:https://www.eevblog.com/forum/profile/?u=97174http://www.siglentamerica.com/how_to_buyfor dealers close to you.

author: Fungus
author_rank: Super Contributor
timestamp: June 13, 2017, 09:19:08 am
content: Quote from: tautech on June 13, 2017, 08:59:56 am100%.Quote from: tautech on June 13, 2017, 08:59:56 amThe new low-end Siglent is better than a Hantek and may fit the budget with an edu discount.Plus you'll have support if one breaks (unlike aliexpress).

author: AndyC_772
author_rank: Super Contributor
timestamp: June 13, 2017, 10:57:07 am
content: Quote from: Fungus on June 13, 2017, 07:12:43 amI'm going to play devil's advocate here and say the exact opposite.If the goal is to learn how electricity behaves, students are going to be faced with plenty of situations in which what they see isn't what they were expecting, or which they can't explain at all. Learning how to use a scope takes time, learning why a scope trace looks how it does under a wide range of circumstances takes even longer, and getting to the point of being able to reliably diagnose when test equipment is simply not doing what it's meant to do takes years of experience.When you're learning a skill, you shouldn't have to also cope with the limitations of bad tools. They're an obstacle to learning.

author: mubes
author_rank: Regular Contributor
timestamp: June 13, 2017, 11:16:17 am
content: Personally I would look at the Keysight 1000 edu stuff rather than sourcing in the far East....if anything goes wrong you stand much more chance of getting it fixed in comparison with an aliexpress dealer....plus they have things like Sig gens built in (==one less set of leads to loose). I would ping Keysight Daniel on this forum to point you in the right direction.Conversely, Aliexpress all the way for components. I've set up a 'Tuck Shop' at work filled up with Aliexpress Jellybean components with a honour pot next to it...the guys who are into hobby electronics just come grab what they want and chuck a couple of coins into the pot, which pays for the next foray. It works really well. Those components are firewalled away from day-job stuff though where traceability, certificates of conformity, RoHS and warranty all become considerably more important.Dave

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: June 13, 2017, 11:22:33 am
content: Yeah go for an educational discount, should be able to get 30% off easily. (For scopes anyway.)Get one of the new keysights 1000 series and I think they have educational stuff built in.You might even be able to spring for one RTB2000?I think a range of equipment is good, as you can compare strengths and weaknesses, UI, functionality.What about the Uni-T meters they have a stack of functionality.

author: Fungus
author_rank: Super Contributor
timestamp: June 13, 2017, 11:28:09 am
content: Quote from: AndyC_772 on June 13, 2017, 10:57:07 amThat's true ofalloscilloscopes.Quote from: AndyC_772 on June 13, 2017, 10:57:07 amI know I'm making a lot of assumptions about the classes here, but ... oscilloscopes are expensive and they really aren't a central part of a basic electronics class. The multimeters (for example) are an order of magnitude more important.The oscilloscope teaching isn't going to be much more than connecting up the oscilloscope, setting the horizontal/vertical scales, measuring a frequency, connecting it to a signal (eg. a mobile phone, a potentiometer), learning where you can't put the ground clip, etc. It seems unlikely that the Hantek (or whatever) can't do that.Whatever you save on oscilloscopes you can spend on basic stuff like power supplies, soldering irons, breadboards, cables, prototype PCBs, packets of LEDs, potentiometers, etc. All of that is more important than the oscilloscopes (IMHO).

author: Fungus
author_rank: Super Contributor
timestamp: June 13, 2017, 11:37:44 am
content: Quote from: mubes on June 13, 2017, 11:16:17 amStarting at $500 each, no memory and a screen smaller than a mobile phone? What am I failing to see?I'd call Siglent first.

author: nctnico
author_rank: Super Contributor
timestamp: June 13, 2017, 11:44:54 am
content: Quote from: Fungus on June 13, 2017, 11:37:44 amA lot. The educational materials and the bode diagram (network analysis) function. It is pretty neat to have students see stuff like phase shifts in RC circuits, amplifier bandwidth, resonator curves, etc without needing fancy equipment or going through tedious routines. IMHO you get a whole lot more from an educational package than just an oscilloscope.

author: Fungus
author_rank: Super Contributor
timestamp: June 13, 2017, 12:06:03 pm
content: Quote from: nctnico on June 13, 2017, 11:44:54 amLet's see if the OP's students are likely to be looking at any of that stuff.

author: alexanderbrevig
author_rank: Frequent Contributor
timestamp: June 13, 2017, 12:42:57 pm
content: My initial response has been perfectly laid out by Fungus. Strive for the best you can get og course, but get enough of something less, instead of less of too much.Even forcing errors (what you see is not what you get) I'd an excellent learning opportunity.

author: fusia
author_rank: Newbie
timestamp: June 14, 2017, 02:56:57 am
content: Thanks everyone for your advice! I will definitely scrap the Aliexpress cart and start contacting reps.I was looking at putting the power supplies in the other grant along with breadboards, components, irons, and everything else. Somehow my predecessor had scopes and multimeters for the class but only 2 power supplies. I've been doing everything off 9V batteries; I'm not proud of that and it really sucks using them, but don't worry supplies are high on the priority list. The BNC cables are also on this grant budget, I just didn't feel like listing them here.As for what kind of experiments I'll be doing. A good multimeter can be used in everything obviously; the scopes will be used in (yes) learning to hook it up, find frequency, etc. but also showing how rectifiers, op amps, and PWMs work. I do like the idea of just finding signals online and saving on the generators, but its tricky to connect the wave to a circuit for testing on filter and resonant circuits. I guess an amp would be a good project for them though. There are three classes (basic electricity, AC & Analog circuits, and Digital circuits) that these fall into and I'm working on beefing everything up and providing some more complex stuff. I do have Arduinos that I've included in the class, but its not central.Quote from: abraxa on June 13, 2017, 07:40:04 amLong story.

author: ebclr
author_rank: Super Contributor
timestamp: June 14, 2017, 03:25:00 am
content: In USA Amazon can be more convenient than aliexpresshttps://www.amazon.com/s/ref=nb_sb_noss_2/146-3763930-7680268?url=search-alias%3Daps&field-keywords=hantekAlso checkhttp://www.saelig.com/

author: theatrus
author_rank: Frequent Contributor
timestamp: June 14, 2017, 06:20:51 am
content: Quote from: 3roomlab on June 14, 2017, 03:12:47 amI was about to jump in and mention this as well. Edu discounts would make this pretty attractive, and I believe it has some curriculum already around it.

author: nctnico
author_rank: Super Contributor
timestamp: June 14, 2017, 06:41:03 am
content: Quote from: theatrus on June 14, 2017, 06:20:51 amThe downside of the Analog Discovery is that it's input ranges are very limited. A regular oscilloscope is able to survive probing mains (especially 115V commonly used in the US) and severe ESD events. IMHO the Analog Discovery is way too frugal for use in a classroom.

author: Fungus
author_rank: Super Contributor
timestamp: June 14, 2017, 06:49:02 am
content: Quote from: nctnico on June 14, 2017, 06:41:03 amIt also has a lot of fiddly cables, delicate connectors and requires drivers/software/laptop to be any use.

author: edgelog
author_rank: Regular Contributor
timestamp: June 14, 2017, 07:48:50 am
content: Quote from: fusia on June 13, 2017, 03:21:50 amI've used Aliexpress a few times, got delivered what I ordered, but had to stop using them since it proved impossible to get decent receipts or invoices. If you buy anything for a company or institution, you need paperwork, and Aliexpress seems to go out of their way to not give you any of that.eBay also has that problem, but to a lesser degree. If you pay through Paypal, you've got at least a description of the order and payment. A real invoice is still hard to get.

author: Aviator X
author_rank: Contributor
timestamp: July 05, 2017, 06:45:19 pm
content: There are three classes (basic electricity, AC & Analog circuits, and Digital circuits) that these fall into and I'm working on beefing everything up and providing some more complex stuff. I do have Arduinos that I've included in the class, but its not central.Quote from: abraxa on June 13, 2017, 07:40:04 amLong story.errm the digilent all in one discovery is worth consideringTwo-channel USB digital oscilloscope (1M?, ±25V, differential, 14-bit, 100MS/s, 30MHz+ bandwidth - with the Analog Discovery BNC Adapter Board)Two-channel arbitrary function generator (±5V, 14-bit, 100MS/s, 12MHz+ bandwidth - with the Analog Discovery BNC Adapter Board)Stereo audio amplifier to drive external headphones or speakers with replicated AWG signals16-channel digital logic analyzer (3.3V CMOS and 1.8V or 5V tolerant, 100MS/s)16-channel pattern generator (3.3V CMOS, 100MS/s)16-channel virtual digital I/O including buttons, switches, and LEDs – perfect for logic training applicationsTwo input/output digital trigger signals for linking multiple instruments (3.3V CMOS)Single channel voltmeter (AC, DC, ±25V)Network analyzer – Bode, Nyquist, Nichols transfer diagrams of a circuit. Range: 1Hz to 10MHzSpectrum Analyzer – power spectrum and spectral measurements (noise floor, SFDR, SNR, THD, etc.)Digital Bus Analyzers (SPI, I²C, UART, Parallel)Two programmable power supplies (0…+5V , 0…-5V). The maximum available output current and power depend on the Analog Discovery 2 powering choice:and its got educator discount i think? no?http://store.digilentinc.com/analog-discovery-2-100msps-usb-oscilloscope-logic-analyzer-and-variable-power-supply/I too am looking to outfit a classroom. Unfortunately it will not be a regular course, but an afterschool program with little to no funding. I will need to start with only the essentials. I am browsing the threads for curriculums and equipment ideas. Thanks for the inspiration.