Yet another newbie looking for lab advice - Page 1
Forum section: electronics / beginners

author: Ranayna
author_rank: Super Contributor
timestamp: January 16, 2017, 04:04:13 pm
content: Hi everyoneHere is yet another newbie looking for advice how to setup his lab.I have read quite a lot of threads here regarding that topic and also have watched a few videos. This thread is mainly to confirm (or dispute) the conclusions I have and to ask a few remaining questions.First a few points on what I am doing and what I plan to do. Mainly, at the moment, I am tinkering with Arduinos (Uno, Mega, Nano). I also have a Raspberry Pi that I want to use for some stuff.The project that I have in mind that sparked the need for a more sophisticated lab is that I want to build a Power over Ethernet (PoE) supply for devices like the Arduino or Raspberry.This is what I currently have:A soldering station with analog temp control. I like it, and it has Hakko compatible tips, so that one might still be adequate.A 0-30V 0-5A power supply. I like the usability, but it has virtually no protection circuits. The manual even says it it possible to overheat the unit if used for too log since it is passivly cooled.A cheap 15 euro manual range DMM. I am aware of its safety issues, and usability (and most likely accuracy) makes me want to replace it.I do not have an oscilloscope.What I think I need and want to buy:- Oscilloscope:After reading plenty of threads here regarding this, I think I will not be able to pass the DS1054Z. Hopefully the noise and the input lag will be tolerable, but I do not really want to pay double to avoid those issues. At some point I am very likely to hack the unit.- Power supply:Since I want to build a PoE supply, and PoE runs at nominally 48 volts, I think it would be useful to have a supply that is able to supply that voltage. I have confirmed that the Rigol DP832 can supply up to 60 volts by putting the two 0-30 volts channels in series, please correct me here if I am wrong. Therefore, the DP832 is the unit I want to buy, as it gives me more flexibility than units that go 0-30 volts and is cheaper. As with the oscilloscope, sooner or later this unit will likely be hacked by me.- DMMsI intend to buy two DMMs, and want to get rid of my el cheapo device completely. I am considering Uni-T devices, namely the UT61C and the UT71C. If these are adequate I would buy one of each. I like the datalogging potential for these devices and everything I have listed so far could be bought at the same store (batronix.com)- Hot Air soldering StationThis is the device I am still quite open about. I know that I will very likely need one, but I know virtually nothing about them. My lab is quite space constrained, will I even be able to use one safely? How much clearance is required? How safe it is to use one on a wooden desk with ESD mat?Batronix carries the Atten AT8502D, which would also be able to replace my soldering station, looking at the accessories the iron even uses the same tips as mine. Is this unit adequate? It somehow looks "off" in the pictures.What I do not know if I need it:I know that if I have to ask this question I will likely not need it- Function Generator:I have a JYE Tech FG085 that I bought cheaply as a kit for a soldering practice. I have not really used it yet and don't even know if it works properly. A first use case for an oscilloscopeDo I need a more sophisticated device?- Electronic LoadI imagine having an electronic load would be useful when designing a power supply, but I think I should be able to build something basic myself.What else may I have missed?Greetings,Ranayna

author: rstofer
author_rank: Super Contributor
timestamp: January 16, 2017, 05:43:06 pm
content: It sounds like you are headed in the right direction.Yes, you can add the DP832 outputs together. You will want to turn on "Track" in the lower right of the display. Then just set CH 1 for half the output voltage and you're ready to go.Do be aware of the interconnections between CH2 and CH3. Rigol has a document on how they expect those channels to be used. For op amps, CH1 is the NEGATIVE supply, CH2 is the POSITIVE supply and CH3 is the logic supply.https://www.eevblog.com/forum/testgear/how-to-get-10v-from-dual-power-supply/?action=dlattach;attach=161895As to the FG085, I just built one the other day. Sixty years of messing around with this stuff and I still haven't bought a decent function generator. I do have the Digilent Analog Discovery and that has 2 AWG outputs. I just don't seem to need much in the way of signal generation and, when I do, it is something I can get a uC to generate. In any event, the FG085 is pretty neat. It packs a lot of capability in a very inexpensive unit. The only problems are the limited frequency range and the 256 byte limit for an arbitrary waveform -- something I have NEVER used.I have never had need of an electronic load. I do recall using some automotive lamps to provide a load on something many years ago. If you need one, look around.

author: Cupcakus
author_rank: Contributor
timestamp: January 17, 2017, 07:13:48 am
content: If you're doing any work with SMD components a hot air station is almost a must. I finally picked one up after I bent a bunch of pins trying to drag solder an FPGA and I'll never go back. I don't recommend hot air directly on an ESD mat, it will start to bubble, you can pick up some inexpensive rubber mats for this purpose, I think the Hakko stations even come with them.You'll use it for iron soldering too, as getting flux on your ESD mat is yucky.If you plan on doing repairs, getting one of those cheap ESR component testers on Amazon or EBay is also nice to have in the lab. I never trust the values it gives me but it can spot a dead or failing component really quickly, with no need to break out the scope or DMM probes.

author: Ranayna
author_rank: Super Contributor
timestamp: January 17, 2017, 08:14:26 am
content: The ESR tester is a good idea. I have a couple of devices laying around that might need new caps.The ESD mat I intend to buy claims to be heat resistant:https://www.reichelt.de/ESD-Grounding-Materials/ESD-ARBEITSMATTE/3/index.html?ACTION=3&LA=446&ARTICLE=60391&GROUPID=600&artnr=ESD+ARBEITSMATTE&SEARCH=esd%2BmatteThere are no mentions of a temperature though.

author: macboy
author_rank: Super Contributor
timestamp: January 17, 2017, 03:26:19 pm
content: Your power supply is probably not as bad as you think. You say "it has virtually no protection circuits". The main protection that you need to think about using is its current control knob. Learn to set that appropriately and you will save yourself alotof grief from melted breadboards, smoking wires, and blown components. The fanciest LCD GUI power supply can't save you if you just keep its current control cranked up all the time.The Rigol DS1054Z scope is very good for the price. You can easily get much better scopes by spending more, but not so easily by spending less (not on a new scope anyway).For DMM, get one with good input protection that you can confidently use on higher energy circuits like mains. Never use a cheap meter on the mains. Always have one or two cheaper meters in addition to the good one. There will always be times you need to measure 2 or 3 things at once, and you can use them to cross-check to make sure one hasn't suddenly become faulty. I'd recommend getting the Uni-T UT210E clamp meter as a 2nd or 3rd meter. It is surprisingly convenient to be able to measure current in a wire without needing to break the circuit to insert a traditional ammeter/DMM. It can measure much higher currents than any traditional DMM, and an unexpected surge of current won't blow an expensive fuse. It also is a full DMM with voltage (including true-RMS AC), resistance, capacitance, diode, frequency measurements. It's a bargain at around $40.Get one of thosetransistor/component testers. They can identify and measure capacitors (F and ESR), inductors (H and ESR), resistors, diodes (identify cathode/anode, Vf and sometimes zener reverse breakdown voltage), transistors (identify E/B/C, gain,...), FETs/MOSFETs (identify S/D/G, measure threshold voltage, gate capacitance,...), etc.Veryhandy tool for just $20 or so. And you'll get some more practice soldering, since most are kits. That reminds me that I need to buy another one as I gave mine away to a student.Get good soldering consumables. Kester or Multicore(Loctite) brand solder, Multicore or Chemtronics Chemwick brand desoldering wick, Kester 186 flux pen, etc. Buy this domestically; unfortunately it won't be cheap, but that is exactly the reason that there is so much fake and just plain cheap crap stuff sourced from the far east. I cringe to think about what's really in that cheap Chinese solder

author: Ranayna
author_rank: Super Contributor
timestamp: January 17, 2017, 08:36:30 pm
content: Regarding consumables you are right, the cheap stuff usually sucks.I have Felder 0.75mm 60/40 Solder. For SMD work a bit thick i assume, but for the trough-hole stuff i am doing currently ideal in my experience. I also have wick, also by Felder. I do have a Flux Pen (STANNOL x32-10i) but i have not used it yet. Both Felder and STANNOL are reputable brands as far as i know.That component tester looks neat, already ordered a kitRegarding the DMMs. I am aware that i will at some point need two, that why am considering to get both the UT61C and the UT71C. I know that there are, or were, two different versions of the UT61, but from what i know, Batronix sells the better version. Does the UT71 have the same issue?