Official Electronics Challenge Submission Thread - Page 1
Forum section: electronics / general

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 31, 2016, 01:21:10 pm
content: Submit your proposals here!--------------------------------We need two things:- A list of capable judges- An ever-growing list of goals to buildJudging----------To be a judge, you must have enough instruments to be able to measure the project in question, and the materials and time (and money if necessary) to build and test submissions and prepare a simple report about each. Requirements may vary between challenge, so don't expect to be able to judge everything all the time, or to be able to handle the quantity. Judges should communicate which projects they will test, so that all submissions get tested evenly.Judging basically consists of verifying the submitter's claims. Valid complaints include: "this documentation is crap", "I built it to plan but it doesn't meet spec", and "project burned my house down, please do not attempt". At least two judges must be able to replicate the project, within reasonable variation. (If your project requires selecting a component of particular specs, make it clear how to select and test that component.)Projects, Goals, Ideas-------------------------The idea needs to be:- Able to be completed in a reasonable time frame: a week or two, or several sessions of breadboarding, say- Constructed on breadboard (solderless or otherwise), perfboard, freehand (point to point), copper clad (deadbug), etc.- You can print PCBs for it, but it's entirely at your expense, and you have to supply boards to the judges who will be judging your submission.- Avoids the use of fine pitch and high pin count devices (hard to build, especially without PCBs!), and programmable devices. This is intended to be an analog / discrete digital challenge, not a software challenge. Anyway, the average judge probably doesn't have the toolchain you do, so better not to risk rejection by that reason.- Cool! Cool ideas range from the boring (amplifier, oscillator) to the quirky (voice activated whatsit, sound synth generators) to the awesome (??). Signal generation and filtering is probably a prime candidate.The idea also has to have categories. Anything you find interesting about the subject. Minimal parts count? Highest bandwidth? Lowest distortion? Widest frequency or dynamic range?History---------We did such a challenge on DF years ago, and it generated lots of cool ideas. Here are some examples:http://www.dutchforce.com/~eforum/index.php?showtopic=32914I think the only difference is that I'm insisting on judges here. The aim is to avoid hidden "howd dey do dat?" builds. I admit, this may turn out a logistical nightmare, so we'll see. Coordinating via, say, Google spreadsheet will probably be a good idea.TimProposal thread:https://www.eevblog.com/forum/chat/circuit-design-challengecontest/

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 31, 2016, 01:26:35 pm
content: I can be a judge. (Assuming there's no conflict of interest as also being the organizer, I guess.)Resources:- 350MHz oscilloscope- 1.5GHz spectrum analyzer- 20MHz function generator- Voltmeters- Power supplies up to 2kV- Solderless breadboard and deadbug prototyping capability- Assorted jellybeans: NPN/PNP, MOS, resistors, capacitors, inductors; op-amps, comparators, logic gates- Coil and transformer windingContact: forum messages, email (tiwill@seventransistorlabs.com).Tim

author: MK14
author_rank: Super Contributor
timestamp: March 31, 2016, 01:29:21 pm
content: The goal is to design your own discrete component op-amp. WITHOUT using any integrated circuits or pre-built op-amps etc. ICs with matched transistor arrays and/or matched transistor pairs, are NOT allowed, to make it fair to everyone. (Potentially limited availability and/or huge cost of such parts, make them best avoided).You can use transistors, fets, other discrete semiconductors, and passives.The open loop gain, input impedance, offset voltage, bandwidth, stability, and total parts cost from major suppliers (BOM) contribute to the "best" criterion. Adjustments/calibration trimmers, needing adjustment BEFORE the circuit is properly judged/tested, is fine (since it is NOT being produced as a real IC, which would help match the components, and solve these issues).A set of standard, op-amp configurations, could be used to test/judge the results. Such as x100 gain amp. Integrator. Oscillator. Comparator. Inverting x2 gain amp. Etc.EDIT: A possible criticism of the above (which if so, I fully agree with), is that matched components, may be too important (for good op-amp design), to leave out. I will let others decide the fate of that part of the goal. If it is to be allowed, then a list of allowable matched parts, such as transistor arrays (cheap and readily available ones), could be listed.

author: nctnico
author_rank: Super Contributor
timestamp: March 31, 2016, 02:30:14 pm
content: Maybe it would be better to have the contestants send a prototype to a judge.@MK14: IMHO building a reasonably good opamp without matched transistors is not something which results in something with practical use.

author: MK14
author_rank: Super Contributor
timestamp: March 31, 2016, 02:35:16 pm
content: Quote from: nctnico on March 31, 2016, 02:30:14 pmIt wasn't meant to have a practical use (since op-amp ICs are so cheap, good and plentiful). It was meant to be a good/fun challenge.But I agree that unmatched components, may be completely unfair/unreasonable. Allowing matched (e.g. transistors), is fine by me. Whatever everyone/judges want.I was just worried that they may not be available enough, round the world and/or standardized enough, as they are not so common (in my experience). But (IC packaged) transistor arrays are common, readily available, and fairly matched.

author: MK14
author_rank: Super Contributor
timestamp: March 31, 2016, 02:37:28 pm
content: GOAL:Fastest possible, general purpose, mosfet driver. Fastest wins.Can only use discrete components, such as transistors, small mosfets, passives, etc.MCU (controlling) logic signal, '1' = 3.3V, '0' = 0V, via a series 1K resistor (as not all MCUs can give out that much current).12V supply voltage.Time (start = when logic level is finished transitioning to within 90% of final logic level) to reach >=90% of final on current in mosfets output path/load + Time to reach <= 10% of final off current in mosfet = Result.Smallest total WINS!