Goofing around with a Keithley 2461 SourceMeter

this video has been supported by Tektronix hey guys they've sent over one of their no longer brand-new but in comparison to everything else in this corner absolutely futuristic touchscreen SM use in contrast to my high voltage hot rod this is a high current model that can deliver seven Empire continuously and ten Empire in short pulses that's a maximum of one kilowatt pulse energy and a key feature for this beautiful Keithley another obvious one is the completely made over user interface that takes a short boot time but in exchange gives you a number of functions that no other SMU ever had in this video I'm just going to be goofing around with it a little bit to get to know my way around a first practical laser II application is going to be in a separate video for now III two four six one saw Smita let's go first I want to satisfy my morbid curiosity and see what happens when you put a short 1 kilo watt pulse we do a quarter watt metal film resistor there is a special submenu for configuring pulses after entering the parameters and generating the configuration it will perform a brief sanity check to see if what you want is possible luckily it doesn't know that I've connected this flimsy resistor otherwise it would probably shut down and cease to cooperate with me I've asked for a 5 second delay so that I can take cover somewhere oh was that all inductance of the long test lead has kind of thwarted my evil plans this time still almost 600 watt were present briefly and the resistor only got this small puncture where part of it was vaporized oh and we are taking deep breaths to prepare for another such Pollitz how about an old carbon specimen just kidding that was also laughable but with a high-speed data acquisition mode which they call digitizers we can record these short events at 1 million samples per second that is a very useful feature for analyzing the behavior of circuit protection devices like poly fuses which are essentially PTC's that warm up and increase in their resistance or transient voltage suppress which are essentially Zener diodes that sacrifices themselves for the greater good absolutely heroic there are much more interesting diodes out there though not all of them are well suited to demonstrate destructive high power pulses these continuous-wave laser diodes especially deserve a clean ripple free power supply we'll do more with those later with a focus on higher current they didn't equip this SMU with traditional tri-axial connectors but it does have the fantastic one picoampere measurement resolution that goes crazy when you do as little as move around too near a set up there is a screw terminal on the rear with guard pins for applications where a leakage current Mehta's in a low impedance situation there is some misleading thermocouple current that effect is built right into the connectors but in those rare cases where it matters you can probably build a thermally stable test fixture and zero it out in high impedance circuits which are the best kind of circuits anyway everything is fine in really high impedance circuits too but I think here we would need shielding and guarding again because this is supposed to be a 1% 100 Giga resistor these are hermetically sealed low leakage diodes half a Pico ampere according to the data sheet for $20 apiece in single quantities with long test leads in the front panel we are getting over 50 Pico ampere readings just by using the screw terminals and a flappy piece of aluminium tape for shielding things get much better so in conclusion I miss my tri X connectors but for what this thing has been designed it's all good it was not designed for this of course but it can pretend to be a simple old power supply including web-browser remote control up to six-and-a-half digit resolution and bipolar output it's actually even better than bipolar like every good azimu it's a four quadrant device that can both source and sync a high-power meaning it can charge and discharge a wide variety of batteries endcaps that way it can generate data based on which ESR AKA internal resistance state of charge capacity and maybe even h can be calculated there isn't a special user interface prepared for that particular application but you can create a complex flow chart with logic timers source and measure actions digital i/os and everything else right there on the touch screen this one will take a measurement and do nothing if the voltage on that huge cap is already over three volt otherwise it'll enable the source output for one second and jump back to the start afterwards it's a very crude bang-bang controller and a function that the instrument itself does much more effortlessly but wow the possibilities with his flow chart mode are endless well I'm actually not sure about the endlessness but many flow chart languages are turing-complete so you can probably implement doom on your SMU or something look at it work beautiful what's next I wonder if we can integrate current over time to measure charge or control motors with the GPIO pins and automatically characterize oddities like pressure versus lipo voltage the flow chart generator is really cool for setting up a complicated test in situ but it's not all there is an entire software development kit the Keithley test script builder that gives you complete control of your instrument with a lure like language if you've ever programmed an Arduino then you're immediately able to understand and work with the provided examples and this one will single-handedly record an IV sweep on a solar cell and characterize it head to toe dude that is not a solar cell that's an entire ready to roof module consisting of many equal solar cells having all of them working simultaneously makes things pretty difficult for a research great instrument but the high current sauce meter almost reaches the maximum power point in straight-up DC electronic load mode now it would be really interesting to see if with a modified test script and a limited duty cycle we could reach and to go right past to that point maybe even compile a VI plot like this but purely from pulsed data but right now I've got even more interesting things upstairs this dubious package might need some personal protective equipment because knowing where it came from it's probably full of unbearable newspapers and a few scientific artifacts one might almost think that the sender is aware of my appreciation for warning labels and my willingness to recommend his awesome Twitter feed in exchange for these check out giga Packer L on Twitter to find out what these carbon straws are and how he got them personally at CERN I don't think they used them as tent poles or look as an e-cigarette in there anyways back to the matter at hand here are some smaller more interesting solar cells they are actually photo diodes for precision photometry they have a fantastic part number s103 37 and a really Universal spectral response from UV to IR I've put one in that metal box and left only a narrow slit open for some ambient light to leak in even though that's such a crude setup the sensitivity of both of the photodiode and the Keithley under test are clearly enough to detect my movements probably from shadows on that wall I can also just kill the lights and watch how slowly but inevitably the last bit of daylight is fading out it was a fun day and now I know the basics of operating the key 3 2 4 6 1 now I'm feeling ready for a real application how about you

Channel: Marco Reps

Views: 69,310

Rating: 4.9095516 out of 5

Keywords: marco, reps, electronic, engineering, keithley, smu, source, measure, unit, arduino, raspberry, pi, lab, bench, power, supply, review, volt, ampere, picoampere, 2461, meter, measurement, test, equipment, color, lcd, tektronix, quadrant, led, laser, photodiode, reistor, open, digitizer, polyfuse, ptc, fuse, tvs, zener, diode, solar, photovoltaic, current, guard, leakage, impedance, curve, tracer, lxi, triggerflow, flow, chart, script, builder, capacitor, characterize, module, load, v-i-plot, pulse, geiger, muller, counter, tube, cern, straw

Id: Mk9NQ0XbZUE

Length: 11min 20sec (680 seconds)

Published: Mon Nov 18 2019