Does a combo PSU/function generator exist? - Page 1
Forum section: electronics / testgear

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 12:08:08 am
content: Hi guys!Looking for something that might not exist. LOL!I currently use a DC power supply and a separate function generator (simple one that just adjusts duty cycle) to test cooling fans.I would like to have an all-in-one solution.Essentially, something that looks like a bench power supply, with the current and voltage knobs and displays, but then an additional knob for duty cycle with a display showing the percentage.Does such a beast exist?Working in a cubicle and am just trying to clear up some of the clutter and create better portability.

author: tautech
author_rank: Super Contributor
timestamp: March 09, 2021, 12:28:18 am
content: Welcome to the forum.Most AWG's can provide a variable DC output at modest current however they don't offer CC to my knowledge.

author: mawyatt
author_rank: Super Contributor
timestamp: March 09, 2021, 01:01:57 am
content: I'm not aware of one of these, but you can create the waveform with just about any AWG and a high current buffer amp. If you want to keep the cost down, the Juntek DPA-1698 provides a dual amp with 40VPP and 1A (not simultaneously) maximum capability limited to 10W max per channel and a 100KHz BW. Of course you can always build a DIY buffer amp for any of the popular AWGs.Best,

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 01:21:30 am
content: Quote from: mawyatt on March 09, 2021, 01:01:57 amYeah. That's actually where I'm at today. I'm not without a solution. Just was hoping for an "all in one solution".

author: tautech
author_rank: Super Contributor
timestamp: March 09, 2021, 01:36:52 am
content: How much voltage and current do you want/need, you haven't said.

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 01:40:40 am
content: Quote from: tautech on March 09, 2021, 01:36:52 amOh weird.... I actually did type that out, but it's nowhere to be found.Still trying to get used to this forum format.My fans are usually 12V, 1/2 amp at the most.

author: tautech
author_rank: Super Contributor
timestamp: March 09, 2021, 01:46:33 am
content: Hmmm, a wallwart might be your simplest solution as FG's/AWG's mostly max out at 200mA.See if you can find an old linear one so to not have a SMPS close to the bench spewing RFI.

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 01:50:46 am
content: Quote from: tautech on March 09, 2021, 01:46:33 amHa ha.. Yeah. But I like having the variable voltage output. If I can reduce the fan's overall curve by reducing the voltage and not just the duty cycle, I can design the fan controller to run at a lower voltage.Looks like I'm stuck with my two piece kit.

author: james_s
author_rank: Super Contributor
timestamp: March 09, 2021, 02:32:48 am
content: Seems like a function generator is overkill for this. It's quite a niche instrument, maybe build one yourself? You could start with an inexpensive bench PSU and add the function generator if you want, or just use something like the classic LM317 followed by a PWM stage and put it all in a little box powered by a wall wart.

author: yo0
author_rank: Regular Contributor
timestamp: March 09, 2021, 02:50:04 am
content: Something like that? I think you can still find those used at the bay. I know those exist for English and Spanish speaking usershttps://articulo.mercadolibre.com.mx/MLM-677282512-multimetro-generador-de-funciones-y-fuente-de-alimentacion-_JMBest regards.Pio

author: David Aurora
author_rank: Frequent Contributor
timestamp: March 09, 2021, 02:58:45 am
content: Look into the Tektronix 500/5000 series modular stuff. I picked up a 6 bay mainframe with a couple plugins years ago just because it was a great deal, then loved it so much it became my most used equipment (and I've bought a handful more plugins since). You could easily have a power supply and function generator together in a mainframe, and even extra stuff like a scope/frequency counter/etc to observe details all in one box.

author: Electro Fan
author_rank: Super Contributor
timestamp: March 09, 2021, 04:30:36 am
content: https://en.wikipedia.org/wiki/Source_measure_unithttps://www.analog.com/en/analog-dialogue/studentzone/studentzone-december-2017.html#https://www.tek.com/document/brochure/source-measure-units-save-time-space-and-money-and-make-multiple-measurements

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 04:32:00 am
content: Quote from: Electro Fan on March 09, 2021, 04:30:36 amIs this spam?

author: Electro Fan
author_rank: Super Contributor
timestamp: March 09, 2021, 04:33:45 am
content: Quote from: jonnyGURU on March 09, 2021, 04:32:00 amWhy would it be spam?It answers the question, I think.https://download.tek.com/document/1KW-61419-0_SourceMeasureUnit_SMU_Save-Time-Space-Money_070918.pdf

author: Electro Fan
author_rank: Super Contributor
timestamp: March 09, 2021, 04:35:40 am
content: PS, nice to bite the new hand that feeds you.

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 04:40:51 am
content: Quote from: Electro Fan on March 09, 2021, 04:35:40 amSorry. Thought it might have been one of those bot posts since there were links with no reply or context.Like I said, I'm not without the proper equipment. I can provide power, duty cycle and measure. I just want to do it all in one device (a power supply that allows adjustment of duty cycle). I didn't see in any of the links where that addressed those needs.

author: tautech
author_rank: Super Contributor
timestamp: March 09, 2021, 04:45:39 am
content: What sort of signals do you require from a FG ?

author: Electro Fan
author_rank: Super Contributor
timestamp: March 09, 2021, 04:46:22 am
content: I think SMU is a search term that might help you find some alternatives for what your are looking for, or at least get you in the vicinity.

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 04:49:26 am
content: Quote from: tautech on March 09, 2021, 04:45:39 amI provide power and PWM signal to a fan motor. I adjust the voltage and duty cycle to change the fan's RPM. That's really it.

author: tautech
author_rank: Super Contributor
timestamp: March 09, 2021, 04:52:25 am
content: Quote from: jonnyGURU on March 09, 2021, 04:49:26 amFor other than the fan ?

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 04:53:43 am
content: Quote from: tautech on March 09, 2021, 04:52:25 amThe fan speed is determined by voltage and duty cycle. I need to adjust and monitor both.

author: tautech
author_rank: Super Contributor
timestamp: March 09, 2021, 05:00:00 am
content: Quote from: jonnyGURU on March 09, 2021, 04:53:43 amOK it might be outside the capability of a programmable PSU....just a thought a 3ch PSU might give you options for the supply and the DC if it wasn't too fast.

author: Electro Fan
author_rank: Super Contributor
timestamp: March 09, 2021, 05:36:29 am
content: So this might be similar to what you have?https://www.amazon.com/6-30V-CONTROLLER-DIGITAL-DISPLAY-SWITCH/dp/B016FHHGSUSo you would ideally have this in a lower power version / the power supply and maybe 2 more meters (for current and voltage) all in one box?

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 05:39:08 am
content: Quote from: Electro Fan on March 09, 2021, 05:36:29 amThat's a pretty cheap version (mine's all integrated into a "box") but that's the gist of it.So yeah.. add that to a power supply (fully integrated) and I'm good to go.

author: Keysight DanielBogdanoff
author_rank: Unknown
timestamp: March 09, 2021, 05:46:34 am
content: It's not cheap, but something like a "power analyzer" might fit the bill.https://www.keysight.com/en/pc-1113932/dc-power-analyzer?cc=US&lc=engIt's basically a modular power supply, but you get a scope and some other goodies with it.

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 05:52:02 am
content: Quote from: Keysight DanielBogdanoff on March 09, 2021, 05:46:34 amHa ha! Thanks! Definitely cool kit, but totally overkill.

author: tautech
author_rank: Super Contributor
timestamp: March 09, 2021, 06:10:31 am
content: Get a simpler fan and just vary its voltage ?

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 06:21:07 am
content: Quote from: tautech on March 09, 2021, 06:10:31 amNo no no... I have this set up for testing multiple fans during EVT. We have bigger equipment for measuring CFM and mmAq once the fan is tooled. But in early EVT we're trying to design the fan curve on an MCU fan controller by defining the fan motor's behavior given different voltages and PWM. We don't just use variable DC because it doesn't allow for as much of a granular curve as PWM.

author: Electro Fan
author_rank: Super Contributor
timestamp: March 09, 2021, 06:21:43 am
content: Quote from: jonnyGURU on March 09, 2021, 05:39:08 amMaybe you have invented a new appliance category: standalone powered fan controller or fan management unit or super PWM fan power supply or whatever is descriptive with a good acronym

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 06:27:14 am
content: Quote from: Electro Fan on March 09, 2021, 06:21:43 amI'll see if one of my China ODM's think it's something they want to put on the market.

author: Electro Fan
author_rank: Super Contributor
timestamp: March 09, 2021, 06:45:18 am
content: Quote from: jonnyGURU on March 09, 2021, 06:27:14 amThat’s probably the route.Seriously, there might be small niche for one that is geared toward design and manufacturing use that would be somewhat modular and maybe modestly expensive, and maybe another version that is cost reduced for a bigger market: game PC enthusiasts who want something more versatile and informative than, for example, Corsair’s fan management software.On another side note: if you search in this forum you will see people complaining about fan noise to the point that it becomes part of the decision-making criteria for test equipment products that sell for ~$400 and up; maybe the test equipment industry needs some version of your invention.

author: tautech
author_rank: Super Contributor
timestamp: March 09, 2021, 07:16:35 am
content: Quote from: tautech on March 09, 2021, 05:00:00 amAs more info comes forward I'm rethinking this.Have a look at P3:https://siglentna.com/wp-content/uploads/2020/10/SPD3303X_DataSheet.pdfAlso in the manual it comes with is the list of remote programming commands that might be worth a squiz at:https://siglentna.com/download/2512/A couple of threads showing these PSU's used outside what you would expect:https://www.eevblog.com/forum/testgear/this-graph-brings-tears-to-my-eye/https://www.eevblog.com/forum/testgear/battery-charging-using-a-siglent-sds1104x-and-spd3303x/

author: nfmax
author_rank: Super Contributor
timestamp: March 09, 2021, 08:18:30 am
content: It sounds like a Keysight U3606B would do all you want in one box, provided you don’t mind a fairly low PWM frequency - I think 4.8kHz is the limit. You also get a 5.5 digit multimeter as well. I have the older A version, but it doesn’t get a lot of use - the fan is too loud!

author: james_s
author_rank: Super Contributor
timestamp: March 09, 2021, 08:56:29 am
content: How many fans does one need to be testing before it makes sense to spend hundreds or even thousands of dollars on specialized test gear? Just build something, I would just make a PWM box that plugs into a standard bench PSU but I guess if you're testing a LOT of fans it might make sense to build a custom instrument. This seems like a job for a 8 pin microcontroller and a mosfet, or build a PWM circuit using a ramp generator and comparator, just a few dollars worth of parts, and power it with a bench supply.

author: threephase
author_rank: Regular Contributor
timestamp: March 09, 2021, 09:42:55 am
content: I guess it depends how much you are willing to spend, when I have finished building up my workshop, I am seriously thinking of a Elneos 5 combination unit from Erfi.In Europe they are available from Meilhaus in Germany, not sure if there is a USA based supplier.https://www.meilhaus.de/cgi-bin/cosmoshop/lshop.cgi?ls=en&action=suche&fresh=1&suche_in_rubrik=&suchbegriff=elneos+5

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 05:29:04 pm
content: Quote from: threephase on March 09, 2021, 09:42:55 amAt least you found something that would work for me!https://www.meilhaus.de/en/elneos-five-power-32a-32a.htmIf it didn't have the touchscreen, it probably wouldn't be so expensive!Quote from: james_s on March 09, 2021, 08:56:29 amA lot?https://www.tweaktown.com/news/26799/corsair_takes_fan_testing_seriously/index.htmlQuote from: james_s on March 09, 2021, 08:56:29 amLike I said, I'm not without the tools already. I just want an all in one solution. Something more compact and cleaner. That's all. It's a want. Not a need.

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 05:36:54 pm
content: Quote from: nfmax on March 09, 2021, 08:18:30 amI can't seem to find in the specification where you can adjust the duty cycle of the output, though. I need something that can adjust the pulse width from 10% to 100%.Also seems to cost six times more than my current set up. LOL!Quote from: nfmax on March 09, 2021, 08:18:30 amWhich, for me, would defeat the purpose. The reason I'm not using equipment in the lab is because the lab is too damn loud! I need it to be portable because we move it from office to office, cubicle to cubicle listening for noises that are 15KHz and up from the motor! We had to fight with one manufacturer for six months because none of their old guys in R&D could hear frequencies that high so they refused to make improvements (it only took using a different driver IC)!!!

author: Noy
author_rank: Frequent Contributor
timestamp: March 09, 2021, 06:13:21 pm
content: It exists but is not cheap.Check Toellner TOE 8800 Series:https://www.toellner.de/netzgeraete?pf=284&pi=286I got an older version 8704 it is not as fast as the new ones in programming mode but you can control it with an external AWG at the voltage external inputs but i am not sure how fast this could be. TOE 8800 is definetly fast er..

author: 5370H55V
author_rank: Contributor
timestamp: March 09, 2021, 07:15:23 pm
content: Off topic, but are youthejonnyguru?

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 07:22:31 pm
content: Quote from: 5370H55V on March 09, 2021, 07:15:23 pmI'm afraid so.

author: 5370H55V
author_rank: Contributor
timestamp: March 09, 2021, 07:49:26 pm
content: I thought you might be after that corsair link.Just wanted to say thank you for your PSU reviews! They really helped me build my first PC many years ago, but I didn't really appreciate how detailed they were until after I took some power electronics courses as an EE.

author: jonnyGURU
author_rank: Contributor
timestamp: March 09, 2021, 07:55:35 pm
content: Quote from: 5370H55V on March 09, 2021, 07:49:26 pmThanks.TBH, normally I would have posted this question on the jonnyguru.com forums, but since Tazz fell off the face of the Earth and took the website with him, I needed to find "a new home" for my techie questions.

author: Electro Fan
author_rank: Super Contributor
timestamp: March 09, 2021, 11:56:48 pm
content: Quote from: jonnyGURU on March 09, 2021, 07:22:31 pmKind of off topic....When I mentioned your idea/requirement/project sounded like something that might be a step up from Corsair's fan management software that wasn't a knock on the Corsair software, and I definitely didn't realize your position at Corsair - although maybe I should have. fwiw, I think Corsair's software does a nice job.My thought was just that there might be another level of analysis/tool that some PC builders would like - something that would help enthusiasts more readily determine/compute the air pressure (positive/neutral/negative) and more precisely characterize the airflow so they could in turn more precisely specify/buy and configure/operate their case and fans (in conjunction with the power supply and the rest of the computer). In the end, lots of buyers for various products including computers and test equipment might like to optimize across airflow, temp, power, and sound (or lack thereof.) So the monitor and control you want as a designer/manufacturer might be be a superset of what some end users would like.In any event, sorry for being defensive about spamand I'm happy threephase found you a potential solution. The elneos five looks like something that might get some attention from the Keithley SMU department.I hope you hang out here and the other EEVblog forums. This Test Equipment forum is an excellent forum but you might also find the General Computing forum and some of the other EEVblog forums to be of interest. I'm sure the General Computing folks (and all EEVers) will be very happy to hear from you.

author: jonnyGURU
author_rank: Contributor
timestamp: March 10, 2021, 12:06:21 am
content: Quote from: Electro Fan on March 09, 2021, 11:56:48 pmIt's all good. I didn't think anything of it.