Fluke PM2813 Programmable Power Supply - help me get started - Page 1
Forum section: electronics / testgear

author: mapleLC
author_rank: Frequent Contributor
timestamp: April 01, 2022, 11:23:42 am
content: Fluke PM2813Programmable Power SupplyCan someone please help me get started?What situations do I need a programmable power supply for?Why does this unit only do 8v max? But plenty of current and power.How do these outputs interact with each other? Can they be joined, etc?Any other help?8V-15A-120W Output module specification Linear Power Supplies PM2831, and PM2832Ranges Output Voltage range: 0 to 8VOutput Current range: -15 to + 15AInput / Output Power: 120WProgrammingResolution(12 bit)Voltage: 2 mVCurrent: 3.75 mAOVP: 2.5 mV

author: mapleLC
author_rank: Frequent Contributor
timestamp: April 01, 2022, 11:42:37 am
content: For context, a very close unit was featured in this video.

author: HKJ
author_rank: Super Contributor
timestamp: April 01, 2022, 12:18:26 pm
content: Quote from: mapleLC on April 01, 2022, 11:23:42 amGenerally you use it for automated testing, but that often requires more computer connected equipment (Like a electronic load and maybe some DMM's).You can also be used to load preconfigured settings into it,For a computer interface check AR488, it is a Arduino based GPIB interface.For software you can use:https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/It do not support the PM2813 at the current time, but it can be added to it fairly easy with a ascii definition file.

author: mapleLC
author_rank: Frequent Contributor
timestamp: April 01, 2022, 12:41:50 pm
content: Many thanks. Will this machine interface with modern operating systems then? If so, it does open up possibilities.Is there a world out there of automation for such things which are interchangable like a cad file would be?Any thoughts as to the limited voltage?

author: HKJ
author_rank: Super Contributor
timestamp: April 01, 2022, 01:47:21 pm
content: Quote from: mapleLC on April 01, 2022, 12:41:50 pmIt is up to the GPIB interface, the AR488 interface works nearly everywhere.Quote from: mapleLC on April 01, 2022, 12:41:50 pmNot really, each device has its own language, often it is SCPI based.SCPI is a general way on how to make commands, but the actual commands vary by brand and device.There are different types of software, usually software from a specific brand is limited to only work with devices from that brand. Then there are more general software packages TestController is one of them.There is a fairly standard interface system, that can be installed on a Windows system. It will map all devices to a common interface architecture, this do not have anything with the actual commands to do, but folds socket, GPIB and serial into a single communication interface. TestController do not use this interface, but uses the socket, GPIB, serial ports directly and works on Windows, Linux and Mac.Quote from: mapleLC on April 01, 2022, 12:41:50 pmI wonder about that, I found a datasheet for the PM2813 and it says 30V or/and 60V depending on model.Back in time when many 100 TTL chips was used in a device, a high current 8V supply would probably be very useful in a test setup.

author: mapleLC
author_rank: Frequent Contributor
timestamp: April 01, 2022, 03:36:34 pm
content: Well that makes sense about the 8v, but sheesh, I couldnt have cost that more to make it full featured.In the real world application, are these almost always programmed or used with the buttons on the unit?

author: HKJ
author_rank: Super Contributor
timestamp: April 01, 2022, 03:50:48 pm
content: Quote from: mapleLC on April 01, 2022, 03:36:34 pmDepends on what the real world application is:A lab where you work with one-off devices it will be the front panel.If you often test/repair the same device the remote control is very practical to restore a specific configuration.Automatic test has to be with remote control.Devices with outputs on the back are usually designed for setup in racks for automatic testing.In a hobby lab you can use automatic testing to do a voltage and/or load sweep on a device (Say a boost or buck converter), letting the computer do a couple of hundred test points is much easier that doing 10 or 20 manual test points (TestController is designed to do that kind of stuff and a lot more).

author: mapleLC
author_rank: Frequent Contributor
timestamp: April 01, 2022, 03:57:36 pm
content: Ah. I see. You must program it with software, the front face wont.I hobby mainly with audio gear, so I am trying to understand how I can utilize this. I sense the need for automation is minimal, but it's a hefty solid machine.I was researching this a bit, is it true you can couple all the outputs together to increase the voltage output?

author: HKJ
author_rank: Super Contributor
timestamp: April 01, 2022, 04:06:27 pm
content: Quote from: mapleLC on April 01, 2022, 03:57:36 pmFor automatic testing you also want to record the results and compare them to some reference values.Quote from: mapleLC on April 01, 2022, 03:57:36 pmIf you want a curve over supply voltage vs. performance of a device it can be nice.For audio I would be more interested in a computer controlled generator and a computer controlled voltmeter with a wide bandwidth, then I can do automatic frequency curves and with the power supply also include changing voltage into the test.Quote from: mapleLC on April 01, 2022, 03:57:36 pmFor most power supplies this is possible and a fast check in the manual for PM2813 says that the outputs are isolated, i.e. then can be connection/used in series or parallel.

author: HKJ
author_rank: Super Contributor
timestamp: April 01, 2022, 04:39:28 pm
content: I do not work much with audio equipment, but I used TestController to check the frequency response of some DMM's:https://lygte-info.dk/info/DMMFrequencyResponse%20UK.html

author: J-R
author_rank: Super Contributor
timestamp: April 01, 2022, 04:59:38 pm
content: Quick comment, I think the limited voltage range comes from at least two main factors:1) The design of the supply would need to support the rated amperage at ALL voltages, so 0-8V at 10A is 80W of power, while 0-15V at 10A is 150W. That means a lot more hardware to support the extra power. So the designers are picking their battle here to guess what is good for this particular model and customer base. It probably is designed for 5V work?2) The programming granularity of the output is typically limited to a set number of bits. If you have 1024 set points between 0-8V you could set the voltage to within a value of about 0.008V. If you had the same 1024 set points between 0-20V, you could only set it to within 0.02V.

author: mapleLC
author_rank: Frequent Contributor
timestamp: April 01, 2022, 05:40:40 pm
content: Quote from: HKJ on April 01, 2022, 04:06:27 pmThat helps at least with a wider array of votages if I can join them.Regarding the supply voltage vs performance, I can see that with tube gear, but you are right, the use is likely limited for me.Uses for it will eventually pop up, the high wattage rating will prove useful somehow. For now, its a good quality power supply

author: HKJ
author_rank: Super Contributor
timestamp: April 01, 2022, 06:19:32 pm
content: Quote from: mapleLC on April 01, 2022, 05:40:40 pmIt is a bit large for my bench and the power rating is not that high.My largest power supply is 1200 Watt, it is the same width, but higher (60V or 50A: QPX1200SP).My other supplies (That I use) are half the width or slimmer and below 200 watt.Power supplies depends on what you do, for audio I would expect you mostly want symmetric power supplies below 20V with a couple of 100mA output and then a high power supply for output stages. You might also want a 3.3V/5V supply for digital audio.

author: mapleLC
author_rank: Frequent Contributor
timestamp: April 02, 2022, 12:16:07 pm
content: Quote from: HKJ on April 01, 2022, 06:19:32 pmI am glad I started this thread, its been very informative, largely to your help, thanks.Thats a beautiful piece of kit. I am glad you mentioned it as it gives me a reference point.I think I have a good supply, it will be useful, but when I start banging on its limits I should view it as a sign of growth and then invest in a better unit.It crossed my mind that perhaps I can modify the unit I have to output more, knowing manufacturing, they didnt reinvent the wheel inside this thing, its likely a few components would do it. Anyway, thats a rabbit hole I dont need right now

author: HKJ
author_rank: Super Contributor
timestamp: April 02, 2022, 01:03:27 pm
content: Quote from: mapleLC on April 02, 2022, 12:16:07 pmThe other supplies I uses are:TTi QL355P - 1 channel 0-35V 3ARhode & Schwarz HMC8043 - 3 channel 0-32V 30W each channelKeithley 2280-32-6 - 1 channel precision supply 0-32V 6A, one this supply I often use 4 terminal connection for best precision.On the HMC8043 I can link the channels for a total of 90VThey do all have computer connection and I often uses it.

author: mapleLC
author_rank: Frequent Contributor
timestamp: April 03, 2022, 07:40:32 am
content: Negative voltage, is this a specific capability with these supplies?Is this something a supply specifically has to support or do they all do this and some label their equipment differently?I came across this article, which is topical.https://forum.digikey.com/t/get-a-positive-and-negative-voltage-output-from-power-supply/10593

author: HKJ
author_rank: Super Contributor
timestamp: April 03, 2022, 08:02:57 am
content: Quote from: mapleLC on April 03, 2022, 07:40:32 amBecause power supplies usually have floating outputs, you can link them up to get negative voltage. I.e. put two 5V supplies in series and call the point where you link them in series 0V, then you have -5V and +5V.This works best with multichannel supplies, because you can turn the outputs on simultaneous and overload protection may be linked, i.e. both + and - turns off in a overload condition (Not all supplies can do that, HMC8043 can).TestController do directly support setting up +/- voltages on HMC8043:

author: mapleLC
author_rank: Frequent Contributor
timestamp: April 03, 2022, 11:58:47 am
content: I will research the test cafe tools with a bit of time, thank you.I watched a vid on the process after your post, I can see how it works now. It looks like some supplies are offering this as a feature now.