RoadTest: E36313A Triple Output DC P.S.
Author: luislabmo
Creation date:
Evaluation Type: Power Supplies
Did you receive all parts the manufacturer stated would be included in the package?: True
What other parts do you consider comparable to this product?: I've considered other products in similar category based on information available online but can only provide a comparison point based on my experience as this is the first time I've ever gotten my hands into a Variable Power Supply.
What were the biggest problems encountered?: Critical Bugs: the unit has some bugs, also the user manual. I consider this needs special attention as some bugs freeze the PSU completely in whatever state it is representing risk. Cosmetic damage: there was an area were the paint was rubbed off, it may have been caused by too much friction, a bad paint job, or maybe poor packaging.
Detailed Review:
The https://www.element14.com/community/view-product.jspa?fsku=&nsku=15AC9660&COM=noscriptE36313A is very powerful and brings a lot of good features with a very intuitive user interface, I think it will be great addition to any workbench. If you are a hobbyist like me, an instrument in this price segment may be a little overkill but, will serve you for many years to come as it packs very good specifications and will help you in your projects with ease. I've found few negative aspects but I don't think this will take merit from a good product like this as it performs very well in what its main purposes are: providing 3 outputs with clean and stable power and extra features.
The E36313A came held in place with custom packaging inside a sturdy box, on top of it came a small box with documents and parts. Unfortunatelly there were few scuff marks present in the PSU, the paint was was rubbed off where the scuff marks were, matching exactly the corrugation pattern of the smaller box that came on top, which led me to think that too much friction or a not so good paint job cased the issue?. Well, before I took the PSU out of the box, I noticed that it wasn't inside a plastic bag -and then held in place with the custom packaging- this practice I've seen in many electronic devices I've bought before like Monitors, Computer cases, Soldering stations, etc., maybe this was the real cause of the issue.
| {gallery:width=640,height=360} Unboxing |
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E36313A Unboxing: Big box |
E36313A Unboxing: Paint damage |
E36313A Unboxing: Custom packaging |
E36313A Unboxing: Box with items |
E36313A Unboxing: Extra items |
E36313A Unboxing: Extra Parts |
This PSU provides many great features. I'm going to list some that are advertised which I think are the the best features this unit may bring to you:
It feels great overall!. Unit looks good, construction is rigid and sturdy, rubber buttons look and feel good, the rotary click switches and their rubber knobs are perfect -to my taste every click feels right: soft but accurate... and I tried them A LOT-.
One thing that got me mixed feelings was how every button press felt. I personally dislike long buttons, some times they feel wobbly and imprecise -depending how firm your hand is-, unfortunately, most of the buttons are like this.
| {gallery:width=768,height=432} E36313A |
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E36313A: Idle |
E36313A: Off |
The AC power entry feels wobbly, tested this with other AC power cords, ironically, this may represent an advantage in some situations; this PSU has some software bugs that may freeze it completely and the only option available is to disconnect the mains power -more on that later-. On a serious note, a grounded power switch is highly recommended until a more stable firmware is released.
The fan in this unit is always ON. When the PSU is Off, the fan will be running at a very low speed.
Display
The power supply's front panel features a high contrast 4.3-inch LED color display, a little glossy -not a problem here-, image quality is very sharp, the view angle is just enough for an instrument like this, the layout and the information displayed is on spot, displaying the necessary information for each channel matching the color-coded channels (buttons, output terminals and the paint job). The Multiple Output View displays the actual output voltage and current and the present output voltage and current settings.
Also when needed, a meter view is available which displays more information on a selected channel:
| {gallery:width=480,height=272,autoplay=false} Meter View |
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Meter View Ch1: LCD detailed view of Output 1 |
Meter View Ch2: LCD detailed view of Output 2 |
Meter View Ch3: LCD detailed view of Output 3 |
Can be noted also that when changing a configuration affecting a single channel, the configuration color will match the the channel color-code, also the matching output selection key will light up.
| {gallery:width=480,height=272,autoplay=false} Screen examples |
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Output 1 - Source Settings: Note the Yellow color matching the Output 1 color-code |
Output 2 - LIST Properties: Note the Green color matching the Output 2 color-code |
Output 3 - Output LIST: Note the Blue color matching the Output 3 color-code |
Selects an output to control. The lit key indicates the selected output.
Turns individual outputs On/Off; outputs are On when the key is lit.
The user experience is good overall, simple to operate and intuitive to use in big part thanks the color-coding scheme and the color LCD, making very easy to understand what are you doing and where. In all my tests, I did measurements with other instruments and this is one of the aspects this unit excels; provides precise voltage and current output control and high accuracy readings making the user experience hassle free as there is almost no need for separate measurement instruments.
First thing first, please pay attention to the User's Guide recommendations -I will talk about this in more detail later-.
When turning the E36313AE36313A on, it takes around 6 seconds to be ready to use. For a smart PSU with a micro-controller and a OS that has to manage a USB port, 3-outputs, Network capabilities, a nice presentation of the data, and all the features this unit brings I say 6 seconds is a good startup time. When the unit starts, the FAN speeds up for about a second, this is a common practice I've seen in Servers and some PCs of reputable brand.
A numeric keypad is available to accurately adjust the Voltage or Current settings. Independent Voltage and Current knobs may be used too, which use acceleration to make for higher/lower increments, feature that I personally like and find very useful most of the times, but, a little bit dangerous sometimes: when adjusting the Voltage/Current while an output is ON, if not careful, you may end up going too far, risking the integrity of whatever you have connected to the output. I would have done this feature a little different, by using rotary encoder with switch, this way the knob can be pushed to toggle on-off the acceleration feature and also adding an icon indicating such status.
It is been brought to my intention that with the outputs OFF, the PSU reads some current and voltage values, makes me wonder whether those are offset values or perhaps noise?. Should I account for those values when using the PSU?. I used a multi-meter and I didn't detect any voltage/current in any of the outputs while they are OFF.
One thing I didn't like at all is, when in other menu options, you won't have any idea of what is going on with the outputs (except the On/Off lights), this is ok BUT, if you turn the Voltage/Current knobs you may end up changing the Voltage/Current settings without any feedback as you are not in the meter view -I think this is a little risky-.
When entering any Voltage/Current using the keypad, it allows to input up to 9 digits which I find not very useful as the unit does not handle that much precision and only displays maximum 5 digits (not including decimal separator).
The Data Logger works very well, I think it is one of the best extra features this unit brings as there is almost no need of extra measuring equipment you may select to record Voltage, Current and Power independently for each output. The data logger seems fluid an accurate and allows to visualize in a nice graph what is happening with the outputs. The Data Logger also has the option to export the data in a very common format (CSV). On the downside the minimum sample period allowed for the data logger is just 200ms 
also, a USB flash drive is required to use the data logger.
When the Data Logger is operating, if you decide to switch to another screen, a notification at the top of the screen will indicate that the data logger is actively recording.
Adding a time-stamp to the log filenames is not the default option, which I think it should be. You should activate this option every time you plan to use the data logger -and yes, every time you turn off the PSU the option doesn't get saved-. Ironically, screenshot filenames always include the time-stamp. If you prefer to save screenshots in PNG over BMP format <default>, this is another option that doesn't get saved once the instrument is turned Off 
.
I think everybody tests their new shiny PSU with an LED first, right?. I wanted to run a first test with a standard LED (20mA), checking the current limiting features of the instrument and using the data logger at the same time, so this is how a ran the test:
I've found that the current limiting for a 20mA LED works very well on Output 2 and Output 3, it is very quick, accurate and no LEDs were harmed in the process.
Well, things didn't go that well for me running the same test on Output 1. This output goes as far as 43mA on CV (Constant Voltage) mode before switching to CC (Constant Current) mode to limit the current to 20mA, here is are a graph showing the effect and the meter output.
I didn't find any clear explanation to this behavior on Output 1 in the specifications, so I'd love to reach my fellow readers if someone knows an answer to this.
Ran a similar test, this time with a 350mA LED running the same steps as the previous test:
Once more, a 350mA load works very well on Output 2 and Output 3 switching to CC (Constant Current) right on the 350mA mark, Output 1 did better this time but is not as accurate as Output 2 and Output 3 seems. Seems to me that Output 1 is not as good for small loads at the Output 2 and Output 3.
This is an awesome feature as will save us from using external wires, instead internal relays will do the work. I tested Auto-Parallel and Auto-Series mode with 3 different stepper drivers.
The current meter and the Logging features of the E36313AE36313A were not very useful in this test as they were not accurate -just for this scenario-. I used constant current stepper drivers -known also as chopper drivers-, to control the motor current, a chopper driver turns the output voltage to the motor on and off rapidly, due of the nature of the chopper drivers, the instrument's meters could not accurately determine the total current drained by the stepper driver in all 3 scenarios, this can be verified by measuring the current independently in each coil with an ammeter, this is not bad at all -do not get me wrong here-, here the E36313AE36313A excels at providing enough clean juice to make the motors work with high DC voltage and/or high DC current that may be required for this kind of tests.
I used an Arduino to provide the step pulses to the stepper drivers at different speeds, the pulses speed was regulated using a potentiometer. The Arduino is then connected to a HCPL-2200 opto-couplerHCPL-2200 opto-coupler to provide isolation from the micro-controller.
In this scenario I used a LV8727LV8727 driving a 3A/phase Bi-Polar stepper motor with at a half-step resolution.
This scenario may have triggered the Over Current protection when the stepper is at θ64 (71% power each coil, around 4.26A) but did not happen, this may be due to the fact explained before where the sensing circuit is not fast enough to detect an accurate reading of the current used at a given point of time.
Tested with 12V and 24V Vmot changing the stepper speed
| {gallery:width=480,height=272,autoplay=false} LV8727 stepper driver test |
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LV8727 idle: Ch2 Idle at 9V, note current reading is only 854mA |
Used a DRV8825 driving a 1.68A/phase Bi-Polar stepper motor with full-step resolution.
Tested with 12V and 25V Vmot changing the stepper speed
| {gallery:width=480,height=272,autoplay=false} DRV8825 stepper driver test |
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DRV8825 idle 24V: Ch2 Idle at 24V, current reading is only 266mA |
DRV8825 idle 12V: Ch2 Idle at 12V, current reading is only 454mA  |
Test with a DRV8824 driving a 0.33A/phase Bi-Polar stepper motor with full-step resolution.
Test with 24V and 45V Vmot changing the stepper speed
| {gallery:width=480,height=272,autoplay=false} DRV8824 stepper driver test |
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DRV8824 idle 45V: Ch2 Idle at 45V, current reading is only 266mA |
DRV8824 idle 24V: Ch2 Idle at 24V, current reading is only 454mA |
When testing the stepper drivers, sometimes the instrument's fan will speed up, also a switching noise can be heard inside the E36313AE36313A , depending of the stepper driver's decay mode selected and the speed of the stepper.
The Inhibit Input function lets an external input signal control the output state of all the output channels in the power supply. I've tested this option as I find very useful to have an external Panic Switch or E-Stop (Emergency Stop) when required, the following diagram shows how I wired the button to the Digital Port.
| {gallery:width=854,height=480,autoplay=false} E36313A Digital Port |
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Digital port: 3.5 mm female 4-pin terminal block connector |
Digital port: Panic switch wiring |
First, I decided to use a Normally-Open switch, then in the front panel option Utilities > I/O Config > Digital IO changed the Pin 3 polarity accordingly:
Then in the the menu Output Settings > Output Inhibit I've enabled Inhibit option Latched which will make the Inhibit signal remain latched until the inhibit input is turned Off and the output protection is cleared for all outputs.
The Output LIST allows single or multiple outputs to run in sequence, you can configure up to 100 voltage and current steps in the Output LIST window.
I didn't test much this option as I didn't find any practical scenario that I could use to properly test this feature providing useful results. I set an example where I'm executing a LIST of 7 steps. The data logger may be used while the LIST is running; this can be appreciated on top of the meter view.
It can be appreciated in the meter view that the Voltage/Current settings do not reflect any data related to the LIST steps being executed.
This instrument can monitored and controlled from a Web browser. This is probably the only feature where I completely disliked the user's experience, In my opinion, this feature needs to be improved/redesigned is it renders the instrument very slow, the Web interface is also very slow, to get the results I expected when trying to change a voltage for example, I've found myself pressing a key in the web interface and then waiting until the LCD screen emulation was refreshed in the browser before pressing the next key .
The web interface is very slow and drives the overall performance of the instrument's down, the issue boils down to how the web interface was implemented, I've found that the web interface relies 100% on the screen capture of the E36313A
Every time a key is pressed in the web interface -or every certain amount of time-, the PSU will take a screen shot behind the scenes in the background, later sending a refreshed screen capture to the web browser -trying to match the web browser LCD emulation to what the PSU is displaying-. Of course, this process is slow, and uses a big part of the E36313A's CPU, making it slower overall. This can be noticed by using the instrument's keypad with the Web interface working, it will respond and will refresh the screen at a slower pace.
Not everything is bad here, I think the web interface is good for things such as:
As a person with coding background, I wanted to test how easy/difficult was to elaborate some activities with few commands, I connected to the E36313A using a telnet session and tested few commands directly from the User's Guide, used the Web Interface's details to find the telnet port and started some tests.
Before going further, I recommend to set The Backspace key to Control-H in the Terminal > Keyboard options, this will our keyboard's Backspace key usable in the telnet session.
For a hobbyist like me who is getting his hands for the first time into a Bench Power supply, it was surprising to find that some commands in the User's Guide have syntax issues, to make this part of the RoadTest work, I've found myself spending a considerable time looking for answers online this syntax issues.
While testing this feature I realized that the instrument's error queue, which can be accessed from the menu Utilities > Error logs for errors in the remote interface, I've found this userful and the same time a little disappointing as you won't get any feedback in the telnet session -which I think is pretty simple to do to be honest-, instead if you have any error in the remote commands, you will need to head to the instrument's menu, and find what happen there to fix the issues, that kind of defeats a little the purpose of opening a remote session to manage the instrument IMO.
Here is one of the few errors I've found
APPL Ch1 5, 1
If you look carefully, the error indicator will tell you that something is not ok, but you won't know it in the telnet session, note that I've used a command directly from the User's Guide (Copy & Paste). When heading to the instruments error queue, I've found the error "Error-103, Invalid separator"
After digging a lot online, found the correct syntax for this command in the E36300 Series Programming Guide:
APPL Ch1,5,1
Another example:
VOLT:PROT MAX (@1)
Seems every error in the User's Guide goes down to a missing coma. The correct command is
VOLT:PROT MAX,(@1)
The errors I've spotted in the manual are few and were fixed by adding a missing comma. I didn't have enough time to test every single command in the User's Guide, but managed to do some work, like measuring the voltage on Channel 1:
After figuring out how the commands work I've found that they are intuitive, simple to implement and will make some activities easier for you, but if I were Keysight, I would add directly in the remote interface some sort of feedback in case of errors, that would make the Remote interface experience more pleasant in an instrument like this.
Once got my E36313A, in less than an hour found a critical bug that rendered the instrument completely unusable in whatever state it was, I think Keysight should address this with priority as this poses risk for whatever is connected to it, here is an easy way to reproduce it:
After following the previous steps, the instrument will freeze completely leaving the Output of <<step 2>> On, it wont respond to any key -including the power button-, the only option to solve this is to disconnect the mains power, after connecting the mains power again, the instrument will turn on automatically -also not good in my opinion-.
Since this instrument is software driven, I think it would be good for Keysight to implement a forced shutdown where you literally force the instrument to shut off like computers do, by holding the power button-in for few seconds. Of course first I think the critical bugs have to be solved.
Also when I was trying some remote tests with a few telnet sessions, the unit froze without any action from my part, this only happened once and I could not reproduce the issue again.
At the time of writing this RoadTest, firmware version installed in the instrument was 1.0.4-1.0.0-1.04 which matched the latest firmware available on Keysight.com
Lastly, after having some of the bugs mentioned, I expected the issues to be recorded somewhere as some kind of feedback for Keysight (or for the end user). I went to the Error queue and didn't find anything. Seems the Error queue is reserved for the self-test errors and for the remote interface only.
Unfortunately, I don't have any instrument that allows me to demonstrate with reliable numbers what I've found here but basically found two issues:
The E36313AE36313A is very powerful and brings a lot of good features with a very intuitive user interface, I think it will be great addition to any workbench. If you are a hobbyist like me, an instrument in this price segment may be a little overkill but will serve you for many years to come as it packs very good specifications and will help you in your projects with ease. I've found few negative aspects but I don't think this will take merit from a good product like this as it performs very well in what its main purposes are: providing 3 outputs with clean and stable power and extra features.
Stay tuned as I might add some extra content in the future!. Thanks for reading.
I'd like to thank Element14 and Keysight for letting me be part of this RoadTest, it's been great learning experience for me.
Top Comments
Great review @luislabmo !
Fine, I'm not alone - the software of your P.S.U also freeze if you press the back button twice.
E36313A Triple Output DC P.S. - Review
Also the voltage spikes as I showed in…
Great review Luis!
It's strange that you and others have found crashing issues with this unit yet I never ran into a problem with it freezing once when I was doing all my testing or since. Maybe I was operating…
Excellent review with a good set of tests to demonstrate the operation and use of the power supply.
Kind regards