DP832A output - Page 1
Forum section: electronics / testgear

author: blueskull
author_rank: Unknown
timestamp: January 15, 2019, 07:48:24 am
content: Are there any DP832A owners out there? I'm considering a power supply, and this has had my attention.My requirements:1. Test devices made for 5V input (test up to 5.5V, 2A)2. Power analog circuits (up to +-15V 0.5A)3. Power power circuits (up to 12V 2A, 2ch, independent)4. Current logger as a simple SMU (no 4-wire needed)So far, the contestants are E36312A, DP832A and DP832.E36311A and DP831/DP831A are eliminated for the lack of independent triple outputs. The high voltage outputs on those units are tracking-only.E36313A is eliminated for the higher rated RMS noise.So before I pull the trigger on DP832A, I need to ask the few questions:1. What is its 5V output range? It has 5.5V OVP, so can I force it to output 5.5V? I know some BK power supplies rate lower voltage than OVP, and if I set OVP higher, their output voltage can be stretched by a bit.2. What is its difference than its older brother besides the nice color display and hence the graphing capability? Is there anything in particular that is worth the $350 after resolution hack and new revision power FET upgrade?Thanks//Edit: new question added: can DP832A be hacked using the DP832 Riglol tool?//Edit2: I see it comes with all options enabled, so no hacking needed.

author: Jeroen3
author_rank: Super Contributor
timestamp: January 15, 2019, 08:24:29 am
content: Quote from: blueskull on January 15, 2019, 07:48:24 amChannel 3 shares common with the channel 2.Quote from: blueskull on January 15, 2019, 07:48:24 am1. It does not go up to 5.5 I think. Must check.2. Color screenQuote from: blueskull on January 15, 2019, 07:48:24 amYes. I bought the non-A and still have LAN and mV resolution.LAN might cause the unit to spontaneously reboot, see Rigol DP832 bugs topicEdit: Maybe look at the Rhode and Schwarz power supplies. Those are true 3 channel. For example: NGE103 or NGE103B (can't tell the difference). (€800)

author: 2N3055
author_rank: Super Contributor
timestamp: January 15, 2019, 10:17:55 am
content: Quote from: blueskull on January 15, 2019, 07:48:24 amJust to clarify, +/-30V channels have common ground. But they are full independent in control and settings and measurements (or you can set them to tracking too if needed).Please note that OVP on those is software based. Meaning, readback will measure too high voltage and will send command to shut down channel. It is slow, it can take 200 msec for it to react.For critical circuits I use external crowbar circuit..

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: January 15, 2019, 10:53:13 am
content: I have the DP832 (not A) and I like it. It's 0-32V 0-32V 0-5.3V for CH 1-3 respectively. Limitation is that Ch 2 and Ch 3 share the same ground. It's a very well made PSU and can be 'upgraded' to everything the DP832A hasexcept for the (weird) multi-color graphical display. If you relaxed your 5.5V max to 5.3V you might be there.[Edit Sep 2019] The DP832 can be changed to a DP832A using a 'magic' USB drive, the full details are inthis threadand, as is explained there, it also applies to other Rigol equipment e.g. the DG1022Z can be converted into a DG1062Z.The only thing I changed was to replace the fan with a quieter one - I have afull thread hereon that which includes fan model number and resistor value to make the fan running detection system work properly

author: PartialDischarge
author_rank: Super Contributor
timestamp: January 15, 2019, 11:22:35 am
content: I have a dp832 hacked to A, ch3 goes to 5.3V, overall very sturdy, but be prepared to change the fan, it's noisy.

author: nctnico
author_rank: Super Contributor
timestamp: January 15, 2019, 11:31:02 am
content: Quote from: blueskull on January 15, 2019, 07:48:24 amGet the E36312A or the E36313A. They are whisper quiet and accurate.AFAIK the DP823 doesn't have true isolated outputs so be sure to check that.

author: tautech
author_rank: Super Contributor
timestamp: January 15, 2019, 11:44:07 am
content: A SPD3303X-E hacked to SPD3303X might be worth a look, whisper quiet, isolated outputs, graphing and a great SET/Load display.5 min overview:https://youtu.be/H-BiphMqp5g

author: TurboTom
author_rank: Super Contributor
timestamp: January 15, 2019, 11:53:25 am
content: Vs. the SPD3303X (E) I like the option to be able to enter the voltages/currents via the keypad on the DP8xx series (despite the funny layout...). This makes dialing in parameters very quick and grants low probability for errors. A digital PSU witout a decimal keypad wouldn't be an option for me. But that's just my personal preferance (just like I won't ever get used to analog PSUs with coarse/fine adjustments, I'ld prefer one with a decent multi-turn pot anytime). YMMV

author: RoGeorge
author_rank: Super Contributor
timestamp: January 15, 2019, 11:53:51 am
content: DP832 have 3 channels (I have a DP832 for about a few years)- CH1 is a 32V/3.2A, isolated (floating), can be wired externally in series or parallel with CH2 (+/-32V or +64V) but there is NO sink current capability (all 3 channels are working in FIRST QUADRANT ONLY, positive voltage, positive current)- CH2 is a 32V/3.2A, have an internal common ground (by design) with CH3- CH3 is a 5.3V/3.2A, common ground with CH2, by design- Each channel can be operated independently- CH1 and CH2 can be set in tracking mode or independent- can be unlocked for internal voltmeters to display mV and mA resolution (without upgrade the resolution is 10mV/10mA) and other fancy software features- has CC/CV mode- linear power source (no SMPS inside)- fan is a little noisy for a quiet room at home, OK for a lab at work- very cumbersome software menu/submenu for more complex features- very good and very handy physical buttons, easy to control frequently tasks like setting voltage/current, etc., has digital keypad too, just that the number are placed in circles, which is funny but easy to use. I appreciate a lot that it has distinct buttons for V, mV, A, mA (the arrows around the main knob)- SCPI over LXI or USB- a few digital i/o for trigger/automating testing- loaded with SW features when unlocked!!! It happened to me once to see it reset and reboot out of nowhere, at a total load of about only 60W, just because I was constantly reading the voltage and current by LAN, using SCPI, for logging purposes!!! It's big and heavy (almost half a meter deep, so plan for the workbench real estate)!!! It has some problem with the common ground between channels, a voltage drop somewhere on the ground path between CH2 and CH3 IIRC, can be a problem at high currents, can be fixed by simply putting a thicker wire inside the DP832 case, near the front connectors, never bothered me but the issue is there, some design/manufacture flaw. Easy to fix but needs to remove the seal in order to do it.Hard to beat DP832 at the price/features ratio. Good quality overall (for the money), but has some childish bugs and design flaws: i.e. mine has a few 10s of mA or mV erroneous display only when close to zero, otherwise is more or less OK (but the accuracy and precision are NOT 1mV/mA, only the resolution is that good)TL;DROverall:- Great for the money in an average lab, horrible and unreliable if you look for metrology grade equipment.- Don't know about the Voltage noise/stabilization, didn't really needed that thing at home tinkering.- Will I buy that again? Yes, for my needs, in a home lab, is great. (In fact, for the next one I will look for a 4 quadrant model, in order to avoid buying an extra instrument for a controlled load, but that's just me)

author: nctnico
author_rank: Super Contributor
timestamp: January 15, 2019, 12:09:30 pm
content: Quote from: TurboTom on January 15, 2019, 11:53:25 amI agree. I have a couple of PSUs with a keypad and it is a very good way to set a PSU to the right voltage/current quickly.

author: Wolfgang
author_rank: Super Contributor
timestamp: January 15, 2019, 12:34:19 pm
content: Quote from: blueskull on January 15, 2019, 07:48:24 amHi,I have both DP832 and DP832A and I like them. Both are running trouble-free for some years now. What I also like is stable USBTMC/SCPI programmability so they can be remote controlled and automated for tests.

author: 2N3055
author_rank: Super Contributor
timestamp: January 15, 2019, 12:40:51 pm
content: Well, no PSU is metrology grade equipment. 1 mV precision on 30V ch would be 33 ppm.There are SMU-s out there with that kind of specs, but prices are huge.Rigol specify 0.05%+20mV for set and 0.05%+10mV for readout. My 831 was much better than that.So to speak colloquially, if you want to use readout for measurement, you will get same results like if you were to use Fluke 87V for measurements. For which you would need 6 instruments.If that is good enough for you it's a fine piece of equipment.If you need better than something else must be considered. E36313A is comparable in power, fully independent channels , and has slightly better accuracy specs but not much. And 3x the price.

author: RoGeorge
author_rank: Super Contributor
timestamp: January 15, 2019, 12:47:25 pm
content: Quote from: MasterTech on January 15, 2019, 12:21:34 pmMy bad, sorry.It's max 5.3V/3.2A

author: nctnico
author_rank: Super Contributor
timestamp: January 15, 2019, 01:14:07 pm
content: Quote from: 2N3055 on January 15, 2019, 12:40:51 pmAnd let's not forget the low current measurement range which gives uA resolution up to 20mA on the E36312A and E36313A.

author: 2N3055
author_rank: Super Contributor
timestamp: January 15, 2019, 01:16:40 pm
content: Quote from: nctnico on January 15, 2019, 01:14:07 pmThat is correct. That is actually the only significant plus that you would see in use, if you need such measurements.

author: RoGeorge
author_rank: Super Contributor
timestamp: January 15, 2019, 02:06:16 pm
content: A few major drawback to consider at DP832:- strange things like load constantly drawing 5mA, but CH1 meter shows 15mA. This offset happens in my DP832 only for CH1, and only for something in the range of 10mA or so.- the internal V/A/P meter indicator is bogus at very low voltages or currents. The A sensor for the panel meter is placed somewhere before the big filter capacitors, so you won't see the current flowing through the load, but the current flowing through the filtering caps + load, which may be very misleading in the mA/mV range.- the protection itself is reading the current BEFORE the output caps, so if you set the CC mode at 10mA current, let's say for a LED, but forget the voltage at some 10-20V big, when you connect the LED to the wires, it will pop like popcorn, because there was enough energy (stored in the filtering caps) to make the LED explode.It can happen to set for 20mA, but get 18A instead, abouta thousand times more!https://hackaday.io/project/7590-retardo-davinci/log/25376-rigol-dp832-power-supply-set-for-20-ma-can-kill-a-ledFig 1: Voltage drop at connecting a 1 ohm load, DP832 in constant current (CC mode) set to 20mA ^CC mode is bogus. Same for very low voltage CV mode (think FPGA here), double check with another instruments. I don't have numbers about how bad the stabilization is at very low voltages and/or currents, but my conclusion was I'd better wont use DP832 for that.

author: Jeroen3
author_rank: Super Contributor
timestamp: January 15, 2019, 02:11:13 pm
content: The Rigol also gives a glitch on Channel 1 when you turn it on with the mains switch.

author: nctnico
author_rank: Super Contributor
timestamp: January 15, 2019, 02:23:31 pm
content: Quote from: RoGeorge on January 15, 2019, 02:06:16 pmThis is normal for most power supplies. However the size of the output capacitor determines how badly a load can be damaged if you expect it to act as a current source.

author: 2N3055
author_rank: Super Contributor
timestamp: January 15, 2019, 02:42:46 pm
content: Quote from: RoGeorge on January 15, 2019, 02:06:16 pmPSU is not proper CC source. None of them, even 1600€ Keysight mentioned. They all have large capacitor on very output (all of them , not only Rigol) to ensure stability of voltage under various complex loads.There are some PSU topologies that are stable without large capacitor on output, and they will have less of a pulse but even them will have a discontinuity when switching from CV to CC mode.If you want to test LEDS you need proper CC source that is constantly in CC mode, and also has max voltage limit so you don't damage LED if you reverse it and exceed max reverse voltage.Diode testers for sensitive RF diodes actually have inputs shorted, then you connect diode, and then you remove short and ramp up voltage and current slowly to avoid any kind of transient.In this case proper procedure to test a LED would be to set output voltage to some voltage larger than Froward voltage for that LED, but smaller than maximum reverse voltage. Then you set some current in a range you want to check. Disable output, connect LED, and enable output. PSU will start from 0V and will not produce transient.Quote from: Jeroen3 on January 15, 2019, 02:11:13 pmThey all do that too. It has been discussed in detail here in forum. It was investigated and found to be induced voltage in connected grounds (scope and PSU) from switch on transient. It is not really on output, but induced in probe ground.

author: Jeroen3
author_rank: Super Contributor
timestamp: January 15, 2019, 03:28:03 pm
content: Quote from: 2N3055 on January 15, 2019, 02:42:46 pmIt is not a measurement effect. I found out with an isolated current probe and measuredcurrentwhen switching on.

author: nctnico
author_rank: Super Contributor
timestamp: January 15, 2019, 03:48:22 pm
content: Quote from: 2N3055 on January 15, 2019, 02:42:46 pmAFAIK this was discussed for the Keysight E3631xA series. Perhaps Jeroen can show some oscilloscope pictures from his measurements. If the spikes are in the double digit us (micro second) territory (or shorter) I wouldn't worry.

author: 2N3055
author_rank: Super Contributor
timestamp: January 15, 2019, 04:27:41 pm
content: Quote from: Jeroen3 on January 15, 2019, 03:28:03 pmQuote from: nctnico on January 15, 2019, 03:48:22 pmYes absolutely, I would like to see that and explanation of measurement setup. I would like to reproduce it if possible. It would be great to know exactly what is happening here..

author: RoGeorge
author_rank: Super Contributor
timestamp: January 15, 2019, 06:28:17 pm
content: For my Rigol DP832, the current spike (at the DC banana output plugs) when the mains switch is turned on is for real. To my surprise, the voltage is negative. This can be clearly seen with an analog passive microampermeter (just a galvanometer, with an indicator needle and no electronics).- The needle violently hits the out of range side of the scale when the mains switch is turned on.- Looking at the needle, it is more than perfectly clear that there is real current flowing through the wires and coming from the power source. It is not some induced switching noise.- A smaller move happens when the mains is turned off, too.- CH1's spike looks much stronger than CH2.- CH3's spike seems to beat them all.I didn't make any controlled tests, just connected a uA-meter. The galvanometer is from an old Russian cassette tape recorder, or something, 100uA full scale.While the spike is for real, it doesn't seem to have enough energy to do any damage.

author: Jeroen3
author_rank: Super Contributor
timestamp: January 15, 2019, 06:39:00 pm
content: I will redo my measurement and will report back. (24 hours)Edit (still getting back tomorrow, but could do this now):Quote from: RoGeorge on January 15, 2019, 06:28:17 pmYou'd think. Or maybe my unit is faulty. But look:

author: 2N3055
author_rank: Super Contributor
timestamp: January 15, 2019, 06:43:28 pm
content: Quote from: RoGeorge on January 15, 2019, 06:28:17 pmThanks for the detail. I will check it.

author: 2N3055
author_rank: Super Contributor
timestamp: January 15, 2019, 08:05:16 pm
content: Ok this is what I see now.After inductive spike at the beginning, there is a 300 msec event of negative going voltage on output. voltage ranges are 262,5 mV for CH1, 62,5 mV for CH2 and around 400 mV for CH3.I presume that is negative offset needed for PSU to be true 0 output, before digital part sends calibrated zero to analog part of analog board.That is very interesting, and it is there.That voltage is probably not going to damage anything, only problem is that it seems to be without current limit at the time. So if you have very low impedance on output, it can pull many amperes...It is definitely there but it probably will not damage anything because of very small voltages..I don't really care, because for years I was working with old PSU's, some of which had no output disable. So I never power up PSU with outputs connected.Of course that shouldn't be necessary, and brings me to my few real complaints to DP800 series:1. They should have put relays that disconnect outputs.(I'm thinking of making small piggyback board that will control 3 relays of the On/Off leds in enable buttons)2. OVP is in software and not in hardware and is very slow. Even in software it could be done in few msec after A/D conversion with some clever programing.3. If you setup OVP at 3V, and then go to channel and set output to 30V it will let you. Not only that, it will let you ENABLE the channel, that will send 30V to that channel for few hundredths of msec before OVP will kick in. That is easily avoidable in program. And will definitely evaporate whatever is connected to that channel.So I just presume there is no OVP on it. I use external crowbar if I think it's needed. I also make it a point to use 8V CH (CH1) for logic/low voltage stuff..

author: RoGeorge
author_rank: Super Contributor
timestamp: January 15, 2019, 08:33:59 pm
content: Quote from: Jeroen3 on January 15, 2019, 06:39:00 pmWow, that's a very convincing test!Is that a 12V/20W halogen bulb?The only incandescent light bulb I could find was a 21W/12V (auto turn signal) and a 6.3V/0.3A (small flashlight bulb size, like the ones used to illuminate the scale of tube radios). Not halogen, both were normal incandescent. Couldn't see any light, but I guess the halogen bulb will light up much faster. Or, maybe you have a faulty DP832.Don't know what is happening, but now I'm very curious to measure how much energy is in that spike.

author: 2N3055
author_rank: Super Contributor
timestamp: January 15, 2019, 09:06:37 pm
content: Quote from: RoGeorge on January 15, 2019, 08:33:59 pmThat is indeed a lot of energy..I would vote for a problematic unit. No way even my worst channel can light up a bulb.I connected 10 Ohms on output, and voltages dropped to 100mV, 15mV and 125mV...I would like to see oscillogram of voltage on that output, with and without defined load (like 10 Ohm).EDIT: Typo in mV

author: sd
author_rank: Unknown
timestamp: January 15, 2019, 09:37:06 pm
content: I have the Rigol DP832A and the higher power E36313A (I don't think there are any other differences between the E36313A and the E36312A). The DP832A is my go to lab PSU.What I dislike about the E36313A:-fan is always on, even when the PSU is off (as in soft off from the front panel). It isn't loud when it's in "off" mode but it's still noticeable in a quiet environment.-when setting current/voltage you can't use the arrows to position yourself on a specific digit, and then use the rotary encoder to make for example 10mV/100mV steps (as you can on the DP832). You either go one mV at a time using the rotary encoder, use the keypad, or spin the encoder fast and watch if overshoot like crazy if you didn't set OVP. I, for one, newer felt the need for encoder acceleration on a lab PSU.-doesn't display power for each channel as the Rigol does. You have to press the "Meter view" to see power for one channel.Nice things about the E36313A:-sense terminals on the back

author: sd
author_rank: Unknown
timestamp: January 15, 2019, 09:43:50 pm
content: No idea. If you want I can make a couple of measurements on both of them in about 2-3 days.

author: nctnico
author_rank: Super Contributor
timestamp: January 15, 2019, 10:59:50 pm
content: Quote from: Jeroen3 on January 15, 2019, 06:39:00 pmWow!I vote you have a faulty unit. To make sure you should do a measurement (using a scope) with an open circuit and the voltage across a 10 Ohm resistor. See what kind of waveforms you get.

author: RoGeorge
author_rank: Super Contributor
timestamp: January 15, 2019, 11:24:28 pm
content: On the other hand, if the spike is not limited in current, I woudn't be surprised for the halogen bulb to light up at a 0.1V spike, or alike.The inrush current for normal incandescent light bulbs can easily be 10 times more than their nominal current. If we combine that with the logarithmic sensitivity of the eye, maybe there is not so much energy required for a halogen bulb to blink slightly.I suspect my DP832 (or any other DP832) will light a halogen bulb, too, just that I don't have any halogen bulbs for the moment.

author: 2N3055
author_rank: Super Contributor
timestamp: January 15, 2019, 11:35:41 pm
content: On my 831 voltage droped 4x with 10 ohm load that is 30ish ohms internal impedance.Not enough current to light a lamp.I tried with 55W 12V lamp and it took 800 mV and 1.5A to see glow.I will try tommorow with current shunt.

author: PartialDischarge
author_rank: Super Contributor
timestamp: January 16, 2019, 06:48:30 am
content: All my channels in the dp832 produce 0.3V 0.3s outputs on startup, last one is ch2 with 10ohms.The halogen bulb video is quite strange

author: RoGeorge
author_rank: Super Contributor
timestamp: January 16, 2019, 08:05:45 am
content: Quote from: Jeroen3 on January 15, 2019, 06:39:00 pmI found a halogen bulb, but it's not 20W/12V, it's 35W/12V. Can not see any light, not even in a pitch black room. The 35W one starts to glow, very, very faint at about 0.8A/0.7V. I'll keeping looking for a 20W/12V halogen bulb. I suspect your DP832 is either from the first batch, the ones with a small radiator, or simply it's a defective unit.What year and board version is your DP832?Is it the model with a small, or with a big radiator?

author: Jeroen3
author_rank: Super Contributor
timestamp: January 16, 2019, 07:21:26 pm
content: Quote from: Jeroen3 on January 15, 2019, 06:39:00 pmAs mentioned, I redid my measurement.Please excuse the crude drawing, drawing on a tablet is still new for me.I must conclude channel 1 behaves odd. It gives 0.7 Watts for around 250 ms. The other channels do not.I'll ask if this is warranty or repairable. (Bough it 15 months ago)

author: nctnico
author_rank: Super Contributor
timestamp: January 16, 2019, 07:24:46 pm
content: That is definitely broken. A similar problem made Keysight to recall all the 3631xA power supplies and fix them.

author: RoGeorge
author_rank: Super Contributor
timestamp: January 16, 2019, 08:26:13 pm
content: Wow again! My DP832 doesn't act like that.There is a 3rd wire connected at the DP832, in the green banana plug. I can not see in the pics where it is connected on the other side.1. Where to does that wire go?2. What happen when you measure CH1 with the ground wire (green banana) disconnected?

author: Jeroen3
author_rank: Super Contributor
timestamp: January 16, 2019, 09:04:21 pm
content: The wire going away is ground for my USB switch. I grounded negative of the supply to not have common mode glitches.Removing this makes it worse.Edit: blueskull, sorry for hijacking your topic.

author: 2N3055
author_rank: Super Contributor
timestamp: January 16, 2019, 09:19:13 pm
content: Warranty in EU is 3 years.. I would invoke it. Let us know how it goes.

author: RoGeorge
author_rank: Super Contributor
timestamp: January 16, 2019, 09:44:45 pm
content: That grounding problem is strange. My hope is that the DP832 is OK, but some other power supply from other equipment is faulty.Let's do one last test:- disconnectallwires (USB, LAN, I/O, all), except the mains power cord- connect only the halogen bulb at CH1 of the DP832. No oscilloscope, no other instruments, just the two banana plugs and the bulb (one banana at +, one banana at -)- no other wires or external jumpersDoes this minimal setup still flashes the bulb?

author: TurboTom
author_rank: Super Contributor
timestamp: January 17, 2019, 01:00:09 am
content: I just did some switch-on transient tests with my two DP800 series PSUs (811 and 832, both "liberated"), recent H/W and both F/W 1.16 beta. I checked voltage with a 10 ohms resistor across the terminals and current with a dead short via a Tek P6042 probe ("oldie but goldie" and definitely better than nothing at all...). I'ld say the 832 is unproblematic while the 811, wellIt's amazing though how much the channels of the DP832 differ.

author: nihtila
author_rank: Regular Contributor
timestamp: January 17, 2019, 08:54:01 am
content: I have DP832 and E36312A I won from a Keysight contest. Need to check my DP832 output as well..Anyway, Keysight has become my go to instrument because it is soooo much quieter. Yes it's annoying that the fan is always on but I switch off my whole bench when not in use. I only use the Rigol when I need the extra power, or if I need more than 3 outputs like in the current project. Both have their quirks; while Keysight looks more professional it has had loads of bugs and the usability is still not as good as you would hope from a unit in that price class (miles better than the old E3631A though!). Anyway, I maybe like to use Keysight more now but would still choose Rigol because of significantly lower price tag.PS. Keysight's low voltage output can go a bit over 6V, 6.1 or so - may be enough for a 5V LDO.

author: Jeroen3
author_rank: Super Contributor
timestamp: January 18, 2019, 07:58:45 pm
content: Not the answer I was hoping for...

author: RoGeorge
author_rank: Super Contributor
timestamp: January 18, 2019, 09:05:10 pm
content: Quote from: RoGeorge on January 16, 2019, 09:44:45 pmI am very curious about this ^. Can you check if the bulb still flashes when there are no extra electrical connections, only the power cord and the halogen bulb, please?No need to waste extra time for visual evidence, a simple "yes, still flashes" answer will be more than enough.

author: bson
author_rank: Unknown
timestamp: January 19, 2019, 03:02:05 am
content: I've had it for 3 or 4 years now. It's pretty big and noisy for its power; the Keithley 2231A-30-3 with similar specs, for example, is the size of a bench DMM. It had a whole slew of firmware bugs when new, which are fixed now. It's very easy to calibrate yourself when needed with just a basic multimeter, mine needed updated calibration data when new, but has retained 1mA/1mA readout accuracy since with that initial calibration. Not sure what they do in the factory, but it was pretty poor. Those scripts we wrote are still around and get it calibrated. The 5V output is slightly more accurate that the higher voltage ones. CV/CC works like they should, OVP and OCP can be disabled if a nuisance with some particular load.The display is nice, the silly keypad is well, silly, but at least it's a keypad.I think it's fine budget bench tool, apart from the bulk. It does the job. I wouldn't trust it unattended 24x7 though, for any production use.It can measure rms and averages fine, but has zero ability to analyze or track power transients.

author: nctnico
author_rank: Super Contributor
timestamp: January 19, 2019, 11:46:26 am
content: Quote from: bson on January 19, 2019, 03:02:05 amIsn't that some kind of rebadge? BK Precision has a very similar looking PSU. Still the Keithley is pretty cheap.

author: Jeroen3
author_rank: Super Contributor
timestamp: January 19, 2019, 02:29:43 pm
content: Quote from: RoGeorge on January 18, 2019, 09:05:10 pmYes. Without any ground (just phase and neutral) it still does. Short circuit current of 2.5A for 280 ms. Or similar in a 10 Ohm of previous post.With or without ground does not matter much. The supply leaks 0.2 mA.I was looking to see if I can perform a soft reboot. But scpi does not seem to offer this.

author: bson
author_rank: Unknown
timestamp: January 20, 2019, 07:37:40 am
content: Quote from: blueskull on January 19, 2019, 03:12:39 amDoesn't surprise me... (I meant audible fan noise.)It's possible the Rigol has slightly better specs and precision, though the Keithley is fully floating on all outputs - but the K sure wins on size and (fan) noise! This might matter if bench space is at a premium (like it is for me), and if you already have a precision supply or just don't need one.

author: s8548a
author_rank: Regular Contributor
timestamp: January 21, 2019, 12:15:12 pm
content: Quote from: blueskull on January 20, 2019, 07:45:15 amsorry for an off topic noob question.What kind of applications needs like these low psu noise? is there any specification/document available regarding different PARD requirements for different applications?

author: nctnico
author_rank: Super Contributor
timestamp: January 21, 2019, 12:55:03 pm
content: A low PSU noise helps when working on analog circuits. Chances are you are looking at the signals from the circuit and not the noise which the PSU pushes into your oscilloscope.

author: Wolfgang
author_rank: Super Contributor
timestamp: January 21, 2019, 02:06:32 pm
content: Quote from: s8548a on January 21, 2019, 12:15:12 pmA field that nees VERY low PSU noise are precision oscillators. All the PSU noise and ripple can show up as unwanted phase noise or sidebands in the oscillator output.

author: stroh90
author_rank: Newbie
timestamp: January 21, 2019, 02:20:30 pm
content: I have a DP832, bought it 4 years ago.It also has horrible output spikes on powerup. Batronix and Rigol claimed it was normal. I haven't bought anything from Batronix or Rigol since.Why people still consider this piece of junk is a mystery to me. It has many documented problems.However, if you want an expensive, noisy battery charger, it works well enough.

author: glarsson
author_rank: Frequent Contributor
timestamp: January 21, 2019, 02:31:06 pm
content: Why blame Batronix? They were correct that this flaw is normal for this PSU.

author: stroh90
author_rank: Newbie
timestamp: January 21, 2019, 03:58:41 pm
content: Ermmm…Are you saying that retailers have no responsibility for the products they supply??

author: glarsson
author_rank: Frequent Contributor
timestamp: January 21, 2019, 04:05:02 pm
content: It depends on what you asked them. If you asked them if this was normal you received the correct answer. If you asked for a refund or similar then you might have reason to complain depending on the circumstances.

author: nctnico
author_rank: Super Contributor
timestamp: January 21, 2019, 04:28:39 pm
content: Quote from: glarsson on January 21, 2019, 04:05:02 pmSome suppliers are very quick to say a problem is normal behaviour. Overshoot on a power supply when it is turned on is never normal behaviour -period- so in this case the answer from Batronix was misleading.

author: MrFox
author_rank: Contributor
timestamp: January 21, 2019, 05:44:42 pm
content: I got a dp832 a few months ago, despite knowing before hand about the limitations at cold-boot from the mechanical switch. It's a compromise to be aware of, I guess. Same for the big output capacitance, which needs to be taken into consideration when using it for CC.I haven't found any other PSU with the capabilities I needed unless I pay two or three times the price. And for me in canada the rigol distributors (electro-meters) are the most amazing people I ever had to deal with for support and claims.I would have prefered the keysight, but it's $2000 CAD versus $600 for the rigol.

author: netdudeuk
author_rank: Frequent Contributor
timestamp: January 21, 2019, 07:08:30 pm
content: Quote from: MasterTech on January 15, 2019, 11:22:35 amDP832 to DP832A ?

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: January 22, 2019, 05:33:38 pm
content: Quote from: netdudeuk on January 21, 2019, 07:08:30 pmI think he means that everything but the (weird) display format is as per the A. Google 'riglol' and see that there's a site that can give you the keys needed to turn on all A-style features but the display stays the same as the non-A version.

author: ledtester
author_rank: Super Contributor
timestamp: January 22, 2019, 06:33:46 pm
content: Here's another opinion for your consideration...