Hantek PPS2320A review - Page 1
Forum section: electronics / testgear

author: kedwards22
author_rank: Newbie
timestamp: January 01, 2015, 08:21:29 am
content: Haven't seen too many reviews of the Hantek 2320A so here's what I've found.First the bad. The unit I received had a problem, the fan screwed to the back panel had it's negative wires trapped and shorted to the case. The fan turned on whenever any output negative was grounded. This was a simple fix but it's worrying that it wasn't found during factory testing.The power toroidal transformer mounting plate screws were also loose. There's another review where the transformer had come unattached and caused more damage. In front of the fan, there's 2 heat sinks mechanically strapped together by a piece of PCB across the top. The screws holding this were also loose. It wouldn't be a problem but the rear USB board is only a few mm's away from the heat sink and any movement could cause a short. Another possible mechanical issue is the carrying handle. It feels like it won't hold the units weight. The beeper is too loud, it can be disabled, but the setting gets forgotten at turn off.Electrically, the biggest problem is channel 3 turn on. Channel 3 is a fixed 2.5V, 3.3V, or 5V, 3A output selected by a button on the front panel. Unlike channels 1/2 that have an output enable button, channel 3 turns on and off with the units power switch. At turn on, channel 3 goes immediately to a regulated 5V for 20ms, then drops to a regulated 3.3V for 800ms, then 2.5V for another 20ms, then after almost 1 sec, it goes to the voltage set at the previous turn off. Watch out if you're powering 3.3V logic. I'm probably not going to use channel 3 too much ,but if I do, I'll probably add an output relay to switch it with the other outputs.The unit wasn't calibrated very well. A calibration document is available on the web, it wasn't included with the unit. Channels 1 and 2 are set in software by calibrating at 1V and 32V, CV mode and 100mA and 3A CC mode for each channel. Calibrating to 0.9958V and 31.974V got better accuracy over the range, about +/-20mV for 0V<Vout<28V and +/-35mV for 28V<Vout<32V. There's 2 micro controllers, C8051F410, I think the unit uses their internal DAC's. The read back voltage tracks with the set voltage although they can be calibrated separately. Channel 3 is set internally by multi-turn pots, one each for 2.5V, 3.3V and 5V and one for current. After adjustment, the settings have been stable so far.In parallel mode both channels share the current limit. When the load is greater than Ilimit/2, one channels shows CC the other CV, but it oscillates between the 2 so the current read back is unreliable. The output voltage remains stable, so this is more of an inconvenience.The firmware is a bit unstable. It has an occasional control lockup, powering up in a different setting to power down and CH1/CH2 select button putting the output into parallel mode. The PC software for USB control is fairly basic but does allow voltage and current sequencing. Some warnings still come up in Chinese.Now the good. Internally, the boards are well built, re-flow soldered and very clean, I can't see any obvious hand soldering. All the larger components are hot glued. The transformer is a shielded toroidal with 110V and 220V options although my unit does not have the change over switch on the back. There are separate heat sinks for channels 1 and 2 very similar to the Atten 3205 unit. Each has an over temp switch, 2 power devices per channel, a bridge rectifier and a single device to thermally control the fan. Strangely, I can't see any heat sunk device for channel 3.The unit operates very much as expected, I haven't had to open the manual. The voltage and current set controls are quick and easy to use. They are speed sensitive. A slow turn adjusts the least significant digit, turning faster makes larger changes. Pushing the control steps through the digit to be adjusted. When the output is off, the displays show Vset and Ilimit. 4 memory buttons recall voltage and current setting only for the channel selected. It's very simple and straight forward to operate.Channels 1 and 2 turn on seems to be software controlled since it is exponential over about 60ms and is load independent, so there is no measurable over-shoot. All other parameters, load reg, noise and ripple are within spec, as best as I can measure.Overall, for the $200 US I paid, it's OK, and probably as good as you can get for the price, but better firmware and mechanical assembly is needed before I would recommend it to others. If you did buy one, I'd suggest a US supplier so you return it since the build quality is questionable.

author: picitup
author_rank: Regular Contributor
timestamp: April 20, 2015, 01:59:53 pm
content: HiI've just bought one of these from eBay in China. I live in the UK. I was very impressed with the following specs:4 digit voltage and current displayprogrammable via pcdata logginguser calibrationuse of CH1 and CH2 in series, parallel or tracked modeDigital speed sensitive controlsTriple CH3 output of 2.5v, 3.3v and 5vUnfortunately, CH3 can only be powered on and off with the mains switch and when you turn mine on or off, you get a 5v spike, followed by 3.3v then down to 2.5v as described in the post above.I then tested CH1 and CH2 with a 35w 12v light bulb, so just shy of 3 amps. I set the voltage on CH1 to 12v and the current limit to 0 and connected the bulb. As expected, the voltage dropped to 0 and CH1 went into CC mode. I gradually increased the current limit on CH1 and as expected, the current gradually increased, as did the voltage until 12v was reached and the bulb was full brightness.Not so good with CH2 though. When the voltage reached 6v, the CH2 voltage and current displays flickered randomly and the LEDs indicated both CC and CV mode. I carried on increasing the current and after a short while the CH2 displays stabilised and showed 12v. But... my multimeter said the voltage output was 6v and the bulb was not full brightness so CH2 is duff.I can't check the series/parallel/tracked modes while CH2 is duff, so that will have to wait.I'm still negotiating with the seller who, despite me sending a number of videos of the issues, is denying there is a fault. The cost of return to China is very high (GBP £76.00 - 6.9KG) and eBay tells me the seller must pay this as it's faulty, despite the seller's listing which states the buyer pays for returns.It seems that seller's returns policies can be overridden by local selling laws when selling internationally. Here in the UK we have "Distance Selling Regulations" which apply when you're not physically present for the purchase so they win over the seller's policy. One to note when posting abroad!I'll update this page if and when I make any progress.Kind RegardsSteve---------------------------------------------------------------------------------------If you know what you're doing, the you're not learning anything.

author: picitup
author_rank: Regular Contributor
timestamp: April 28, 2015, 08:16:46 am
content: Just a quick update on this. The seller kept refusing to comment on the CH2 video I supplied showing the crashing of the displays and wrong output voltage. I don't think I can post videos up here, but I've attached a couple of photos.On the subject of CH3 overshoot, I've attached a photo of my scope set at 1v/div and 1s/div and you can see the overshoot on power off and on when the PSU is set to 2.5v. Rather worryingly, in an email from the supplier, they told me that this is normal behavior and other manufacturer's power supplies do the same! Their recommendation was that you disconnect your low voltage circuit from the PSU before powering on or off! So what if you make a mistake? What if the power fails or the fuse blows? Bye bye low voltage devices.I emailed Hantek on the 17th April with a copy of the scope trace asking them to verify it is normal, but they haven't replied yet.After threatening to escalate the case to eBay, they gave me a USD $100.00 refund so I'm happy. The next thing to do is hopefully fix CH2 and also design a fix for CH3. For CH3 switch on I could connect it in with the output button circuit, then it could settle before the output is turned on. For switch off I could Hmmm.. Thinks...As the warranty will be void, I'll change the colour of some of the LEDs as the sea of red can be confusing for someone of my mental capacity.Any road up, I 'll have a poke at it in the next week or so and hopefully have a fix for CH2 at least. I'll report back anything I find with pics.CheersSteve

author: picitup
author_rank: Regular Contributor
timestamp: May 03, 2015, 03:35:48 pm
content: Another update....I spent the morning on this and have made a little progress. I stripped the unit down and the first thing I found was a cap that had been smashed by the person installing the fan. There were also lots of solder splashes where hand soldering had been carried out, but I didn't manage to prove that any of these were short circuit so the PCB resist was doing its job.I did find a broken track on the base of the first power transistor on CH2 and I hoped it would fix the problem and it did, even if partially.Now when I do the lamp test, the voltage and current do not flicker randomly, although at just over 6v, the display continues to show an incrementing voltage, but on the multimeter is still reads just over 6v. This continues until around 9v when a relay clicks and switches in another tapping. From that point, the voltage reading on the PSU is correct, all the way up to 32v so my problem is with the circuitry associated with the 1st tapping on CH2.As you increase the voltage, relays can be heard at 9v, 15v and 24v. The mains transformer is toroidal and has a number of tappings as follows:15-0-15v15-0-15v0-10v0-10v0-8-24-40v0-8-24-40vIt also has 2 primaries at 110v each. These are hard wired in series in my PSU to make the 240v here in the UK. On the back of the PSU, there is a sticker which covers a cut-out for a switch so I guess it they used to do a switchable version for 110/240v.Under no load, the output of CH2 is as expected and the first tapping range 0-9v displays the correct voltage. Under high load, the PSU display parts company with the multimeter at around 6v. Under lower load, it parts company at around 7v. When the PSU display parts company with the multimeter, the CC lamp flickers which I guess is correct as the measured output voltage is less than that set.That's all for now. To trace the circuit, I'll need to take the heat sink off as some of the tracks are underneath and you can't access some of the componentsOn the heat sink are a pair of TIP35C (25A) power transistors and an RS808 bridge rectifier (8A) and the switching relays are Fl-3FF-S-X_Relay which are 12v change over PCB relays.That's it for now. If I make any more progress I'll post it up.CheersSteve

author: picitup
author_rank: Regular Contributor
timestamp: May 03, 2015, 06:42:55 pm
content: Well after putting it all back together, I decided to take it all apart again. There are 4 relays on the power PCB, 2 for each channel. They switch in different tappings for the voltage ranges.I decided to put an LED across each of the relays and monitor the input AC voltage to the RS808 bridge rectifiers.The results from CH1 (which works ok) were:0-9v = 17vac9-15v = 26vac15-24v = 36vac24-31v = 43vacNot so good with CH2 though:0-9v = 8vac9-15v = 26vac15-24v = 26vac24-31v = 43vacThen I found the problem: as mentioned above, there are a pair of multi-tap windings:0-8-24-40vThis is correct for CH1 but for CH2 the voltages are:0-17-24-40vSo the first tapping is faulty. I did some resistance measurements in case they had just used the wrong colours, but the 0-24 and 0-40v tappings have the correct resistance but the 0-17 is wrong.I confirmed this by exchanging the CH1 and CH2 plugs and once changed over, CH1 exhibits exactly the same fault that CH2 displayed.So now I'm stuck. I did consider taking the wrapping off the toroid to see if I could see the mistake, but I'm worried I might kill it.Bummer.Has anyone in the UK got a faulty PPS2320a I could ravage?

author: Ghydda
author_rank: Regular Contributor
timestamp: May 03, 2015, 09:52:59 pm
content: ...and this is why I never buy Hantek or similar shitty chinese brand testgear.OMG this so requires<-- double facepalm

author: picitup
author_rank: Regular Contributor
timestamp: May 04, 2015, 09:23:53 am
content: Well I can't really argue with that :-). I'm amazed the transformer is incorrectly wound - I wonder how many other units have the same fault.The eBay supplier kept repeating in every email that "All units are tested before they leave and can work well". I guess I had access to more sophisticated test equipment ie a 12v light bulb from my bathroom!The up sides are that at the full price of £140.00 you can't find anything even close in specs. If you take off the £70.00 refund it's worth some of my time to fix it. That is - if I can!I'll do another update if I can work out how to progress.CheersSteve

author: Kevin.D
author_rank: Frequent Contributor
timestamp: May 04, 2015, 02:13:35 pm
content: Quote from: picitup on May 04, 2015, 09:23:53 amHiCan I ask where are these on sale for £140 ? I can't find them for less than ~£200 (UK delivered)Given the specs they have given for these (triple output, 30V 3A ,4 digit meter's) that would seem to be a good buy at that price (that is as long as your unit isn't typical of the build quality of these).

author: picitup
author_rank: Regular Contributor
timestamp: May 04, 2015, 04:31:24 pm
content: Hi yes the ebay seller is picarduino and the item number is 331240175578. Picarduino are actually Sure Electronics as my sample videos were sent to picarduino@sure-electronics.com. I can't recommend them as a seller as they played hard ball right to the end and refused to comment on the CH2 fault. In fact, when I sent a scope video of CH3 overshoot, they asked me to send another video using a multimeter! I'm guessing they were hoping it wouldn't show up on the meter, but it did display on my UT61E so tough luck on them.The price is USD 208.00 + USD 19.00 for shipping. You can also make an offer and I got USD 5.00 discount. Actually I did also get stung for 30 quid VAT import as they use a proper courier. Mind you, it arrived in about 5 days.I think they probably hate my guts, but I thought I would ask them if they can supply me with a replacement transformer. Obviously I would need to pay for this out of my refund. I wonder if it's 70 quid lol!I'm going to draw out the transformer tappings/relay circuit tonight and am wondering if I can rewire CH2 tapping switching circuit to make it work properly with the erroneous voltages.Actually I forgot to mention that I designed and fitted a 2KHz notch filter for the horrendously loud buzzer. It was made from a 1cm round blob of blue tack which I stuck over the hole.That's all for now. I'll post up any progress as it happens. Hang onto your seats.CheersSteve

author: thm_w
author_rank: Super Contributor
timestamp: May 05, 2015, 12:52:11 am
content: Is the toroid built such that you could wind an additional winding on the outside? To use in place of the faulty internal one.Odd.

author: picitup
author_rank: Regular Contributor
timestamp: May 05, 2015, 08:43:17 am
content: Hi thm_wThanks for your suggestion. I did consider unwinding the CH2 tapping and soldering a tap, but if it's beneath other tappings it seemed too mammoth a task. You asked how the toroid was built - did you mean does it have a hole in the middle - the answer is yes so I could wind another tapping on the outside. I've attached a piccy of it.OK here comes the dumb questions if I add my own tapping:How would I know what gauge wire to use for the 3 amp output?To gauge how many turns, would I do say, do 10 turns, measure the voltage and then multiply the length up?Funnily enough the supplier hasn't responded to my email requesting a replacement. Could be he's too busy laughing.CheersSteve

author: Richard Head
author_rank: Frequent Contributor
timestamp: May 05, 2015, 09:23:14 am
content: Un-fu#*believable! How can such shitty products even exist. I must remember to steer well clear of this crap.

author: picitup
author_rank: Regular Contributor
timestamp: May 05, 2015, 10:18:08 am
content: Hi well I can't really argue, apart from there is nothing else with the same specs even close in price. For a start most triple output supplies have a fixed 5v for the 3rd output which isn't much use to me as I mostly use 3.3v devices. This one has 2.5, 3.3 and 5v. It's hard to find a PSU with 4 digit display and also one that can be programmed by the PC and will support data logging. On top of this, the 2 variable channels can be independant, series, parallel or tracked to give:2 x 0-30v @3A1 x 60v @3A1 x 30v @6aI spent some time searching for a PSU with this spec - I challenge anyone to find something equivalent even close to the price.Oh well, I've made my bed so now I'll have to lie on it.CheersSteve

author: picitup
author_rank: Regular Contributor
timestamp: May 05, 2015, 08:14:01 pm
content: Hi AllJust a quick note to say I've managed to fix CH2 and it seems to be working fine. The fix was to add a relay and 3 diodes and only cost £3.00. I'll post up the full solution tomorrow as I have an open bottle of whiskey.Next on the list is to fix the CH3 overshoot and order some pretty coloured LEDs for the front panel.CheersSteve

author: gredgreg
author_rank: Newbie
timestamp: May 06, 2015, 12:55:15 am
content: Hi Steve,Contemplating buying this unit for a while now but with lack of clear reviews i was unable to make a decision. I understand that any unit that promises so much at such a low price will have some issues. In this regard your posts on debugging this PS has provided me a much clearer picture on what to expect from this unit. Eagerly awaiting your next update.Gred

author: picitup
author_rank: Regular Contributor
timestamp: May 06, 2015, 08:18:58 am
content: Hi GredThanks for your positive comments. I did wonder why picarduino are £60.00 cheaper than everyone else - maybe they are selling items with faults?Now onto the interesting bit. I took a break from painting yesterday and spent an hour tracing the tappings relays (K3 and K4) circuit. This circuit switches different tapping from the transformer to provide various AC voltages for the input to the channel. I soldered LEDs across the coils and increased the voltage and the LEDs showed there are 4 states which are both off, one on, one off etc. Well it might be a relay, but this is binary so I mapped out a couple of truth tables.If you look at the circuit, each relay is driven by a C945 NPN transistor. The coils are 400? so at 12v = 30mA. If you look top right at J7, (CH1 OK taps) this part shows the different tapping voltages for CH1 which are correct. In the centre at the bottom you can see the actual tappings for CH2 (CH2 duff taps) and you can see that the incorrect tapping is tapping 2 which should be 8v but is 17v.I was hoping that with a bit of jiggling with the wiring from the transformer, I could get all the right voltages supplied to the channel, but not so. If you move a wire, you alter another tapping combination and that voltage range will not work.On to the truth tables. The table labelled "CH1 OK" shows the correct operation of CH1. It lists the various voltage ranges, the states of relays (should be K1 and K2 for CH1 oops), the output taps connected and the resultant voltage.On to poor old CH2. The ranges with ticks next to them are OK and the ones with crosses are incorrect. If you look at the 0-9v range, the difference between 24 and 17v is 7v. This should be 17. This also showed up another error which I hadn't spotted which is the 16-24v range has an output of 23v instead of 32v.I knew the range 0-9v had a problem as output voltage under load will only go up to 6v, stick there until the next tapping switches in at 9v. I was now concerned that the top of the 16-24v range would tail off at the top end. So... out come the 12v 35w light bulbs. I put 2 in series and connected them to CH2 and increased the voltage while checking the output with a multimeter. The real good news is that it worked fine. Not to forget that after full bridge rectification and smoothing the DC voltage on the other side of the rectifier would be approx 24 x 1.4 = 33v. So this is clearly enough to power the channel at full load.OK so now we know we only have one problem which is they irritating tap 2 which is 17v instead of 8v. You've probably already spotted that the voltage between tap 1 and 2 is 17v and that is the voltage that I wanted. Also if you look a the table "CH2 duff" you can see that all combinations work apart from when both relays are off or 00 in binary.Can you see where this is going? The relays on the diagram are showed with power off or 00. K4 NO already goes to tapping 1 (0v) so there's a start. All I need to do is switch K3 NC from tapping 4 (40v) to tapping 2 (17v) when both relays are off (00) and if either relays is on (01 10 11) then it need to be switched back to the original tapping 4 (40v).There's a prize for spotting the NOR gate. I thought a little about adding some discrete logic, but realised I could do it with a relay and a few diodes. I spotted my local electronics store was open until 8pm so I zoomed over there and bought a couple of 12v 10A PCB relays and a few 1N4001 diodes. Funnily enough the relay was the exact same spec as the ones in the power supply, reinforcing my view that everything's made by one man in a shed in Taiwan and then relabelled.K3 and K4 are driven by a C945 transistor. This has a max collector current of 150mA. The K relays are 400? so 30mA. This means I can use the C945 to drive another relay. So..... I added my new relay (K5). One side of the coil goes to +12 like the other relays then the other side of the coil is connected to two 1N4001 diodes. The other side of the diodes go to each of the C945 collectors.Now, when either transistor (relay) is turned on, K5 is turned on. The connection from K3 NO was then wired to the CO contact of K5. When the K5 is off (0-9v range), it connects K4 NO to tapping 2 (17v). When K5 is on (any other range) it connects K3 NO to tapping 4 (40v).I hope the above makes sense, but if it doesn't let me know and I'll include a schematic.Then I attached a 12v 55w bulb to CH2 along with a multimeter and gradually increased the voltage. And..... It worked perfectly!!!I don't want to appear too smug but I am. Total cost? Just over £3.00. Total time? well, er...Next thing is to test all combinations of parallel, series, tracked etc. The series output goes up to 62v and I can't do this of an evening as I don't have enough bulbs to hand and removing them from the bathroom when people want to shower will cause family tensions :-)I'll report back when I've tested all the modes.So why did I buy 2 relays? I'm hoping to fit the second one to the CH3 output. It will work with the output button and will hopefully get over the overshoot issues mentioned above.If you've read this far without falling asleep, well done.CheersSteve

author: picitup
author_rank: Regular Contributor
timestamp: May 06, 2015, 11:06:54 am
content: OK just another quick update. I should be painting, but no-one's here to check up so I had a play.I tested the outputs in series and parallel modes. In series you should get 60v @3A and in parallel you should get 30v @6A. Due to a limited number of bulbs, I couldn't check entire ranges. Now I really want an electronic load.In series mode I attached a 12v bulb to the -ve of CH2 and the +ve of CH1. I then increased the voltage and checked it on my multimeter. All good up to 12v @ 3A. Then I repeated this with two bulbs in series (24v @3a) then 3 bulbs (36v @3A), 4 bulbs (48v @3a) and 5 bulbs (60v @3A). All ranges works and the psu displays were accurate.In parallel mode I wired 2 bulbs in parallel (12v @6A) then 2 series sets in parallel (24v @6A) then 3 series sets in parallel (36v @6A) but couldn't do 60v as I ran out of bulbs.All tests on all ranges worked well and the PSU tied up with the multimeter.Not surpisingly, the fan kicked in a few times. I didn't leave the connections on for a long time as the case was off the PSU and I'm not sure the air flow past the heat sink will be adequate with it uncovered. The fan is something else. It's very loud and I think i could feel my beard being pulled towards the PSU. Luckily it's not on all the time, apart from when you connect loads of 35w bulbs to it.I'm starting to become very pleased with my purchase.I've posted up a couple of piccies to show the tests. You can see the rough setup, but unfortunately the PSU display doesn't show up too well.CheersSteve

author: picitup
author_rank: Regular Contributor
timestamp: May 07, 2015, 01:43:37 pm
content: Next on the list was to address the CH3 overshoot (see above post). I unscrewed the output PCB (see pic). You can see 2 heavy gauge wire coils on the PCB and these are the output shunts for CH1 and CH2. CH3 shunt is smaller and is the grey 0.12 ohm resistor at top centre. You can see 3 black relays in the centre and was hoping that one of them would be the output switching relay. I could then wire another relay in parallel to switch CH3 on.But not so lucky. I soldered LEDs onto the coils and none of them turned on with switching the output on and off. I then experimented with the parallel/serial/tracked modes and this showed that's what the relays are for.It turns out, there's no output relay. I then looked at the the Output LED on the front panel. Maybe I could wire to this. Unfortunately it's not that simple as all the LEDs are controlled by 74 series shift registers and are strobed.I'll have a further think about this. Maybe I could wire a 555 1 second monostable to the permanent 12v relay supply which then turns CH3 output on after a second delay.Hmmm.. thinksCheersSteve

author: picitup
author_rank: Regular Contributor
timestamp: May 08, 2015, 12:10:04 pm
content: Well nothing too taxing today. I decided to change the LED colours on the display panel. I had some trouble photographing the front panel as it's strobed and my phone camera would only catch 1 or 2 LEDs which were on at the shutter time so that picture is a screen grab of a video.I've attached a piccy of the layout and a couple of pics of the display board for reference.I'm still thinking about the CH3 overshoot on power on and off and I'll post up as soon as I can think up a good solution.CheersSteve

author: mmark
author_rank: Contributor
timestamp: June 23, 2015, 09:26:22 pm
content: Great review and great details on how to fix it.I just want to add another data point. I got my PPS2320A a while ago from Circuit Specialists in the US and my unit does NOT have the issue reported from Picitup on Ch.2. I just tested it and mine does 3.1A at 6/7/8/8.95 and 9 V without any problem on Ch.2 (only my home build DC load starting to smell funny after staying at 8/9V at 3A for a while....).I haven't used Ch3 much so far, but I would be interested in a fix. I would assume one could add a relay to the output which is somehow switch on/off with the output switch.Regards,Mark

author: picitup
author_rank: Regular Contributor
timestamp: June 24, 2015, 10:58:54 am
content: Hi MarkThanks for your feedback. Good to hear your CH1 and CH2 work ok. I did put some thought into fixing CH3 but now have got waylaid to more domestic duties, so it's on my to-do list.I had a few thoughts at the time which were:Add a relay which switches on for a few seconds on power up and off immediately on power off. This could then interrupt CH3 during switch on and off which are the dirty times.Add a heavy duty zener to the output which is matched to the voltage I've selected.I did consider adding a relay in parallel with the CH1 and 2 output relays and that would work great for switch on, so long as you wait a couple of seconds before you press the output button, but this wouldn't help with powering off of the mains and the associated spikes then.I did consider tracing the CH3 circuit and clamping the voltage low at the control source, but ran out of time.If you come up with a solution, I'd be very glad to hear it as I'm sure would the other owners.CheersSteve

author: kedwards22
author_rank: Newbie
timestamp: June 27, 2015, 08:41:54 am
content: I don't see a problem on CH2 either, you must have been the lucky one. If you need a high power load for testing, a toaster works quite well, 1 slice or 2 gives some adjustability. Not joking, a 110v, 1500W toaster provides a couple of useful high power resistors, not sure about a 240V version. I'm just living with the CH3 problem and I've only used it at 5V so not such an issue, but would be interested with any fix you come up with.

author: SeanB
author_rank: Super Contributor
timestamp: June 27, 2015, 08:55:22 am
content: 2 slice toaster (the old fashioned type with mica sheet and nichrome elements, not those fancy quartz tube ones) on 240VAC has 3 elements, 2 single sided and which are wound to be non inductive, ands a single double sided one that is slightly inductive. All 3 are typically wired in series, so the outer ones are roughly a 60V unit each and the inner a 120v one. Each will have the same rated current, typically 10A, so they are pretty good for a power supply test up to 60V and, depending on how you connect them, 20A of current. Overload capacity on them is reasonable, you can go to double for around 5 minutes before they burn out. Just note the internal glass covered wiring inside is typically a steel wire, not copper.

author: ErikTheNorwegian
author_rank: Frequent Contributor
timestamp: October 24, 2015, 09:06:03 pm
content: Hi,excelnt tread!Thinking to buy a PPS2320A from the US..But Circuitspecialists dont mention if the unit they sell can be rewierd to 220V.. do anyone of you know if t can be done with the unit they sell? There is a label over the 110/220 switch hole on the back in the picture of the unit they sell.. but has the trafo posebilety of running 220 ?regardsErikNorway..

author: picitup
author_rank: Regular Contributor
timestamp: October 25, 2015, 09:53:41 am
content: Thanks ErikI couldn't guarantee that the one you're looking at is exactly the same as mine, but...... Mine had a lable over the switch and 2 x 110v primary windings connected in series to make it a 220v unit.If the circuit specialists one was built in the same way, you could easily mod it.You could email them and ask - they may know.Kind RegardsSteve

author: picitup
author_rank: Regular Contributor
timestamp: October 25, 2015, 10:27:30 am
content: Hi again ErikIf you decide to buy a 110v version, I'd be happy to pop the case off mine and tell you how it's wired for 220v.CheersSteve

author: ErikTheNorwegian
author_rank: Frequent Contributor
timestamp: October 26, 2015, 12:56:13 am
content: Hi Steve!Thank you for a quick replay! Sorry for my bad engelish!I see Circuit Specialists on their website in the us said that they sold the powersupplay under their own names, as they are not a Hantek product. So their may different from those. I maild Circuit Specialists on friday, and hope to get a answerd on mandag regarding if it got two 110V taps on the trafo . If so, its a easy job to rewire it to 220. I presum you live in the UK?I was thinking to buy a Rigol, but the PPS2320A is such a good offer pricevice that its hard to beat. Got plenty of old pc's to hook up to it for programing. Im now only gone use it to smaler hobby projects, since im retierd. (At age 53!).I will update this tread as progres in getting it to Norway and how it goes with converting it to 220V.Cheers!Erik

author: picitup
author_rank: Regular Contributor
timestamp: October 30, 2015, 02:42:35 pm
content: Hi ErikI have mine apart at the moment so I've taken a few pics which I hope will help. Mine does have 2x 110v mains tappings and they are just hard wired in series. The wires are long enough to reach the switch cutout too. There's also a cutout for the voltage selector switch which is covered by a sticker on the back.Watch out for that metal plate on the back of the power connector as it's live! Make sure you pull the power cord out before working on it.Yes I live in the UK. I'm jealous you've retired at 53 as I'm 56 and still working lol. Hope to retire before 80 lol.I've got another thread going as the supply has a USB/serial device but I'm hoping to fit a native RS232 port to it.I got slated a little in my review as mine was faulty when it arrived and I had to fix it. I didn't mind though as I got a £70.00 refund and think it's impossible to get this kind of functionality for the price.Best of luck with your purchase.Steve

author: ErikTheNorwegian
author_rank: Frequent Contributor
timestamp: October 31, 2015, 11:56:08 am
content: Thank you Steve !I just realised that is was you who was working on the serial port to!Im thinking about looking into the software to add the posebilety of showing the Watt in realtime in the software control program for PC.Should be a easy task to add.. But need to get the supplay here and test it out first. Circuit Spesialst has a strange way of sending it, first i got a confirmation that it was sendt to me to a adress in the US, at a airport...They dont do it the cheapest way, so its adding to the cost. Bought sevral times from the UK office, and been very satisfied with the support, but sadly cant say the same for the US office. They dont give straight answersI will get mine in next week, so looking forward to that. Have you tried a USB to serial coverter on it? I have some BlackBoxs units that have worked well on other instruments.RegardsErik

author: picitup
author_rank: Regular Contributor
timestamp: October 31, 2015, 05:26:00 pm
content: Hi ErikNo probs glad to help. As I had it open, it only took 2 mins to take the photos :-)Well, if you can get the volts and current then the watts shouldn't be too hard :-)I don't buy much from the US as often the postage is half the cost of the unit and then we get stung for import duties and often the courier pays these and then claims them back from you + admin charge by which time my hair's fallen out.I haven't tried a PC/Serial connection yet as Kleinstein helpfully pointed out that in order to preserve the output isolation, I'm missing an isolated power supply. For the USB/Serial port on the PSU it's not a problem as the CP2102 simply uses the USB power from the PC so I've ordered some 5v-5v DC-DC converters. A guy in eBay was selling new old stock and I paid £8.00 for 4. Bargain.I'm guessing the distributors aren't too keen to open the units and may not even have the technical skills needed to answer your questions.Tomorrow I think I'm going to temporarily ignore the isolation issue and wire up a MAX3232 to it and see if it works. Probably could have done that before ordering the DC-DC converters but I never was that patient :-)ps You apologised for your English in a previous post. There's no need to as I can understand you perfectly and it's an order of magnitude better than my Norwegian lol. If the English are in a foreign country and can't be understood they just SPEAK LOUDER lol.It's loads of fun waiting for goodies in the post isn't it?CheersSteve

author: ErikTheNorwegian
author_rank: Frequent Contributor
timestamp: October 31, 2015, 11:27:04 pm
content: Quote from: picitup on October 31, 2015, 05:26:00 pmHi SteveUPS traking confirm delivery on wedensday 4.11.15, so not to long time to wait. Do think i will try out on my variac before i open it and do the coversion to 220V (We actualy got around 235-238 Volt here!)I think the price for it is a good one, since buying it from china is even more expencive!And my experience with Circuit Specialist UK (EU) has been very good, bought a BlackJack soldering station that is also a bargain.http://www.circuitspecialists.eu/bk-6000-blackjack-solderwerks-deluxe-rework-soldering-station/They had earlier the Hantek powersupplay, and i was about to order it, when they was sold out.Im will check it for overshoot when turned on off, since i work on some very delicate circuitry.(Underwater test gear for a oil company)Erik

author: ErikTheNorwegian
author_rank: Frequent Contributor
timestamp: November 13, 2015, 11:20:29 pm
content: Hi Steve,finaly i got the powersupplay, after some rude messages from the tracking/transport company that they where out on delivery, but it turned out that they where just changeing fraight company. So i stayed home twice , for to days just the discover that they just deliverd the powersupplay to a new fraight comapany.Ebays Global shipping program is a BIG joke!Well, the powersupplay come in one pice, and i tested it on 110V before rewiering the trafos senter tapp.Its not showing correct voltage, so a need to calibrate it.Use of the powersupplay, is excatley as one would excpect, making this to a joy to use. The software has some buggs, at least under W10, but im going to conect it to a XP machine that also runs Fluke, LeCroy, camera and other systems on the bench.well more tommorow...Erik..

author: picitup
author_rank: Regular Contributor
timestamp: November 14, 2015, 08:48:08 am
content: Hi ErikDon't start me off on Couriers lol. A couple of weeks ago I drove past a courier van and the guy was in the back of the van. To get from the back to the front, he walked over all the parcels. Amazing! It's irritating to wait in for a courier and they don't turn up.I'm pleased you have your supply and that it's in good working order so you don't need to fix itI've been pretty busy so haven't managed to progress the native RS232 port, but I'll try and get some time today and report back.Have fun....Steve