EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: Zero999 on July 26, 2015, 07:16:35 pm
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In the other thread, a discussion started about running DSOs off DC.
https://www.eevblog.com/forum/testgear/why-so-many-4-channel-scopes-dont-have-an-ext-trigger/msg717331/#msg717331 (https://www.eevblog.com/forum/testgear/why-so-many-4-channel-scopes-dont-have-an-ext-trigger/msg717331/#msg717331)
Anyone else tried running their oscilloscope off DC?
I've tested my Rigol DS1054Z and it works down to 36VDC before it starts rebooting and becoming unstable. This makes it suitable for operation off 48V. I've hooked it up to four SLAs connected in series and it works very well but it'd be nice to have a less bulky solution.
Any recommendations?
I haven't measured the current yet as my decent meter is at work.
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I have thought of this a few times with my DS1052E and after reading the post you referenced I am going to run to my shop and check on what voltage they will run.
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I find this hard to believe that anything inside of that scope requires anything higher than 12VDC. Are you feeding the 36VDC through the AC cord? If so, that would make sense. Although the power supply is probably a switching power supply. And while I am no expert on switching power supplies, I am thinking they will work on DC as well. But I am not sure if that would be a good idea or not. Maybe others would know.
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Careful with some SMPS chips that do not have UVLO in that they can go to 100% on time on the power switching device, which will blow it up along with the input diodes. As well careful of input active PFC that might do the same.
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I find this hard to believe that anything inside of that scope requires anything higher than 12VDC. Are you feeding the 36VDC through the AC cord? If so, that would make sense.
Yes, I just connected the power cord straight to the batteries.
Although the power supply is probably a switching power supply. And while I am no expert on switching power supplies, I am thinking they will work on DC as well. But I am not sure if that would be a good idea or not. Maybe others would know.
Yes, a switch mode power supply will work off DC. The mains is converted to DC with a bridge rectifier and smoothing capacitor so applying DC to the power cord will just give the same DC voltage on the smoothing capacitor, minus the rectifier losses which will be under 2V.
Having a switch mode power supply which is capable of running off such low DC voltages will mean a smaller smoothing capacitor can be used, which will make it cheaper.
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Well the DS1052E will not even start on 95VDC. That is not worth pursuing.
The DS1054Z will start with as little as 38VDC in my case. It starts more reliably with 40VDC. With 40VDC it draws around 600mA, 48VDC 450mA, and at 60VDC around 350mA. At 90VDC, which is not very practical for batteries, the current draw is more like 210mA.
I am not sure about the issue that SeanB raised in regards to the the SMPS chip overheating or dying, but I think that 48VDC or more might be a good voltage to aim for. Of course lithium battery technology would be better but a bit harder to manage charging with multiple cells.
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I find this hard to believe that anything inside of that scope requires anything higher than 12VDC.
LCD display CCFL tubes normally require 1KV +
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True for CCFL tubes, but does anybody use them anymore? Nowadays it is usually LEDs for back lighting. But for CCFL tubes, the power supply doesn't create that high voltage I don't think. It is usually a separate circuit commonly called an inverter. At least that is how it works on portable computers.
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True for CCFL tubes, but does anybody use them anymore?
AFAIK all currently available DSO's.
But for CCFL tubes, the power supply doesn't create that high voltage I don't think. It is usually a separate circuit commonly called an inverter.
Yes, normally derived from and on the PSU board.
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Wow I didn't know they were still in DSOs. Nor did I know they create the high voltage in the supply. That isn't how they do either in portable computers nowadays.
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I've tested my Rigol DS1054Z and it works down to 36VDC before it starts rebooting and becoming unstable. This makes it suitable for operation off 48V. I've hooked it up to four SLAs connected in series and it works very well but it'd be nice to have a less bulky solution.
Any recommendations?
how about a two SLAs and couple of boost converters?
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I am not sure what would be best yet. perhaps a 12V gel cell with a DC-DC converter, or a 48VDC set of gel cell batteries, or lithium cells with the same options.
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Why not an automotive booster pack with 120v output? Many have a 100w inverter on board and are gel cell based.
http://www.canadiantire.ca/en/pdp/eliminator-600a-400w-power-box-0112016p.html#.VbWzafm6Kpo (http://www.canadiantire.ca/en/pdp/eliminator-600a-400w-power-box-0112016p.html#.VbWzafm6Kpo)
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Well yes that works. I have done it with many different pieces of equipment. It is very inconvenient and bulky. I think the idea is something simple and relatively compact and light. I would like something that could be attached with velcro to the back, or something like that.
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Well yes that works. I have done it with many different pieces of equipment. It is very inconvenient and bulky. I think the idea is something simple and relatively compact and light. I would like something that could be attached with velcro to the back, or something like that.
Then just rig up a 100 watt inverter and a battery (cig lighter type). A switch to disconnect the inverter and connect to the charging rig to the batts. A flat gel cell will work but batt life is going to suck. I would use 2 cells in a box under the scope, not sure how you would attach it though. Be nice to have a batt indicator as well. Sticking to automotive voltages is handy because you can keep it charged on the fly. I'm not sure if there is a suitable pack (non LA) maybe in the rc car market? I trying to think cheap.
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Maybe make your own small, lightweight 90V lithium pack using these: http://www.ebay.com/itm/EBL-Lot-of-10-Pack-6F22-9V-600mAh-Rechargeable-Lithium-Ion-9-volt-Batteries-/371393371303?pt=LH_DefaultDomain_0&hash=item5678c51ca7 (http://www.ebay.com/itm/EBL-Lot-of-10-Pack-6F22-9V-600mAh-Rechargeable-Lithium-Ion-9-volt-Batteries-/371393371303?pt=LH_DefaultDomain_0&hash=item5678c51ca7)
(The ebay seller has lots of these and chargers for them too.)
According to your measurements, you should be able to get almost 3 hours of 'scope time using them.
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That's an idea, but I am afraid very impractical. It would be extremely tedious to manage and recharge 10 batteries. I have many other things to do before I can consider designing something like this.
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DC supply....no Line trigger. |O
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I don't think losing line trigger is much of a loss for total portability. You probably don't need it for those situations anyway.
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I am not sure what would be best yet. perhaps a 12V gel cell with a DC-DC converter, or a 48VDC set of gel cell batteries, or lithium cells with the same options.
2 small SLA and 2 DC boost converters. cheap, simple, easy.
http://smile.amazon.com/Powersonic-PS-1228-Rechargeable-Lead-Battery/dp/B000XB25HC/ (http://smile.amazon.com/Powersonic-PS-1228-Rechargeable-Lead-Battery/dp/B000XB25HC/)
http://smile.amazon.com/DROK-Transformer-Controller-Stabilizer-Automotive/dp/B00LJXGHC2/ (http://smile.amazon.com/DROK-Transformer-Controller-Stabilizer-Automotive/dp/B00LJXGHC2/)
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Actually I was thinking of something more like this:
http://www.ebay.com/itm/1-pcs-12V-1300mAh-Ni-MH-Rechargeable-Battery-Pack-K2-/131169079671?pt=LH_DefaultDomain_2&hash=item1e8a495177 (http://www.ebay.com/itm/1-pcs-12V-1300mAh-Ni-MH-Rechargeable-Battery-Pack-K2-/131169079671?pt=LH_DefaultDomain_2&hash=item1e8a495177)
Four or five in series would work for an hour or two.
Or maybe these:
http://www.ebay.com/itm/12V-3000mAh-Lithium-ion-Rechargeable-Battery-Pack-AC-DC-Charger-Adapter-Plug-/161460019982?hash=item2597c4630e (http://www.ebay.com/itm/12V-3000mAh-Lithium-ion-Rechargeable-Battery-Pack-AC-DC-Charger-Adapter-Plug-/161460019982?hash=item2597c4630e)
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I've seen ones like these before, used in security systems. The power connector is what stood out.
http://www.ebay.com/itm/12V-3000mAh-Lithium-ion-Rechargeable-Battery-Pack-AC-DC-Charger-Adapter-Plug-/161460019982?hash=item2597c4630e (http://www.ebay.com/itm/12V-3000mAh-Lithium-ion-Rechargeable-Battery-Pack-AC-DC-Charger-Adapter-Plug-/161460019982?hash=item2597c4630e)
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How about something like this?
(http://i.imgur.com/vj34jFk.jpg?1)
Designed for use in RC helicopters and apparently (http://www.alibaba.com/product-detail/44-4V-12S-4500mAh-50C-high_459540507.html) available from around $60-$90. Weight is around 1500g.
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you'll meed special multicell battery management systems for those complex RC batteries.
been down this road before. you don't want to deal with more than 2 cells if you can help it.
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Maybe a small 48 volt li-ion power pack and charger something like this:
http://www.amazon.com/Toro-88507-Standard-Charger-Lithium-Ion/dp/B00H2JQ50Q/ref=sr_1_2?ie=UTF8&qid=1438018948&sr=8-2&keywords=Toro+88508 (http://www.amazon.com/Toro-88507-Standard-Charger-Lithium-Ion/dp/B00H2JQ50Q/ref=sr_1_2?ie=UTF8&qid=1438018948&sr=8-2&keywords=Toro+88508)
and
http://www.amazon.com/Toro-88508-Standard-Lithium-Ion-Battery/dp/B00H2JQ4WA/ref=sr_1_1?ie=UTF8&qid=1438018948&sr=8-1&keywords=Toro+88508 (http://www.amazon.com/Toro-88508-Standard-Lithium-Ion-Battery/dp/B00H2JQ4WA/ref=sr_1_1?ie=UTF8&qid=1438018948&sr=8-1&keywords=Toro+88508)
All you need to do then is figure out how to connect to the power terminals.
Better still, just buy the whole trimmer (battery and changer included) and tear it down to get at the battery compartment. http://www.amazon.com/Toro-51488-48-Volt-Cordless-Trimmer/dp/B00H2JQ4WK/ref=sr_1_2?ie=UTF8&qid=1438019132&sr=8-2&keywords=toro+trimmer+48+volts (http://www.amazon.com/Toro-51488-48-Volt-Cordless-Trimmer/dp/B00H2JQ4WK/ref=sr_1_2?ie=UTF8&qid=1438019132&sr=8-2&keywords=toro+trimmer+48+volts)
You'll end up with a powerful 48 volt motor too! Kind of an expensive way to go, but easy.
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You'll end up with a powerful 48 volt motor too! Kind of an expensive way to go, but easy.
$180 vs $61. yeah, expensive... :)
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What type of battery do commercial battery powered scopes use? Would the battery pack from a Tektronix scope or even something like an Owon be of any use?
McBryce.
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I am beginning to think the NiMH batteries I linked to would be the best bet. The next question is if the SMPS controller chip is up to the task of continuous low voltage input.
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Some interesting suggestions.
I've measured the current and at 50V it's about 440mA, which agrees with Lightages's result, so I didn't bother measuring the current at different voltages.
I'd rather not use an inverter, not only does it take up extra space and use more power but cheap and lightweight inverters tend to be modified sinewave which are noisy and may cause problems with EMI.
A boost converter is better but it's still an additional loss of efficiency/battery capacity.
I prefer the idea of a passive solution. Each battery could be wired to separate contacts on a connector. When the 'scope connector is plugged in, the batteries could be wired in series and when the charger is connected, they could be wired in parallel or individually connected to separate chargers.
It's probably not a good idea to run the 'scope below 40V for long periods of time. I've ran it for awhile on 48V and nothing bad seemed to happen. The oscilloscope didn't run any hotter than normal.
My current set up uses four SLAs, I don't know what capacity but each weigh 2.5kg (so that's 10kg in total). The idea is to replace them with something lighter.
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Another potential issue running mains SMPS's on DC is if there is a real on-odd switch - DC ratings of switches are typically much lower due to potentially non self-extingguishing arc issues.
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how about bypassing the smps entirely? does the rigol really use 48v internally?
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Unfortunately nobody has done the reverse engineering to make a schematic yet. I haven't poked around inside yet neither. 48V is not any specification, it is just the lower reliable voltage that the power supply will start with.
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One thing I've noticed is there's less mains pick-up when run off a battery. On battery power, I can hold the probe in my hand and I get less than 2V peak to peak but on mains I get ten times that.
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So how are you coming along with this? If I were going to do it, I would opt for 18650 or even 26500 lithium batteries. Although you would need like 12 of them to connect in series to get the voltage you would want. You can buy battery holders, but I never seen one that holds like 12+ or them. Although you could connect smaller ones in series to hold more of course.
You know I too thought of doing the same with my GW Instek GDS-1062A. Although I later decided to opt for a UT81B (a portable scope that runs on four AA batteries instead). Not as good as yours or my other scopes. But it is portable, small, and easy on batteries. I get about 12+ hours straight on my Panasonic Eneloop 1900mah batteries per charge. The average drain is about 125ma @ 6v.
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The plan is to use four 12V batteries (regardless of the chemistry) and wire them to connectors. This should avoid the need for a specialised custom charger as 12V is a fairly common voltage.
I'll probably use two separate connectors, one for the anodes (socket) and one for the cathodes (plug), which will be made to be incompatible with one another to prevent short circuits. The idea is to change the configuration between series and parallel by wiring the connectors on the charger and oscilloscope differently.
I haven't decided what chemistry to use. For now, I'll just stick with the SLAs I have, make the connectors and cables, then I can look into buying some lightweight, higher energy density batteries.
(https://www.eevblog.com/forum/testgear/battery-pack-for-rigol-ds1054z/?action=dlattach;attach=163577;image)
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The idea is to change the configuration between series and parallel by wiring the connectors on the charger and oscilloscope differently.
Great idea. Ease of use without losing the ability to balance the batteries.
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still recommend against using >2 batteries. what a pain to constantly manage a pile of them.
dc boost converters cost almost nothing these days.
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I agree about the battery management being a pain but there are other considerations, such as forma factor and weight. It is easy to get four smaller batteries into a nice flat package to velcro to the back of the case than it is to get a big 12V higher capacity battery that will fit nicely. The 12V one battery has the benefit of being able to use a commonly available external DC source to run the scope too, like a car.
The question still remains if the SMPS IC inside is being over stressed by running at 48V nominal.
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bypass the internal ps and find out what real voltage it consumes internally. unlikely it is 48vdc. drill a hole and put a barrel connector.
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There are probably more like 3.3V, 5V, -5V, 9V,12V -12V and maybe more. A simple internal direct DC feed is not going to work.
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There are probably more like 3.3V, 5V, -5V, 9V,12V -12V and maybe more. A simple internal direct DC feed is not going to work.
Pretty sure you could check this from Dave's teardown - at the very least establish how many rails there are. you'd need to pull it apart to measure current though.
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from the teardown: 6.3V -7.5V 5V5A -17.5V
internal psu header similar to atx. potential market for someone to make a simple retrofit board for 12v battery powered rigol. similar to this: http://www.amazon.com/Mini-PicoPSU-150-XT-DC-DC-power-supply/dp/B0045WFZSQ (http://www.amazon.com/Mini-PicoPSU-150-XT-DC-DC-power-supply/dp/B0045WFZSQ)
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bypass the internal ps and find out what real voltage it consumes internally. unlikely it is 48vdc. drill a hole and put a barrel connector.
:-DD
And what supplies the LCD backlight?
Not DC.
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Actually, from Dave's tear down photos, 5V at 5A x2, 6.3V x2, -7.5V, 17.5V, -17.5, plus fan supply. As Dave said in his video it would possible to replace the entire power supply with a fully redesigned one with an internal battery. I agree this would be optimal but not cheap. The OP's idea, I believe, is something simple and easy and external so as to not have to hack or replace major components. Four 12V battery packs in series can be done for around $40 plus a charger. Make that $60 for a hack and it is ready to go. Redesign a complete power supply and stuff it inside is going to be a longer process and probably not cheap. Perhaps there is a Kickstarter opportunity for someone here. With enough volume it could be cheaper in the long run than a DIY quick hack. The problem is that it would be mains powered device and need all the relevant certifications. Designing a power supply and battery to stuff inside is not going to be cheaper I would think, if only for a one off or even tens.
Perhaps the idea of a plug in DC-DC converter running from 12V is a good idea. This would circumvent the need for safety certifications and people could use a certified generic power brick for AC use and an external battery for portable use. The problem with this then becomes the loss of AC sync, and hacking the cabinet.
Still, four 12V batteries in series would be the fastest and simplest way at this point. In Dave's tear down I did not see what SMPS chip is being used, but I could be blind or too impatient to watch all of it again.
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Actually, from Dave's tear down photos, 5V at 5A x2, 6.3V x2, -7.5V, 17.5V, -17.5, plus fan supply. As Dave said in his video it would possible to replace the entire power supply with a fully redesigned one with an internal battery. I agree this would be optimal but not cheap. The OP's idea, I believe, is something simple and easy and external so as to not have to hack or replace major components. Four 12V battery packs in series can be done for around $40 plus a charger. Make that $60 for a hack and it is ready to go. Redesign a complete power supply and stuff it inside is going to be a longer process and probably not cheap. Perhaps there is a Kickstarter opportunity for someone here. With enough volume it could be cheaper in the long run than a DIY quick hack. The problem is that it would be mains powered device and need all the relevant certifications. Designing a power supply and battery to stuff inside is not going to be cheaper I would think, if only for a one off or even tens.
Perhaps the idea of a plug in DC-DC converter running from 12V is a good idea. This would circumvent the need for safety certifications and people could use a certified generic power brick for AC use and an external battery for portable use. The problem with this then becomes the loss of AC sync, and hacking the cabinet.
Still, four 12V batteries in series would be the fastest and simplest way at this point. In Dave's tear down I did not see what SMPS chip is being used, but I could be blind or too impatient to watch all of it again.
Couldn't you just check the Service manual for the PSU voltages? :-//
Does it not come with these scopes on the CD along with the User manual?
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Actually, from Dave's tear down photos, 5V at 5A x2, 6.3V x2, -7.5V, 17.5V, -17.5, plus fan supply. As Dave said in his video it would possible to replace the entire power supply with a fully redesigned one with an internal battery. I agree this would be optimal but not cheap. The OP's idea, I believe, is something simple and easy and external so as to not have to hack or replace major components. Four 12V battery packs in series can be done for around $40 plus a charger. Make that $60 for a hack and it is ready to go. Redesign a complete power supply and stuff it inside is going to be a longer process and probably not cheap. Perhaps there is a Kickstarter opportunity for someone here. With enough volume it could be cheaper in the long run than a DIY quick hack. The problem is that it would be mains powered device and need all the relevant certifications. Designing a power supply and battery to stuff inside is not going to be cheaper I would think, if only for a one off or even tens.
Perhaps the idea of a plug in DC-DC converter running from 12V is a good idea. This would circumvent the need for safety certifications and people could use a certified generic power brick for AC use and an external battery for portable use. The problem with this then becomes the loss of AC sync, and hacking the cabinet.
Still, four 12V batteries in series would be the fastest and simplest way at this point. In Dave's tear down I did not see what SMPS chip is being used, but I could be blind or too impatient to watch all of it again.
Couldn't you just check the Service manual for the PSU voltages? :-//
Does it not come with these scopes on the CD along with the User manual?
That would be a no. I'm not sure I have ever seen a Rigol service manual or schematic.
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Actually, from Dave's tear down photos, 5V at 5A x2, 6.3V x2, -7.5V, 17.5V, -17.5, plus fan supply. As Dave said in his video it would possible to replace the entire power supply with a fully redesigned one with an internal battery. I agree this would be optimal but not cheap. The OP's idea, I believe, is something simple and easy and external so as to not have to hack or replace major components. Four 12V battery packs in series can be done for around $40 plus a charger. Make that $60 for a hack and it is ready to go. Redesign a complete power supply and stuff it inside is going to be a longer process and probably not cheap. Perhaps there is a Kickstarter opportunity for someone here. With enough volume it could be cheaper in the long run than a DIY quick hack. The problem is that it would be mains powered device and need all the relevant certifications. Designing a power supply and battery to stuff inside is not going to be cheaper I would think, if only for a one off or even tens.
Perhaps the idea of a plug in DC-DC converter running from 12V is a good idea. This would circumvent the need for safety certifications and people could use a certified generic power brick for AC use and an external battery for portable use. The problem with this then becomes the loss of AC sync, and hacking the cabinet.
Still, four 12V batteries in series would be the fastest and simplest way at this point. In Dave's tear down I did not see what SMPS chip is being used, but I could be blind or too impatient to watch all of it again.
Couldn't you just check the Service manual for the PSU voltages? :-//
Does it not come with these scopes on the CD along with the User manual?
That would be a no. I'm not sure I have ever seen a Rigol service manual or schematic.
:o
http://www.siglentamerica.com/support_download_11 (http://www.siglentamerica.com/support_download_11)
What isn't there is currently being prepared for free download access.
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Actually, from Dave's tear down photos, 5V at 5A x2, 6.3V x2, -7.5V, 17.5V, -17.5, plus fan supply. As Dave said in his video it would possible to replace the entire power supply with a fully redesigned one with an internal battery. I agree this would be optimal but not cheap. The OP's idea, I believe, is something simple and easy and external so as to not have to hack or replace major components. Four 12V battery packs in series can be done for around $40 plus a charger. Make that $60 for a hack and it is ready to go. Redesign a complete power supply and stuff it inside is going to be a longer process and probably not cheap. Perhaps there is a Kickstarter opportunity for someone here. With enough volume it could be cheaper in the long run than a DIY quick hack. The problem is that it would be mains powered device and need all the relevant certifications. Designing a power supply and battery to stuff inside is not going to be cheaper I would think, if only for a one off or even tens.
Perhaps the idea of a plug in DC-DC converter running from 12V is a good idea. This would circumvent the need for safety certifications and people could use a certified generic power brick for AC use and an external battery for portable use. The problem with this then becomes the loss of AC sync, and hacking the cabinet.
Still, four 12V batteries in series would be the fastest and simplest way at this point. In Dave's tear down I did not see what SMPS chip is being used, but I could be blind or too impatient to watch all of it again.
Couldn't you just check the Service manual for the PSU voltages? :-//
Does it not come with these scopes on the CD along with the User manual?
That would be a no. I'm not sure I have ever seen a Rigol service manual or schematic.
:o
http://www.siglentamerica.com/support_download_11 (http://www.siglentamerica.com/support_download_11)
What isn't there is currently being prepared for free download access.
@ tautech that really deserves a thread of it's own and Siglent should push that info.
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bypass the internal ps and find out what real voltage it consumes internally. unlikely it is 48vdc. drill a hole and put a barrel connector.
:-DD
And what supplies the LCD backlight?
Not DC.
I have never seen a CCFL backlight that's run from a main PSU board in anything other than a TV or monitor - there is always a separate inverter running off one of the DC supplies, most commonly 12V.
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While I agree that Siglent is much more up front with information, I would not call the service manual from Siglent a real service manual. There is a lot of useful information, but no schematics and no parts list. There is not even a block diagram. Like I said, much better than Rigol.
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bypass the internal ps and find out what real voltage it consumes internally. unlikely it is 48vdc. drill a hole and put a barrel connector.
:-DD
And what supplies the LCD backlight?
Not DC.
not DC? how the heck do you think laptops work? AC batteries maybe? :-DD
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bypass the internal ps and find out what real voltage it consumes internally. unlikely it is 48vdc. drill a hole and put a barrel connector.
:-DD
And what supplies the LCD backlight?
Not DC.
I have never seen a CCFL backlight that's run from a main PSU board in anything other than a TV or monitor - there is always a separate inverter running off one of the DC supplies, most commonly 12V.
Inside DSO's where space is at a premium, it's not uncommon. Sure the backlight supply is derived from DC, and from/on the main PSU PCB.
Tek TDS2000 series used this format too.
usagi implied the DSO could be powered from a single DC supply, this I doubt very much. :-//
I would not call the service manual from Siglent a real service manual. There is a lot of useful information, but no schematics and no parts list.
You can do a board level fault diagnosis with this info though.
Which manufacturers supply a full schematic with equipment these days?
Parts lists hopefully will soon be available, it's something I've asked for and Jade has said they're in translation. ;)
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It's actually a little surprising that there isn't a 1054z schematic, hand made of course. Dave did a bit on the front end and there is certainly enough interest.
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I've just done a bit of experimenting with this (http://www.ebay.co.uk/itm/Adjustable-DC-3-35V-to-3-5-35V-5-12V-Boost-Converter-Voltage-Regulator-Voltmeter-/371242209860?hash=item566fc29244:g:Y-gAAOSwpDdVGSEg) set for 12Vout and this (http://www.ebay.co.uk/itm/600W-Boost-Converter-DC-DC-Step-Up-Module-Power-Supply-High-Voltage-Regulator-/381396068107?hash=item58ccfa270b:g:qmcAAOSwWnFV8VJT) set for 60Vout and a battery pack of 8 x NiMH rechargeables (2500mAH) to power it all. It works! It is possible to power up and run the Rigol DS1054Z on AA batteries :D
No use to me at the moment so I won't be doing any more, but it is possible.
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I've just done a bit of experimenting with this (http://www.ebay.co.uk/itm/Adjustable-DC-3-35V-to-3-5-35V-5-12V-Boost-Converter-Voltage-Regulator-Voltmeter-/371242209860?hash=item566fc29244:g:Y-gAAOSwpDdVGSEg) set for 12Vout and this (http://www.ebay.co.uk/itm/600W-Boost-Converter-DC-DC-Step-Up-Module-Power-Supply-High-Voltage-Regulator-/381396068107?hash=item58ccfa270b:g:qmcAAOSwWnFV8VJT) set for 60Vout
You mean two boosters in series, one feeding the other?
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Yes, in series. For a more permanent solution I'd recommend a SLA and just the second booster from12 to 60V, cheap as chips and it stays cool.
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It would be cool, if you can cram this into the original internal PSU space, and make an external charging connector available.
This way you would have the world's cheapest usable portable oscilloscope (counting out Owon).
Unfortunately the 4 channels are not fully isolated from each other (common negative reference).
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most of us have a favorite cordless tool set and most of them are 18 -20 volt why not use these batteries
It would be easy to cobble up a plug in banking circuit. you then have about say 60 volts with three batteries spare batteries easily available and chargers already on hand.
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how the heck do you think laptops work? AC batteries maybe?
What I would like to know, would the Batterizer work on AC batteries? If so maybe they could be used for this project.
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Just checked Indigogo and even the nuts there haven't "invented" an AC battery yet. Maybe we should start a campaign, but it would need to have a 50/60Hz switch so that it works in all regions! :-DD
McBryce.
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It need a knob that goes from DC to 400 hz For those obsolete 25 HZ systems and for aircraft
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So... are there any updates on powering it with (>40V) DC through the internal PSU?
Edit:
Any ideas how to get the Math function to calculate current? Got R=7,29Ohm (so no even 10-base..) but there is no option to calculate A/B with anything but the Channels as the two inputs...? Why is there no option for a fixed value? :-//
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CORRECTION, April 7:
The mA reading from the analogue meter is wrong. The actual reading with a better meter is between 470 and 500 mA. I posted more information in another post below.
I just finished building a 48 Volt 2.4 AH battery back for my new DS1054Z.
The pack consists of 12 18650 Lithium batteries in series. I built a holder using 18650 battery holders from eBay.
The battery holders were hot glued to a 5mm piece of plywood and mounting tabs were also glued to the base. The battery holders provide slots for ribbon to help remove the batteries. The batteries are near impossible to remove without the ribbon and are susceptible to damage using tools like a screwdriver.
There is no way to charge the whole pack at once. It will take three salvos in my four slot battery charger to do the job. Not a problem for me because I do not expect daily use on battery power. I will use it for trouble shooting CNC equipment and would like to have the scope isolated from Mains Power.
The batteries are 2400mAh as measured on my battery charger. They are labeled as 4200 mAh :palm: but they are about $20USD for 12. They are also labeled as "Protected" for what that may be worth. I would like to fuse protect the pack just in case.
I am using modified (screwdriver and hammer) female spade lug connectors to attach to the mains input. They are not bump proof so will look for a cord to scavenge for a proper connector.
Here are the power stats: Current draw from the battery pack is 225 mA at 48 volts. Thats only 11 Watts.
During boot up it drew only 190 mA. I will probably never run this more than 2 hours at a time with the batteries.
So the concept works. This blog was the final factor that sold me on this scope as I was also considering a hand held for Mains isolation but those would not be optimal for other projects and courses I am working on. 48 Volts straight into the AC power input simple beautiful.
Photos are attached.
The original intent for mounting was to use heavy wire hooked around the handle hinge pins but found that it requires some drilling which I am not ready for at this point so am just using string for the time being. Please, no one suggest peel and stick Velcro because the Velcro is generally stronger than the glue which fails and makes a mess.
If anyone sees anything dangerous going on here please let me know. I have a great deal of respect for the energy density of these batteries.
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Where is your fuse ?
Also, I don't recall if the Rigol has a real mains switch - if so, it is probably not rated for DC operation, so there may be arcing issues.
You should probably also do a thermal test on the PSU, as the primary-side switch, and filter components may not be rated for the higher primary current operating on DC.
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Now you're feeding a continuous current (previously it was half wave) of about 3..4x more amps through just one half of the bridge rectifier, iow there are 2 diodes working 100% of the time doing ~6..8x more work than before and the other 2 diodes doing nothing. It all depends on the rating of that bridge so perhaps that's something worth investigating.
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Now you're feeding a continuous current (previously it was half wave) of about 3..4x more amps through just one half of the bridge rectifier, iow there are 2 diodes working 100% of the time doing ~6..8x more work than before and the other 2 diodes doing nothing. It all depends on the rating of that bridge so perhaps that's something worth investigating.
:-DMM I just checked AC current draw with a Kill O Watt meter. It is drawing 290mA on 118AC Volts. That is in the same ballpark if not more than the straight DC battery pack draw of 225mA. The KOW meter also indicates a whopping 36 Volt Amps but only 22Watts Power. Again, the calculated DC power draw is 11 Watts.
Watching Daves teardown video, starting at 11:15
https://youtu.be/kb9P1Am9aFU?list=PLvOlSehNtuHsy89OdSxBajult8e5srVLA
all the components look beefy enough to handle much larger currents and the bridge rectifier looks like it could handle 2 to 3 Amps or at least 500mA per diode. It all looks fairly simple with just step down, rectify and filter then regulate. Aside from the bridge rectifier, there are only 3 active components to deliver output voltages. But what are the opto couplers used for in a PSU? There is the circuit in the top left section of the Hot End; a diode coming off the first stage regulator, a filter cap then the opto couplers and a single transistor. Does this supply a reference voltage to the Cold end regulators?
When the batteries drop to 36 Volts, which is when the scope will shut down, the Amp draw will be 300mA.
After getting some facts, I am not worried at all about damaging the scope.
I am worried about burning my house down though with the battery pack.
My real concern is doing something unseen and stupid with the Lithium batteries that I am not aware of. Each battery is supposed to be current protected and I confirmed that once by accidentally inserting it in the battery charger backwards and it now no longer works. But I do not mind wearing suspenders and a belt when it involves the possibility of burning my house down.
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When it's plugged into 118Vac the capacitor after the bridge was at ~168V, now it's at ~48V about 3.5x times less volts ergo the current must be 3.5x more amps, and it's all going through the same 2 diodes always when before only half of the time (half a cycle). So 3.5x times higher current * twice the time.
Put it another way: 118V*0,25A is not = to 48V*0,25A, so something is wrong there because it draws the watts it draws (and that's a constant regardless of V).
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Where is your fuse ?
Also, I don't recall if the Rigol has a real mains switch - if so, it is probably not rated for DC operation, so there may be arcing issues.
You should probably also do a thermal test on the PSU, as the primary-side switch, and filter components may not be rated for the higher primary current operating on DC.
Dave's tear-down video of the ds1054z shows that it has a hardwired main power switch that throws the 120v. No soft switch.
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When it's plugged into 118Vac the capacitor after the bridge was at ~168V, now it's at ~48V about 3.5x times less volts ergo the current must be 3.5x more amps, and it's all going through the same 2 diodes always
I estim guestimate that when it's run from 118Vac the bridge conducts only about 1/5 of the time(1/10 of the time each pair of diodes), giving a peak of current and volt across each diode to keep the 160Vdc topped up.
I guestimate the average dissipation in each diode always less than 200mW, even when only 2 are being used with DC input.
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the bridge conducts only about 1/5 of the time
You're right, 100% right, my bad.
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After using this battery pack a few times and watching how many Amp hours it took to recharge, my current reading with the analogue meter did not make sense.
I found a cheap digital meter that would handle the current. My Fluke 16 only reads up to9.9 UA.
The bottom line is that it is using about 470 to 500 mA between 54 to 50 Volts input.
I am not going to worry about the rating on the switch or the bridge rectifier. The bridge rectifier looks beefy enough and both the bridge and switch should be cheap and easy to replace even if I have to use generics.
I get at least 2 hours run time off the battery which is more than I need for troubleshooting CNC equipment.
Recharging the batteries is a small bother but I am use 18650 batteries for everything I can and am building battery packs for other equipment that uses 9 volts and LED lights that use 3 AAA batteries.
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Here's my setup. Rigol runs just perfectly from four 18 V tool batteries. The background noise is nonexistent and makes real joy of scoping. I also have new Fluke Scopemeter but this time I needed clearer screenshots and better data.
Would I recommend this? Nope, if you are 200 pound gorilla like AvE says it. But at this job Rigol made the difference between solving problem or not. Mining industry is really hard on equipment and I was surprised how Rigol even survived. For future I'm real keen on waterproofing this scope. It's so much better than other handheld scopes we have.
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Wow, that's quite an environment for it. It'll be interesting to see how you go about waterproofing it.
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Wow, that's quite an environment for it. It'll be interesting to see how you go about waterproofing it.
Seal the fan opening ? :o :-DD
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Liquid cooling. :-+
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Anyone tried the Omnicharge (https://www.omnicharge.co/products/omni-20) and its HVDC output (US version 150V, EU 300V) to power the DS1054Z? I've powered several SMPSs with the 300V DC with no problems, but haven't dared risk the scope yet, since I don't know whether the rectifier diodes can handle a continuous high voltage for prolonged periods.
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Wow, that's quite an environment for it. It'll be interesting to see how you go about waterproofing it.
Seal the fan opening ? :o :-DD
https://www.youtube.com/watch?v=yAahT8_P-_E (https://www.youtube.com/watch?v=yAahT8_P-_E)
https://www.youtube.com/watch?v=VZCokbsTwmQ (https://www.youtube.com/watch?v=VZCokbsTwmQ)
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Liquid cooling. :-+
Now liquid cooling is not a bad option. Very small radiator inside case and circulate fan air somehow from side to side. The liquid could be 0W-40 motor oil and pump could be some tiny 24 V fuel pump. Why oil and not glycol water? Well, I just like to keep them separate if possible from 230 AC.
I seem to like 24 and 48 VDC stuff. Industrial legos are quite fun to do projects with. I thought that small heating pad from truck mirror could bring the machine always to normal operating temperature. Yeah I'm also thinking of possibly using this in freezing cold and getting rid of moisture.
For sealing the front I haven't yet figured any good solution. Maybe just pour thin silicone layer on top of everything. I already have dedicated pelican case for this and ready to be modded.
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Hi,
My DS1074Z got spoilt. I think it is the power supply.
Saw some light coming from the back, now it wont power up.
Do anyone of you got info on the voltages of the pins?
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Do anyone of you got info on the voltages of the pins?
sorry friend for being 3 years late. but late is still better than never right?... found this while searching for DS1052E PSU schematics. see attachments. to conclude.. rails needed for DS1054Z..
1) 9V
2) 5V
3) ±7.5V
4) ±17.5V
6 rails total...
Uncle Bob: "so what's our plan?"
Uncle Jack: "to make a plan."
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As variant
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I created a "3d printed clip" to power the DS1054Z with 3x 20V worx (power tools) batteries. Easy to swap and charge. Last about 4 hours with 1.5Ah batteries.
No circuit needed, batteries are plugged in series (60V total).
You can print your own or modify it to fit other brand batteries (not the type with the long neck... ex: Ryobi)
Check it here :)
https://www.thingiverse.com/thing:4744634 (https://www.thingiverse.com/thing:4744634)
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head up for my Battery Powered PSU for Portable Rigol DS1000E/Z (https://www.eevblog.com/forum/projects/battery-powered-psu-for-portable-rigol-ds1000ez) to thread followers, cheers.
That link gives me a 404 error.
McBryce.
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duh.. deleted and corrected.. thanks McBryce for highlighting... head up for my Battery Powered PSU for Portable Rigol DS1000E/Z (https://www.eevblog.com/forum/projects/battery-powered-psu-for-portable-rigol-ds1000ez/msg4000525/#msg4000525) to thread followers, cheers.
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have you a link to the vid from dave mentioned?
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I have a 48v battery on my homebrew e bike,does that mean if i connect my scope mains power cable to that it will work?.,or best hook it upto the mains filter cap,ie output side of the psu bridge rectifier?.
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I was going to suggest e-bike or hoverboard Li-ION packs could work.
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so long story short could i hook my scope upto my 48v ebike battery using the scopes mains cable and have it work without letting smoke out of it?,mine is a rigol DS1052D