Author Topic: Battery pack for Rigol DS1054Z (Read 43904 times)

Zero999 · « **on:** July 26, 2015, 07:16:35 pm »

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

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.

Lightages · « **Reply #1 on:** July 26, 2015, 07:22:33 pm »

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.

BillW50 · « **Reply #2 on:** July 26, 2015, 07:35:13 pm »

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.

SeanB · « **Reply #3 on:** July 26, 2015, 07:38:20 pm »

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.

Zero999 · « **Reply #4 on:** July 26, 2015, 07:43:03 pm »

Quote from: BillW50 on July 26, 2015, 07:35:13 pm

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.

Quote

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.

Lightages · « **Reply #5 on:** July 26, 2015, 08:02:52 pm »

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.

tautech · « **Reply #6 on:** July 26, 2015, 08:25:42 pm »

Quote from: BillW50 on July 26, 2015, 07:35:13 pm

I find this hard to believe that anything inside of that scope requires anything higher than 12VDC.

LCD display CCFL tubes normally require 1KV +

BillW50 · « **Reply #7 on:** July 26, 2015, 08:34:42 pm »

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.

tautech · « **Reply #8 on:** July 26, 2015, 08:43:07 pm »

Quote from: BillW50 on July 26, 2015, 08:34:42 pm

True for CCFL tubes, but does anybody use them anymore?

AFAIK all currently available DSO's.

Quote

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.

BillW50 · « **Reply #9 on:** July 26, 2015, 08:50:06 pm »

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.

usagi · « **Reply #10 on:** July 27, 2015, 02:13:37 am »

Quote from: Hero999 on July 26, 2015, 07:16:35 pm

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?

Lightages · « **Reply #11 on:** July 27, 2015, 03:22:08 am »

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.

pickle9000 · « **Reply #12 on:** July 27, 2015, 04:30:38 am »

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

Lightages · « **Reply #13 on:** July 27, 2015, 04:38:33 am »

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.

pickle9000 · « **Reply #14 on:** July 27, 2015, 04:57:54 am »

Quote from: Lightages on July 27, 2015, 04:38:33 am

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.

kwass · « **Reply #15 on:** July 27, 2015, 05:08:43 am »

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

(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.

Lightages · « **Reply #16 on:** July 27, 2015, 05:45:18 am »

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.

tautech · « **Reply #17 on:** July 27, 2015, 05:50:12 am »

DC supply....no Line trigger.

Lightages · « **Reply #18 on:** July 27, 2015, 05:54:32 am »

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.

usagi · « **Reply #19 on:** July 27, 2015, 06:34:26 am »

Quote from: Lightages on July 27, 2015, 03:22:08 am

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/DROK-Transformer-Controller-Stabilizer-Automotive/dp/B00LJXGHC2/

Lightages · « **Reply #20 on:** July 27, 2015, 06:51:40 am »

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

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

pickle9000 · « **Reply #21 on:** July 27, 2015, 08:01:12 am »

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

rolycat · « **Reply #22 on:** July 27, 2015, 08:59:05 am »

How about something like this?

Designed for use in RC helicopters and apparently available from around $60-$90. Weight is around 1500g.

usagi · « **Reply #23 on:** July 27, 2015, 09:13:23 am »

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.

kwass · « **Reply #24 on:** July 27, 2015, 05:49:06 pm »

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

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

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

You'll end up with a powerful 48 volt motor too! Kind of an expensive way to go, but easy.


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Author Topic: Battery pack for Rigol DS1054Z (Read 43904 times)

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