SOLD (UK) Assorted Tenma scopes - Page 1
Forum section: electronics / general

author: TopLoser
author_rank: Unknown
timestamp: November 12, 2016, 01:19:31 pm
content: http://uk.farnell.com/tenma/72-9355/oscilloscope-handheld-dso-2ch/dp/206182560MHz, 2 channel, 250MS/s hand held scope with integrated DMM.Unused in a nice metal case with 2 scope probes, DMM probes, current converters, strap, CD and manual.MISSING the mains charger but I'll include a shoddy lead so you can connect it to any 5V supply that can supply 1.5ABattery pack is DEAD, it's 4 18650 cells and it's been sat unused for over a year so they're incapable of taking a charge now.It's actually a very nice little scope, with a battery pack rebuild it'll be a useful thing.£150+VAT£125+VAT and shippinghttp://uk.farnell.com/tenma/72-10510/oscilloscope-2ch-25mhz-250msps/dp/228359325MHz, 2 channel, 250MS/s, 7" widescreen, USBBoxed, unused, customer return because the x1/10 switch on 1 probe was damaged. Fully working but missing one probe.£60+VAT and shippinghttp://uk.farnell.com/tenma/72-8705/oscilloscope-2ch-50mhz-1gsps/dp/183605950MHz, 2 channel, 1GS/s, 7" widescreen, USBBoxed, unused, customer return. Replaced mains fuse and it works fine. Includes 2 probes.£75+VAT and shippinghttp://uk.farnell.com/tenma/72-8710/oscilloscope-2ch-100mhz-1gsps/dp/1836060Boxed, unused, customer return because the x1/10 switch on 1 probe was damaged. Fully working but missing one probe.£95+VAT and shippingShipping UK £10, sensible EU countries £20. VAT invoice issued, only pay the VAT if it applies to you.ALL SOLD

author: WackyGerman
author_rank: Regular Contributor
timestamp: November 12, 2016, 01:36:10 pm
content: Nice bargain . Seems that the probes don t have a good quality . I would prefer to buy probes separately

author: SeanB
author_rank: Super Contributor
timestamp: November 12, 2016, 01:37:26 pm
content: How much to post to ZA Ian for the 25MHz or 50 MHz Tenmas?I have spare probes.....

author: TopLoser
author_rank: Unknown
timestamp: November 12, 2016, 01:41:42 pm
content: £25 with DPD to South Africa

author: SeanB
author_rank: Super Contributor
timestamp: November 12, 2016, 02:02:15 pm
content: PM sent. Do you still have those oddments you use as packaging material Ian, those were almost more interesting than the last lot.

author: TopLoser
author_rank: Unknown
timestamp: November 12, 2016, 02:05:58 pm
content: Yes Sean I'm sure I have some random crap to stuff in the spaces...

author: rt
author_rank: Regular Contributor
timestamp: November 12, 2016, 02:38:05 pm
content: PM Sent

author: SeanB
author_rank: Super Contributor
timestamp: November 12, 2016, 03:15:00 pm
content: Quote from: TopLoser on November 12, 2016, 02:05:58 pmFather Christmas delivers again! Only the top loss leader left here new.

author: TopLoser
author_rank: Unknown
timestamp: November 12, 2016, 03:20:22 pm
content: Last one reduced, I want a clear desk by the end of the day please...

author: bingo600
author_rank: Super Contributor
timestamp: November 17, 2016, 03:28:02 pm
content: IanI got the portable Tenma today , looking goodThnx (also for the power wire)/Bingo

author: SeanB
author_rank: Super Contributor
timestamp: November 17, 2016, 07:47:38 pm
content: Been chimping on the Interparcel track and it just ( hopefully) left the UK today, still do not know which local courier will be the one doing me over for duties though.....

author: TopLoser
author_rank: Unknown
timestamp: November 18, 2016, 11:23:43 am
content: Quote from: SeanB on November 17, 2016, 07:47:38 pm4-6 days they promised when they took £70 off me!

author: SeanB
author_rank: Super Contributor
timestamp: November 19, 2016, 08:09:26 am
content: Working days, so probably arriving at JNB customs today, then will sit there the weekend. Left Belgium ( hi there to all the Flemish watchers) yesterday, and probably is travelling cargo.

author: bingo600
author_rank: Super Contributor
timestamp: January 06, 2017, 08:06:02 pm
content: @IanTook some time to get the parts for my new battery , but not it's doneI initially bought some "China battery's" , but ended up bying and using some New "Tabbed SONY's"http://www.ebay.de/itm/281518637378When i "cut open the original pack" i saw the charger pcb , that needed to be transplanted too.Original Batt pics attached here.The config was 2 x Cells in parallel in bottom , and 2 x Cells in Parallel in the top.Those two blocks were in series , giving 7.4v out./Bingo

author: bingo600
author_rank: Super Contributor
timestamp: January 06, 2017, 08:18:29 pm
content: The DIY packIt began it's life in a "protected environment".I measured 8.3v on the Scope connector , so i started with that and 2A current.Followed it for a while , using "the 5-finger thermometer" , and no probs.Upped the charge current to 4A (PSU specs) , and followed it , no probs.Waited for the charge current to fall to approx 500mA , wrapped it in plastic & gaffer tape , and mounted it.Charged it in the Scope for 8 hr's ,and the scope now wrote "Full" besides the charge icon.Ohh: The green plastic protection on the cells are quite thinI found out the "spark way"When soldering the charge wire to plus on the PCB, the "plus pin went through" the protectionWell nothing happened besides the short fireworks, and me learning a lesson.That's why you see the foam pad below the pcb , on my diy version./Bingo

author: TopLoser
author_rank: Unknown
timestamp: January 06, 2017, 08:48:08 pm
content: Nice job, well the effort it seemed to be a capable little scope. Well done findimg a charger with that stupid long barrel connector as well!

author: SeanB
author_rank: Super Contributor
timestamp: January 06, 2017, 08:50:52 pm
content: Nice work on the new pack, I did a similar thing using some scrapped laptop battery packs. Like you probably found out the packs are not easy to open, but I got 8 sets of 2 cells out, though 6 sets were dead ( under 2V, some under 0.1V) so went into the scrap pile. The remaining 2 sets went into a cheap powerpack from eBay, upgrading it from 1S to 4S, though I do not think it will provide 1A as on the paper before blowing up, I think 0.5A will be fine though.

author: bingo600
author_rank: Super Contributor
timestamp: January 06, 2017, 08:53:04 pm
content: Quote from: TopLoser on January 06, 2017, 08:48:08 pmThe charger was already on the original batt pack.I just took it from the original , and transplanted it on the new pack.I should have kept the alu strips in both ends though, soldering a wire on the + end of the new batt pack , actually caused a bit of trouble when closing the chassis. As it became a few mm longer./BingoOhh:I actually think i could solder wires directly on the batteries wo. heating too much.My metcal was "flowing" applied 0.3mm solder on the "old" batteries in less than 4 sec.So if you have a decent iron, you might not need batteries with tabs.

author: Fraser
author_rank: Super Contributor
timestamp: January 06, 2017, 09:05:01 pm
content: Interesting thread. I own a couple of the UNI-T branded versions of the portable scope. It is interesting to see inside the battery pack as I received one scope without its battery (international shipping restrictions on Li-Ion batteries). I have purchased a replacement pack intended for radio control use. I doubt it has the little protection PCB in it so I had better add one 🙂

author: SeanB
author_rank: Super Contributor
timestamp: January 06, 2017, 09:08:06 pm
content: 99p including shipping on eBay Fraser, I added a few to another order, just in case I needed some.

author: bingo600
author_rank: Super Contributor
timestamp: January 06, 2017, 09:13:24 pm
content: Quote from: Fraser on January 06, 2017, 09:05:01 pmOhh yeaahh , else you'd give the pack 8.3v directly.If you're lucky you have no scope , unlucky ... No houseNote:There's not much extra room in the bat compartment, so see if you can get a "slim pcb like the one on the pics".The charger is actually connecting to the top (3.7v) pack , and then an additional black wire is going from the charger to the minus on the bottom pack.Maybe Sean or some other guru can tell what's going on there.Please don't ask me to cut my diy pack open again./Bingo

author: Fraser
author_rank: Super Contributor
timestamp: January 06, 2017, 09:27:30 pm
content: Hmmm, so is the little PCB a standard protection circuit or a Li-Ion charger please ? I was expecting just over-current/under-voltage protection in the pack.SeanB, any chance of a link to the PCB's that you purchased please ?Best WishesFraser

author: Fraser
author_rank: Super Contributor
timestamp: January 06, 2017, 09:39:48 pm
content: Just took a look on eBay and see that the PCB is just a protection unit and not a charger. I shall find a suitable board to use. A 2S 3A protector looks suitable.Fraser

author: bingo600
author_rank: Super Contributor
timestamp: January 06, 2017, 09:47:12 pm
content: Quote from: Fraser on January 06, 2017, 09:39:48 pmThe Scope is giving 8.3v out to the batt pack (well PCB) , i measured 3.67v on the top pack when charging (not fully charged) , and 7.29v across both packs.Could you use something like this ?http://www.ebay.com/itm/122216180572What's the BM pad for , is that the one going to the bottom pack's minus ??/Bingo

author: Fraser
author_rank: Super Contributor
timestamp: January 06, 2017, 10:00:07 pm
content: Hiya bingo600Many thanks. Yes that is the type of protection board I will use.Best WishesFraser

author: SeanB
author_rank: Super Contributor
timestamp: January 07, 2017, 11:27:39 am
content: Similar board, it does both charge and discharge protection, and disconnects on overvoltage ( though I would be careful there not to exceed the controller input voltage with the charger circuit) and does some balancing of the 2 cells. You slip it between 2 cells normally in a pack, or find some way to tape it to the sleeve of the one cell in a long string of single cells. Preferably with the IC side in some thermal contact with the cells so it can do a little thermal sensing of cell temperature if it has compensation built in, but often there is none, and some do have a thermistor connection to sense cell temp.