Cheezeball DC Load: DL24P: Pump, or Dump ???

[fubgumfaw]

but so far as i can see (in the "manual") it is missing a diode/zenerdiode test function?
.. and it looks like that it is only available from Ebay China /Ali ?

I saw the ms8911 on ebay, but nothing about a diode test feature. Where are you seeing this?

[beanflying]

Being fair the Mastech is nothing like either the LCR or Smart Tweezer offerings but it does fit into a price point. Best if this discussion goes to a more recent thread maybe than divert this one

https://www.eevblog.com/forum/testgear/lcr-tweezers-test-and-analysis/msg3441426/#msg3441426

https://www.eevblog.com/forum/blog/eevblog-1335-miniware-$70-dt71-lcr-tweezer-review/msg3226130/#msg3226130

or the one still in development thread.

[bianchifan]

Thome thoughts..

OFFTOPIC:
-MS8911
Some years ago the ELEKTOR magazine declared it to an absolutely must have for every hobbyist, nowadays they switched over to DT71.
Some german bloggers recommended the Mastech, too. And still remain.

Other bloggers proclaimed HP4070 and last year I was willing to order one.

But on some easteuropean and (esp.) russian forum I learned actual HP4070 = HP990C, no more hacking, accuracy no more 1%...
So I went out to find some info about DT71.
And I found some interesting stuff, especially a comparison of DT71 with UT116C.
Result: Depending on the scope sometimes one outperforms the other and vice versa.
All in all the DT71 is quicker and more accurate but it lacks sometimes at capacities and LEDs.
So I decided to order an UT 4 months ago but some sort of virus made the journey very long.

BTW... SMD testers are TESTERs and no high precision measurement instruments

ONTOPIC:
I ordered a 4wire DL24 on Ali's 11.11 SALE and it arrived last year and is still lying in the edge due to custums stress with batteries.
I bought it for capacity test with selfwelded battery packs, 10s and 13s.
The manual tells:
Test voltage 150V, working current 20A.
On russian forum I learned:
Never ever more than 150V! (no prob for me)
10A max, absolutely!
Looking at the traces I guess its right, 20A seem to be utopic.

[fubgumfaw]

I ordered a 4wire DL24 on Ali's 11.11 SALE and it arrived last year and is still lying in the edge due to custums stress with batteries.
I bought it for capacity test with selfwelded battery packs, 10s and 13s.
The manual tells:
Test voltage 150V, working current 20A.
On russian forum I learned:
Never ever more than 150V! (no prob for me)
10A max, absolutely!
Looking at the traces I guess its right, 20A seem to be utopic.

No idea about the voltage. I've tried 82v as the highest I have gone, but the amp draw was super low...less than 2 amps. My 82v EV pack is about 50Ah. At that loooow current draw it would allow me it would take a VERY long time to test capacity and then be unrealistic. I did think the 200v spec was probably wishful thinking.

After beefing up traces and a few other fixes you can run at 10 amps continuous and more.

[ThermallyFrigid]

yEAH,
I have one.  Works flawless.
Running a test right now on some 35ah SLA's
No problems up to 10Amp tests so far.  No magic smoke.

[fubgumfaw]

yEAH,
I have one.  Works flawless.
Running a test right now on some 35ah SLA's
No problems up to 10Amp tests so far.  No magic smoke.

I see 3.9 amps, not 10 amps. See about running it on 10 amps continuous. Did you add the zener to the gate? At low maps like you are showing, these things tend to run OK as is.

I have a couple of the DIY boards coming from Aliexpress. They should be here about the same time as my IXYS mosfets. Then I'll place a mosfet top and bottom on the board. I should get something like 20+ amps continuous.

[radud5]

I replace Mosfet with FDL100N50F (genuine from mouser with 2500W for 25°C, 1200W for 90°C, 500V, 100A, TO264 case), diode with STPS60SM200CW 60A/200V, use water cooler with Arctic Silver 5 and cooled shunt with an aluminum sheet and slight thermal pad. I have 60°C on Mosfet for 600W continuous load. Now the problem is thin of PCB track, which heat up when the current exceeds 18A.

[fubgumfaw]

I replace Mosfet with FDL100N50F (genuine from mouser with 2500W for 25°C, 1200W for 90°C, 500V, 100A, TO264 case), diode with STPS60SM200CW 60A/200V, use water cooler with Arctic Silver 5 and cooled shunt with an aluminum sheet and slight thermal pad. I have 60°C on Mosfet for 600W continuous load. Now the problem is thin of PCB track, which heat up when the current exceeds 18A.

I originally thought the lower left screw was a toggle switch in a small piece of aluminum, but that's your heat sink for the shunts.
Where's your zener for holding down gate drive?

I have four IXYS TO-247 IXTH130N20T mosfets that arrived yesterday from Mouser. I plan to put 2 of them in parallel. One on top, one on the bottom of the board. My factory diode is on my over sized heat sink, but I like your idea of beefing that up. I added copper to the current traces.

[mnementh]

I replace Mosfet with FDL100N50F (genuine from mouser with 2500W for 25°C, 1200W for 90°C, 500V, 100A, TO264 case), diode with STPS60SM200CW 60A/200V, use water cooler with Arctic Silver 5 and cooled shunt with an aluminum sheet and slight thermal pad. I have 60°C on Mosfet for 600W continuous load. Now the problem is thin of PCB track, which heat up when the current exceeds 18A.

LOL... Looks like this guy cut straight to the end of the book, and put all the mods I tossed out there in my random musings into one build. 

mnem
 

[interflexo]

How does as far as the voltage sense accuracy is concerned the 4 wire version compares with the 2 wire modded solution (on first page of this thread) when using less than 8A discharge current?

They probably take the "+ sense" terminal to the 150K resistor but I wonder if they also take the "- sense" terminal to the measuring 16 pin IC traces.

[fubgumfaw]

How does as far as the voltage sense accuracy is concerned the 4 wire version compares with the 2 wire modded solution (on first page of this thread) when using less than 8A discharge current?

They probably take the "+ sense" terminal to the 150K resistor but I wonder if they also take the "- sense" terminal to the measuring 16 pin IC traces.

I guess to know that you'd have to do a side by side comparison between the DL24 and DL24P. As far as I know everyone on this thread has the newer DL24P.

[interflexo]

No need for that. How far off is the voltage sense in a DL24P during discharge (more than 6A) when compared with a multimeter in the battery terminals?

[fubgumfaw]

No need for that. How far off is the voltage sense in a DL24P during discharge (more than 6A) when compared with a multimeter in the battery terminals?

Got it...
1. My original DL24P...which no longer turns on the mosfet because the pin on the CPU that drives the mosfet is blown...that one measured voltage to better than .1v variation with my 4 digit Extech EX520. I don't have a 5 digit DMM which is what the DL24P LCD "appears" to have.
2. I have 2 of the DIY boards that arrived a week ago. I have not had time to try them out yet.

It's just an opinion I suppose, but these boards are not exactly well designed and are fairly cheaply made. When I saw the 5 digits of accuracy on the LCD...I was rather skeptical it was real. There's no calibration done on them and I seriously doubt testing them further than a quick power up is done after they are made. I think you get what you pay for and these devices are cheap...so there you go.

[Hamelec]

No need for that. How far off is the voltage sense in a DL24P during discharge (more than 6A) when compared with a multimeter in the battery terminals?

that is not the problem, you need the 4 wire version to compensate the resistance of your WIRES to the power source.
e.g if you have 0.1 ohm wire resistance (and twice) and 6 A then the voltage measurement is 1.2V off.... and so also the cutoff voltage....

[interflexo]

No need for that. How far off is the voltage sense in a DL24P during discharge (more than 6A) when compared with a multimeter in the battery terminals?

that is not the problem, you need the 4 wire version to compensate the resistance of your WIRES to the power source.
e.g if you have 0.1 ohm wire resistance (and twice) and 6 A then the voltage measurement is 1.2V off.... and so also the cutoff voltage....

I am aware of that. And does it perform well in that regard? That is my question.

Thanks fubgumfaw.

[bianchifan]

New model, split type - up to 600W

DL24M

[wasyoungonce]

Has a remote display...which is a good idea.  I recently purchased a DL24P and hate where the display sits.   I only use it for power and current stuff so far I love it but find the UI hard to decipher.   Don't get me wrong I love the unit.

The BT app works but the graph scale is useless, I'll have to try this to a computer.

I'm glad I got it......my first active load.     Even testing a cheap 12V cigarette plug adapter @3A, the contacts inside were poor and started melting the plug....its a cheap piece of rubbish.   But an excellent test nonetheless

I'll mod mine with the gate zener and probably a better FET.  I had to mod the included 12V 2 pin (110V plug) supply for 230V AC Aussie plug (its multi I/P voltage capable).  I read its not a good supply....but...meh work for the moment.

I loved it so much I purchased a RIDEN USB load UM34/UM34C .  Makes measuring so much easier...I'm sick of resistors high wattage and burning myself.  I'm glad I got it....so glad I suspect I'll buy a better one in the future as I understand my needs and uses more.

   Thanks EEVBLOG folks.

[bianchifan]

Has a remote display...

Not only...
- 4th mode Constant Resistance was added
- new analyzing function automatic internal resistance
- current resolution in mA choosable

[fubgumfaw]

Has a remote display...

Not only...
- 4th mode Constant Resistance was added
- new analyzing function automatic internal resistance
- current resolution in mA choosable

I just got a nerd boner! And dammit...just bought 2 more of the DL24P's a month ago! Oh well...bought 2 of the DL24M 600w version...see them in a month!

[interflexo]

I also ordered some DL24M. I will post here the tests feedback. I hope they are full backward software compatible.

[fubgumfaw]

I also ordered some DL24M. I will post here the tests feedback. I hope they are full backward software compatible.

I'm not sure why its this way, but why does aliexpress typically take 5 days before they show shipping activity? My DL24M's finally show they shipped today.

[interflexo]

Sometimes the seller needs some days to source the goods. They don't stock it "in house".

[fubgumfaw]

Sometimes the seller needs some days to source the goods. They don't stock it "in house".

Yeah...maybe. So Atorch doesn't carry their own products? How about QSmotor? I don't buy from many sellers, but they all seem to take 5 days before they ship.

[mnementh]

It's a nationwide contest to see how many pissed-off Americans they can get shitposting them on AliEx every day. 

The 5 day wait is just tenderizer before the main course...

mnem
Doesn't everybody know this...?

[fubgumfaw]

It's a nationwide contest to see how many pissed-off Americans they can get shitposting them on AliEx every day. 

The 5 day wait is just tenderizer before the main course...

mnem
Doesn't everybody know this...?

Very funny and probably true...