EEVblog 1723 - AlienTek DM40 Multimeter/Oscilloscope Review

[EEVblog]

Review of the AlienTek DM40 Multimeter/Oscilloscope
https://s.click.aliexpress.com/e/_c4EPQJod

00:00 - Alientek DM40C Multimeter and Oscilloscope
02:12 - Unboxing
03:51 - What's with the rotating tilting bail?
06:15 - Power on
08:53 - The Trend Chart is really nice
10:19 - Online/Offline mode, what IS this?
11:58 - Banana jacks please
12:07 - Megaohms interference issue
13:20 - Autoranging speed & Continuity & Diode
14:08 - No AutoHold
14:31 - Isolated inputs?
14:58 - Calibration checks
16:52 - Capacitance interference?
18:37 - Relative mode
19:10 - Colour LCD inside and outside
20:04 - Temp is a bit off
20:15 - No internal recording
20:53 - Reading memory
22:02 - Oscilloscope functionality
26:28 - Function Generator
28:46 - FFT
29:09 - Bluetooth functionality
31:33 - Three Finger Screen Shot
32:31 - It's got magnets!
32:51 - Teardown
37:56 - Analog front end
38:46 - Power consumption measurement
39:03 - PCB inspection talking head
45:08 - Conclusion

[TUMEMBER]

Review of the AlienTek DM40 Multimeter/Oscilloscope
https://s.click.aliexpress.com/e/_c4EPQJod

Dave, Unfortunately, the link doesn't work. Ali creates " access zones." For a split second, I see the product page, and then a "404 page" pops up. This "pig algorithm" targets the audience.

[Fryguy]

That 4 pin connector on the lower right looks like a serial interface to me .

V-D-C-G = Voltage-Data-Clock-Ground maybe ? 

[gamalot]

The resistor divider is from a Chinese maker, spec'd at 0.1% and 10 ppm/°C.

[free_electron]

That 4 pin connector on the lower right looks like a serial interface to me .

V-D-C-G = Voltage-Data-Clock-Ground maybe ? 

SWD for the arm ?

[free_electron]

anyone knows who makes those dc/dc transformers ? and what is the driver chip ? i've used the TI and maxim chippies, but these look from a different vendor.
the little trasnformers are interesting.

[gamalot]

anyone knows who makes those dc/dc transformers ? and what is the driver chip ? i've used the TI and maxim chippies, but these look from a different vendor.
the little trasnformers are interesting.

I couldn't find any info on the LT61-11x, but there's some available for the LT51-11x that you can use as a reference.

[Fungus]

Nice!

This could be the new recommended piece of test gear for newbies to get.

One thing: Does it work while plugged in? Can I powered it all day long with a phone charger?

[EEVblog]

This could be the new recommended piece of test gear for newbies to get.

I wouldn't say that because:
a) It's not cheap.
b) If you just want a multimeter then there is better bang-per-buck out there.
c) If you need a portable scope then there is probably better bang-per-buck out there.

[EEVblog]

Alientek said the iOS is available on the iOS store.

[octal]

This could be the new recommended piece of test gear for newbies to get.

I wouldn't say that because:
a) It's not cheap.
b) If you just want a multimeter then there is better bang-per-buck out there.
c) If you need a portable scope then there is probably better bang-per-buck out there.

Hi Dave,
what would you suggest as portable low cost scope?

[octal]

Nice!

This could be the new recommended piece of test gear for newbies to get.

One thing: Does it work while plugged in? Can I powered it all day long with a phone charger?

No it's not recommanded to use it while connected to charger. In the documentation they say:

2， DM40 integrates a rechargeable battery. For safety and measurement stability, please do not
measure while charging. Low battery reminders may affect accuracy. Please charge promptly.

[Fungus]

what would you suggest as portable low cost scope?

That depends 100% on what you want to look at.

[octal]

what would you suggest as portable low cost scope?

That depends 100% on what you want to look at.

Hi @Fungus
I already own a Rigol scope. This was not my tought when I asked the question. Dave stated that "c) If you need a portable scope then there is probably better bang-per-buck out there.", so I asked what kind/brand of portable scope do you consider as being a better solution than the DM40 (I mean in the same techno category and pricing level).

[Fungus]

I already own a Rigol scope. This was not my tought when I asked the question. Dave stated that "c) If you need a portable scope then there is probably better bang-per-buck out there.", so I asked what kind/brand of portable scope do you consider as being a better solution than the DM40 (I mean in the same techno category and pricing level).

Well... these things aren't cheap.

I thought they were $90 but that's click-bait pricing. If you want one with probes, etc., it goes up quite a bit. $150 is more realistic.

The thing I liked about this was the build quality and the touch screen.

If you want bang per buck you can get (eg) a 2-channel Zeeweii with two probes, etc. for $90.

It doesn't have touch screen but it does have voice control 

https://www.eevblog.com/forum/testgear/another-dsodmm-zeeweii-dso3d12-claimed-120mhz250msps/

[octal]

I'm not really fan of those low cost scopes, I work mainly in digital electronics and I always need signals decoding. No low cost scope implements it.
I'm planning to buy this DM40 B or C variant mainly to use it as quick debug tool. When I'm in a move or on my home desk where I can't really have all my measurement tools, I would like to have such small device to check voltage, use its scope to check the presence of I2C clock or spi data, ... it can be very handy tool.
Maybe there are better tools for such thing, I don't know. I hate tools that need a smartphone or a tablet. the DM40 has nice display and mainly big crisp fonts in multimeter mode, this is very handy for my poor old eyes.
As for the price, if you want the DM40C with all probes, you certainly need to pay 150€. This is not cheap for hobbyist, for me it's really acceptable price for such nice tool.

[Fungus]

I'm planning to buy this DM40 B or C variant mainly to use it as quick debug tool. When I'm in a move or on my home desk where I can't really have all my measurement tools, I would like to have such small device to check voltage, use its scope to check the presence of I2C clock or spi data, ... it can be very handy tool.

As for the price, if you want the DM40C with all probes, you certainly need to pay 150€. This is not cheap for hobbyist, for me it's really acceptable price for such nice tool.

The most common problem with I2C is the pullup resistors. These 'scopes are perfectly capable of seeing that.

I agree the DM40's a nice gadget, it seems like a fair price to pay for what's inside it.