Zeeweii DSO1C81

[Aldo22]

A new cheap 1-Ch handheld scope from Zeeweii: DSO1C81

Not much is known yet.

Probably 80MHz 300MSa/S
It seems to use an AGM AG32VF

Price seems around 200 Yuan.

Probably some kind of upgrade of the quite popular DSO154Pro with more bandwidth and a proper case for not much more money...

[piggy.dai]

Here is a picture of the disassembly from a Chinese netizen:
https://www.mydigit.cn/thread-461249-1-1.html

[Dave_g8]

Hi,
Seems a nice little device and if the cost is comparable with the DSO154Pro it will probably do very well given the well thought out user interface.
Zeeweii obviously think that there is still a market for the low-end single channel oscilloscopes.

Notes
- Looks like a 2-channel ADC, probably interleaved to increase performance for the single channel implementation.
- The AG32 is a higher pin count than the DSO154Pro and although the base specifications are the same there is more IO pins available.
- Looks like it has a solid state relay for AC/DC input selection.
- Will USB image download be supported?
- Does it require a protected 18650 battery and will that be included?

[Aldo22]

Seems a nice little device and if the cost is comparable with the DSO154Pro it will probably do very well given the well thought out user interface.
Zeeweii obviously think that there is still a market for the low-end single channel oscilloscopes.

I guess (pure speculation) that it will cost around $35.
It has to fit between DSO154Pro and DSO1511G in price.
No idea how much sense that makes.

[piggy.dai]

With 1500mA 18650 battery, USB download images don't seem to be supported, and it is not indicated in the introduction

[Aldo22]

Now it's on Aliexpress:
https://www.aliexpress.com/item/1005007393992391.html

The price is in the middle between DSO154Pro and DSO1511G, as I had expected.

Interesting are the 60KPts storage depth, FFT frequency measuring, zoom mode and the 20MHz bandwidth limitation.

[tunk]

The manual is now out:
http://www.sigpeak.com/download/zeeweii-DSO1C81_manual_EN.pdf

[Aldo22]

I think it is probably the best (hobby/toy) scope at this price.
Whether it will be a market success, I don't know.
With 2 channels maybe, but as it is it seems a bit like "too little, too late".
The DSO1511G has been around for longer and doesn't cost much more.

[tunk]

They seem relatively honest about their product specs
(as opposed to e.g. Fnirsi). Too bad they don't activily
promote their products - e.g. Zoyi/Zotek and Fnirsi send
free review samples to youtubers and bloggers.

[ptluis]

Max voltage 220V with 10x probe selection 
Instead of improving the 2ch model dso2512g or even release an improved version, they release a toy for some profit?

[Aldo22]

Max voltage 220V with 10x probe selection 

Yes, strange.
Does this perhaps only have to do with the standard probes?
I mean 40V (x1) should actually result in 400V (x10).
100V/div should also be enough.

[ptluis]

Max voltage 220V with 10x probe selection 

Yes, strange.
Does this perhaps only have to do with the standard probes?
I mean 40V (x1) should actually result in 400V (x10).
100V/div should also be enough.

exactly 400V that's what I expected too. maybe the pcb has some problems dealing with signals above 40V on the input module. I'm not really expert in scope electronics it's just a guess.

[Fungus]

Maybe it's not a physical limitation.

Maybe they just don't want people poking at industrial 3 phase supplies with these.

[Aldo22]

Maybe it's not a physical limitation.

Maybe they just don't want people poking at industrial 3 phase supplies with these.

Yes, I think so too. Either that, or a typo.
The scope shouldn't care as long as the probe doesn't supply more than 40 volts at the BNC. The scale (max. V/div) is sufficient.

[Fungus]

More likely just laziness by whoever wrote that.

Never equate to stupidity that which can adequately be explained by laziness and ignorance.

[Aldo22]

Btw, what does 40V mean here?
40Vpp or 40Vrms?
That's quite a difference.

Thanks.

[ptluis]

Btw, what does 40V mean here?
40Vpp or 40Vrms?
That's quite a difference.

Thanks.

That's a good question

[wasedadoc]

Btw, what does 40V mean here?
40Vpp or 40Vrms?
That's quite a difference.

Thanks.

That's a good question

RMS is meaningless without knowing the waveform. For example, the peak to peak of a 100v rms rectangular wave with 5% duty cycle is vastly more than the peak to peak of a 100v rms square wave (50%  duty cycle).

Only peak voltage is a definitive spec.

[Aldo22]

RMS is meaningless without knowing the waveform. For example, the peak to peak of a 100v rms rectangular wave with 5% duty cycle is vastly more than the peak to peak of a 100v rms square wave (50%  duty cycle).

Only peak voltage is a definitive spec.

Hmm, but that would be strange, since 230V mains is in Vrms.
So that would only be about 14Vrms (sine) or 140Vrms at 10x?

My Hantek explicitly states the maximum values in Vrms in the manual:

Maximum Input Voltage:  300VRMS (10X)

[ptluis]

More likely just laziness by whoever wrote that.

Never equate to stupidity that which can adequately be explained by laziness and ignorance.

maybe laziness but I'm not interested in connecting this to 235V AC and find out it will blow at my face. 220V AC is not used anymore in my country it's 235V AC and some times at night 240V AC

edit: RMS values

[wasedadoc]

RMS is meaningless without knowing the waveform. For example, the peak to peak of a 100v rms rectangular wave with 5% duty cycle is vastly more than the peak to peak of a 100v rms square wave (50%  duty cycle).

Only peak voltage is a definitive spec.

Hmm, but that would be strange, since 230V mains is in Vrms.
So that would only be about 14Vrms (sine) or 140Vrms at 10x?

My Hantek explicitly states the maximum values in Vrms in the manual:

Maximum Input Voltage:  300VRMS (10X)

I don't understand what point you are trying to make in that first paragraph.

As for the Hantek spec, I repeat my assertion that without specifying the waveform shape it is meaningless. Agreed AC mains is usually sine but scopes look at many waveforms which are not.

[Gyro]

I don't know how common that style of PCB mount 18650 clip is (I've seen them for AA), but the end of the cell would be acquiring an extra layer of Kapton in my home.

[Aldo22]

I don't understand what point you are trying to make in that first paragraph.

Well, you say that a maximum of 40Vpp is possible at the input (BNC).
That corresponds to 14.4Vrms with sine wave respectively 144Vrms in 10x mode.
That would be far less than the European 230 volts.
I'm not sure if that's right.

I mean, my pathetic Fnirsi DSO-TC2 can do that -> Attachment

Plus Zeeweii writes in the manual:

4.How to measure 220V mains?
Answer: First remove the USB cable (isolation), then adjust the probe to the 10X
position, adjust the vertical sensitivity to 100V, and adjust the time base to 10ms, and
then connect the probe to the neutral wire and the live wire (be careful!).

So the specifications are probably in Vrms.

[Aldo22]

I think I know how to read it now.
It's totally nuts. 

The first value (40V 1x) is in Vp (not Vpp), the second value (220V 10x) is from the marketing department. China has 220V mains, they just want to say that it is suitable for mains.
The technical limit is probably 283Vrms (sine).

Who wants to try it out? 

[ptluis]

Who wants to try it out?