NI-210SC curve tracer

[mojoe]

I just bought one from Amazon. It was shipped from China, but arrived in one week, instead of the usual 2+ weeks. It even cleared customs quickly.

I did open it. It looks just like the pictures posted here, but mine says V1.4. As the other post shows, it has two 4V batteries.

https://www.eevblog.com/forum/metrology/v-i-curve-tracer-component-tester/msg5802807/#msg5802807

I mostly bought this for two reasons: it allows probing two devices for comparision; and the built-in screen, so it doesn't require a scope. For just one channel, I've already cobbled together a scope and siggen with a couple of resistors for a functional curve tracer.

On my scope, the sinewave output reads 8.8 Vpp. There is a very slight offset bump at the zero crossing point. The voltage level stays consistent at different output frequencies. The frequencies look to be decently accurate.

For curiosity, I wanted to see the smallest value cap that it would work with. Of course, I had to use the highest frequency. When set this high, the capacitance of the probes show the flat line as a very thin ellipse. With a 10-20 pf cap, you can just see the ellipse get a bit fatter.

I knew it wouldn't test most zeners, but I tried a variety that I had on hand. You just start to get a zener knee with a 4.7 V zener. For some reason, it displays better with the highest resistance setting, implying the lowest current. A 3.3 V zener displayed the full knee. So far, that's the only thing I would fault this device for - no higher voltages. I did see that the NI-210G has selectable voltages, but that requires a scope. I may look at getting one of those, later. Right now, it looks like I can only get one direct from China, and the pricing is a bit high. At least with Amazon, I can return things easily.

When in single channel mode, the blue jack outputs a relatively fast rising 5 V pulse (positive and negative) with an exponential decay, at regular intervals (I forgot to measure the time). In dual channel mode, you of course get a sinewave on both A & B for comparing two boards. The pot marked "ALT" only works in A/B mode to adjust the vertical position of the B trace.

It comes with two probes (red & black) and two alligator clip leads (red & black). I took a spare red probe and painted it blue, to use for the B channel. I will use the spare black probe for the second ground when using both channels.

The circuit board looks well made, with good soldering. I may have gotten a used device, as the screen is somewhat scratched. I'll see if the vendor will do anything about that.

I didn't charge it before playing with it. It read three bars. After about 15-20 minutes, it did an auto shutdown. I am charging it now, so I'll see if the battery meter is any more accurate, later. Unlike many devices, this actually charges from a USB-C to USB-C cable.

I may have more to say after I've used this in dual-channel mode. I actually have something that needs repairing now, which is why I bought this. I've never used a Huntron, but I thought I'd give this similar device a try. I don't know yet if I'll find it useful or not.

[mojoe]

I just used this for a few hours. It was very helpful in finding some bad components that a DMM was ambiguous about, considering the other components in circuit. Yes, I had a working PCB to compare against. Even without a second PCB to compare, I found that it was still useful in some instances to help confirm my suspicions after using a DMM. Those curves can tell you more.

The only problem is that this curve tracer is defective. It keeps shuting down while I'm using it. It may be  the battery, even though it was freshly charged. I don't think there is an auto shutdown, as the interval isn't fixed, and it shuts down while I'm actively probing a circuit.

It came with no documentation, but I did find some online. There was no mention of an auto shutdown, or a settings menu. I tried powering it on while holding various keys, but no hidden menu appeared.

I am returning it, and ordering a replacement from a different source. As I mentioned previously, I may have gotten a used unit, as the display had many fine scratches, even though there was a protective film on it.

I've never used a Huntron. Now that I've seen what this type of device can do, I like it. And of course, it helps satisfy that urge for more test equipment 

Now to place another Mouser order.

[mojoe]

I found some other documentation online. It says, "no operation for 15 minutes, automatic shutdown". Well, it keeps shutting down while I'm actually probing a circuit, so I'd say it was defective.

[kmoonwalker]

try to monitor battery voltage how it behaves when it shuts down

[mojoe]

I'm returning this, so I'm not willing to spend much more time on it. I did find that it won't shutdown if you press a button before 15 minutes has elapsed. A lot of good that does. Probing a circuit counts as "operation", so it shouldn't shut down.

I did take this picture of the PCB. I see that one IC and ten passives are not populated. I always wonder what functionality is missing, or circuit stability is compromised when I see missing parts. Perhaps with those missing parts, the auto shutdown works properly?

Since they've removed almost all of the IC markings, I can't even see if there is anything I could do to defeat the auto shutdown. That one marked IC at the top is a battery charger.

Darn shame. Except for this auto shutdown problem, it's a nice unit. It's just a major nuisance having to remember to press a button every few minutes while I'm in the middle of troubleshooting.

Edit: I even tried leaving the USB-C charger plugged in. It still shuts down at 15 minutes.

[mojoe]

Taking another look at the posted picture of the V1.3 PCB, the top half looks quite a bit different, but the bottom half looks identical. That version is still missing a few parts, though. I see that the older board has a few ICs still marked. The only one I can read is the uC: AT32F403ACGT7. Here is a link: https://www.arterychip.com/en/product/AT32F403A.jsp

This still doesn't help me, though. I've messaged RAPo to ask if his shuts down while probing, but not pushing buttons.