2-in-1 Voltmeter and Ammeter – Cheep Chinese Electronics: Part 2 – Getting the 2 in 1 working!

My plan today was to get this voltmeter/ammeter working. I had the day off work to go look at installing CCTV somewhere then to come home and spend the rest of the day trying to get this to work before I look after my daughter in the evening.

This did not happen as planned but… I have it working!!!!

I spent the car journey today figuring out how to get this working and spent a lot of time researching on the internet. I came across a helpful video on youtube demonstrating this working. I will link this below somewhere.

There were two things I knew about this after doing the research – you do not need to use a shunt with the 100v 10A version of this 2 in 1 as it is built into the device, which it actually is as I have found out. (I will insert a poor drawing showing this! Inserted) and you connect the red and black to the power supply and then the red and blue to the positive and negative of the load respectively.

My poor drawing of the wiring:

I felt rather confident when I got home that I knew what I was doing so I went for broke! One lesson I have learnt is that these are alright with a little bit of reverse polarity connections! woops. No magic smoke though so it was okay luckily! I need to pay more attention to the markings on cheap Chinese power adapters!

I got the 12v power supply, a 12v array of LED’s (also from china) and the 2 in 1. I connected the small power cables to the + and – on the power supply and it lit up. It does actually take anything from 4v to 30v it seems (I’ve now tested it with 5v, 12v and 24v). I then connected the larger red and black cables to the + and – on the power supply and low and behold the voltage popped up on screen! Winner!

So far so good. I then felt a bit more brave and ran a length of red cable from the + on the power supply to the LED array then joined the large blue cable to the – on the LED array.

Moment of truth!

Boom, there was the amperage showing up! All 0.28 of it!!! I have no idea how accurate this is in the slightest! The 12v was pretty spot on as I have measured this previously but I have not had chance to measure the amperage yet with my multimeter as with my excitement in getting it working I woke my daughter up! I did get chance to get some photos of it working and the connections to try and show this – I’m going to make some crude drawings tomorrow at work of the wiring I used to try and explain this a bit more but for now I will attach some photos of it set up and working!

Now for the next piece of cheep electronics I have in my box to test!

If anyone has anything they are not sure about buying yet – just get in touch and depending I will buy it and test it for you for free! I love the challenge of figuring out these things!

The link to eBay listing:

The working unit:
2015-02-12 20.11.41 2015-02-12 20.11.53 2015-02-12 20.12.23 2015-02-12 20.12.41 2015-02-12 20.12.46 2015-02-12 20.13.18 2015-02-12 20.13.372015-02-12 20.13.45

And the video that helped figure this out:

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