Connect an external power supply to vibration sensor MEMS V2

Hardware
1

Hello, I bought some time ago several 'Industrial IoT Wireless Vibration & Temperature Sensor V2 MEMS. We used these sensors with batteries for a few weeks. However, we now have to supply them with external 12VDC power because we need to increase the frequency of the readings.By the way, is it really 12VDC?

If I remember correctly, the first generation of vibration sensors had a current connector inside the case. So I opened the case of one of our sensors (v2) but I found no such connector.

So my question is: How can I modify the electronic board in order to be able to connect the external power supply to it? I did see two holes identified + and - but nothing is soldered to these holes (see the red rectangle in the picture). If these are the two holes that should be used, could you please give me the reference of the connector that should be soldered to these holes? This would save me a lot of time.

By the way, I will place a new order for sensors tomorrow.Therefore, I would like to know if it is still possible to plug the external power supply directly into the housing with the new version of the sensor with a 2.1mm power jack. My client prefers a hardwired solution.

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2

Yes, you can plug 12V supply in the +,- marking.

3

OK

Thank you

Have a nide day :slight_smile:

4

Hello Bhaskar,

We received our connectors today and tried to modify a sensor to work on an external 12VDC power supply. Unfortunately this did not work. The modified sensor is not accessible even in configuration mode, which makes us suspect an electrical problem.

Here are the steps we followed:

  1. We removed the battery holder from the case and disconnected the cover battery holder cable
  2. We have soldered a connector at the indicated place for the external power supply.
  3. We have tested the welds and they are correct.
  4. We then connected the external power supply respecting the polarities of the screw connector and then we turned the power swith ON (the little black switch).
  5. We finally tried to read the sensor data by pressing the ‘R’ button. As this did not work, we also tried to set the sensor to configuration mode without success.

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To try to ‘debug’ the problem, then

  1. We tried to reset the Digi module by connecting Pins 5 (reset) and 10 (ground).
  2. We tried to change the power switch position.
    But none of it worked

Please help us to solve the problem. Your help will be appreciated because we have 4 other sensors to modify.

Thanks

5

no this board wont work. this does not have on board supply to support external power supply.
the first pictures you shared has the power electronics.

6

Okay, I understand

I observed the following difference between the sensors: Those that can be converted for external power supply seem to have a black chip next to the holes to solder the connector. Is it the presence of this chip that indicates that the sensor can be converted. I guess it’s a current converter, isn’t it?

Thank you Bhaskar

7

yes the missing parts on this board are responsible for power conversion.

Thanks