Category: Product review

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18650 UPS modul product review

We ordered the 18650 UPS modul for testing purposes from China. The goal was to find a small / compact UPS power source which is capable feeding the device in case of power failures or power outtages. Further plans would be using solar energy so devices which are operate off-grid in areas where we cannot reach them quickly and easily can be deployed. Based on the description this modul would be ideal for our needs but unfortunately it did not. Herewith we would like to share our experience with you:

  • we did not checked the device right after it has arrived – this was a mistake!
  • it does not have polarity protection so we burned one of the units when inserted the battery cells incorrectly.
  • we are using high quality cells the output current and voltage is way below what was expected and promised
  • let’s see the facts, we bolded what was not fulfilled:
Battery protection(Over charge or Over discharge)
Micro USB port Input
Type-A USB Output
0.5A current charging
1 switch control USB output
5~8V Input Voltage
3V & 1A Output
5V & 2A Output
LED indicate(Green means full,Red means charging)
3V output port x3
5V output port x3
Be careful of “+” and “-“, You should follow the direction of “+””-” on the PCB.
If you put wrong direction, charging chip will be destroyed.
This product does not include 18650 battery
 

Evaluation: NOT RECOMMENDED

18650 UPS modul is still available on Aliexpress.com on.

18650 UPS shield
18650 UPS shield
18650 UPS shield 2
18650 UPS shield 2
18650 UPS shield no load
18650 UPS shield no load
18650 UPS shield with load
18650 UPS shield with load

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PNP or NPN transistor

PNP or NPN transistor, sometimes it is not that obvious. This little summary hopefully helps someone who still confused when and how to use them.

I would like to give you some ideas how I learned when and which to use.

  • current always flows from Collector to Emitter
  • Collector should be connected to the middle letter of the transistor [nPn or pNp]
  • Base will ‘open’ when connected to the first letter of the transistor[Npn or Pnp]
That would be our super fast super short notes from topic ‘PNP or NPN transistor’.
For more detailed information please visit Wikipedia.
Example part Collector Base Emitter Hint
BC212 Positive – Negative Positive + PointInPermanently
BC182 Negative + Positive Negative – NeverPointIn
PNP or NPN transistor - different type of transistors. [Wikipedia]