Johnlite emergency light

[Darwin1138]

Hello, my neighbour gave me an emergency lamp that he bought years ago but he never got around to use it or even take it out of the box. I recharged it and it operated normally, a month later the lamp doesn't work, I suspected a busted battery and upon disassembly the 6V battery only measures 2.2 V, time for a new one. Then I measure the voltage when charging just to make sure that the control board is fine and I found that the charging voltage is 14.56 V.

Then I removed the battery and connected the terminals to a power supply and the lamp turns on in 12V but also in 5V.

Now I don't know what to do. Do the logic board failed? but manages to turn on the light with 12V and 5V. Or they put the wrong battery in the factory??

 

[eljefino]

Hook a different 6V battery up to check its charging voltage. Doing it with no load, and a cheap DVOM, will read super-high.

 

[Chris142]

way off topic but whats tht blue circle on his meter for? left side with npn and pnp on it? all mine have that too.

 

[tom slick]

Originally Posted By: Chris142
way off topic but whats tht blue circle on his meter for? left side with npn and pnp on it? all mine have that too.


Testing transistors

 

[Darwin1138]

That is to measure the amplification factor of a bipolar transistor and said transistors come in two types according to their construction PNP or NPN