Something wrong with this Black Gate Cap. Notice that its polarity is reversed. I got a -ve DC reading when I measure it the right way and I got a Positive reading when I reverse the +ve and the -ve.
What could be wrong and what caused this?
各位大哥,
這隻Black Gate好過份. 正常方式去度, 佢出 -ve DC 7.2 Volt. 將正負相反, 佢出+ve 7.2V DC. 出咗什麼問題, 點會變成咁?
The reson for posting this message is .... this capacitor has to keep the Polarity corrct. If I connect the +ve side to the -ve terminal by mistake, the cap will blow, right?
But from this Voltage measurement, it looks like the polarity of this cap is reversed! Is this a BAD cap now?
You cannot check voltage on a capacitor like this.........!
To check a capacitor , it is better to use a needle meter and see whether it will 放電 or not, otherwise, Ido not know of anyway to check the "voltage" of the meter.
You mean using a Analog meter? And when you connect it to the meter, you should see the "needle" dropping as the capacitor is giving out "power".
I don't know ... how do I know whether a capacitor is charged or not if I don't have a analog meter? If I put my fingers across the lead of a charged capacitor, I may be shocked given the voltage is high enough.
What should I do with this cap? Is it dead? I used the same method (though it may be stupid) to test ALL other caps I have (> 30), their polarity stays just like what is marked on the shield. Just this one gives me an "opposite" charge.
If it is NOT dead, how do we explain the "reversed" polarity? Really confused me ... sigh
The voltage of the meter is reversed for analog meter. Red will give -Ve and Black for +Ve. I do not know electronic meter is reversed or not. So the charge and re-charge meter will be reserved.