Bumble Bee capacitors: Difference between revisions

no edit summary
No edit summary
No edit summary
Line 16: Line 16:
3) Check for drift in capacitance:  Discharge the capacitor.  Measure it with a capacitance meter.  If it is outside the original tolerance range, it should be replaced.
3) Check for drift in capacitance:  Discharge the capacitor.  Measure it with a capacitance meter.  If it is outside the original tolerance range, it should be replaced.


4) Measure the ESR:  Discharge the capacitor.  Calculate the frequency at which the reactance of the capacitor should be 0.1 ohms.  Set a 50-ohm signal generator to that frequency and an amplitude of 1 volt.  Connect the signal generator to the capacitor.  Probe the voltage across the capacitor with a good oscilloscope.  There should be less than 10mv of AC voltage across the capacitor.
4) Measure the ESR:  Discharge the capacitor.  Calculate the frequency at which the reactance of the capacitor should be 0.1 ohms.  Set a 50-ohm signal generator to that frequency and an amplitude of 1 volt.  Connect the signal generator to the capacitor.  Probe the voltage across the capacitor with a good oscilloscope.  There should be less than 100mv of AC voltage across the capacitor.


5) If the capacitor passes these three tests, it is probably OK, and the lifted terminal can be resoldered.  It is a good idea to somehow mark the capacitor as having been checked.
5) If the capacitor passes these three tests, it is probably OK, and the lifted terminal can be resoldered.  It is a good idea to somehow mark the capacitor as having been checked.