Description

WE ARE RICH ELECTRONICS

Nippon Chemi-Con

Axial Electrolytic Capacitor

Details:

Despite being ‘new old stock’ these quality Nippon Chemicon caps. are still perfectly serviceable though they may need reforming… the procedure described below is given to aid the engineer but….

Please be aware these are electrolytic capacitors and by their very nature require a high degree of skill when handling and installing, they are intended for use by qualified electronic engineers, please do not purchase and engage in any of these procedures if you are not competent to do so!

Reforming Electrolytic Capacitors

• Manufacturers claim that most old electrolytics can be saved if the correct procedure is followed, regardless of how long they have been unused. Such capacitors must be “reformed”. This process consists of applying rated voltage through a resistance (about 30,000 ohms, five watt) for five minutes plus one minute for each month of storage (see figure 6). As the capacitor reforms, the voltage across the resistor will drop (measured at the Xs in Figure 6). If that voltage will not drop below 10% of applied voltage after one hour, the capacitor is probably beyond help.Reforming Electrolytic Capacitors – The process of reforming an old aluminum electrolytic capacitor consists of the application of rated voltage, through a resistor, for a period equal to five minutes plus one minute per month of storage.The electrolytics appearing on the surplus market have often been in storage for a very long period indeed. Some manufacturers use a visible code, of which the first two digits indicate the year of manufacture.The circuit shown in the sketch above works reasonably well. Apply the rated voltage through a 5W resistor. Anything from 20K-50K will do, as this is far from a precision process. The meter is used to measure the voltage drop across the resistor; when no current is flowing, there will be no drop. Obviously, when there is a large voltage drop (more than 20% of the applied voltage), there must be a significant current flow through the capacitor. The nature of a proper capacitor is to impede DC current flow, so when there is such flow, something must be wrong.Note: Apply the appropriate D.C. voltage to the capacitor with a D.C. power supply. An old Kepco, Lamba etc. tube regulated lab power supply rig works great. Be sure to observe the proper polarity!

For datasheet search…Nippon SL Series