1, the solution capacitor is cylindrical and has two pins, one is long and the other is short, the long one is positive and the short one is negative, which can be abbreviated as long positive and short negative. When connecting, just connect the long anode and the short cathode.
2, point solution capacitance, ceramic capacitance is this circle, it has no positive or negative points, usually used in high stability oscillation circuits, as circuits, bypass capacitors and pad capacitors.
3. Polyester capacitors. Generally speaking, polyester capacitors are flat rectangles with no positive and negative poles. It plays the role of filtering, oscillating, power decoupling, bypassing and coupling pulsating signals in the circuit.
Recommended method for measuring capacitance:
1, measure capacitance with multimeter.
Before measurement, we should do a good job of discharging, that is, remove the components to cause a false short circuit, and then look at the capacity written on the label and adjust the gear of the multimeter. The general gear is R* 1K, and the gear adjusted here should be greater than the value on the label. Then, press the switch on the measuring instrument and see the value on the display screen, which should be close to the value on the label, indicating that it is available.
If it is a pointer type, the same is true. After discharge, it is proved that the pointer is restored or close to the value.
2, digital multimeter diode detection capacitance
This method is to put two red and black pens on both sides of the capacitor respectively. If the instrument makes a "drip" sound, it means there is a problem, otherwise there is no problem and the capacitor has not been broken down. Of course, set the multimeter to the diode position before the test.
3. Capacitance resistance test
This can check whether there is leakage, short circuit or other phenomena. Before testing, set the multimeter to R* 10K, and touch the capacitor pin with two pens at will. If the resistance value is zero or swings to the right, it proves that there is leakage or internal short circuit.