What are the consequences of polarized electrolytic capacitor welding?

Electrode capacitors are usually electrolytic capacitors, and electrolytic capacitors are made from electrolytes.

Through the production of a certain process, a relatively large capacitance is obtained.

However, at the same time, there is a phenomenon that reverse connection will leak electricity. In order to avoid leakage in use, the capacitor is marked with polarity so that people do not connect it in reverse.

The capacitor will burst open, because the electrolyte inside will electrolyze the gas when it is reversed, resulting in an increase in internal pressure, and the capacitor shell will be broken and the electrolyte will overflow when it reaches a certain extent.

Tantalum capacitor electrolytic connection is basically in a short-circuit state, the power supply can not be added, if the power is forcibly turned on, it will soon paste the scorched taste, if it is not cut off in time, it is often like a small fried soybean.

The aluminum shell electrolytic capacitor is reversed, the low voltage, the charging voltage is much smaller than the capacitor withstand voltage, the leakage is large, and the heat is generated.

If the energizing voltage is close to the withstand voltage, it will leak at least and ** at worst. The better quality aluminum shell electrolytic capacitors are open at the top of the shallow groove with a "k" shaped point, which acts with the convex and concave lines on the surface of the grenade, and the groove is weaker than the entire aluminum shell.

The early aluminum shell electrolytic capacitors, most of them are not slotted, once they are reversed, they are very terrible, especially the voltage of several hundred volts, many ** aluminum shells fly up from the inner core, embedded in the roof or ceiling, the power can be seen, if the consequences of hurting people can be imagined.

The newer the aluminum electrolytic capacitor, because the electrolyte has not dried up yet, the heat of the reverse connection vaporizes the electrolyte, so the consequences of the reverse connection are more serious.

The electrolytic capacitor electrolyte is corrosive, and once there is a leak or **, the splashed equipment will suffer if it is not cleaned in time.

Therefore, the key is to prevent the electrolytic capacitor from being reversed.

Once, Qianlong asked Liu Luoguo, a big pit, one zhang in diameter, one zhang deep, even people and horses fell down, except for people and horses, there is nothing to use, how to come up.

Liu Luoguo thought for a long time and said, yes, yes, yes, is it blind?

Qianlong: No.

Liu Luoguo: Is it a blind horse?

Qianlong: No.

Liu Luoguo: Is it a dark sky?

Qianlong: No.

Liu Luoguo: How did it fall?

Capacitor is a kind of energy storage device, which can be divided into polarized and non-polarized; Ordinary medium, electrolytic, tantalum medium, etc. Polarity is generally made of electrolytic layer as an insulating material, and because of its very small thickness, a large capacity [electrolytic capacitor] is obtained. It is precisely because of the electrolytic layer for insulation, so it has to work under the condition of dielectric polarization, which also produces corresponding shortcomings:

Polarity cannot be misconnected.

The results of reversed polarity depend on the performance of the capacitor itself and the task it plays in the circuit at the time.

If it is in the filter circuit behind the rectifier, it will be broken down by the DC voltage after the reversal, and if it is in the open circuit state after the breakdown, it will cause the loss of filtering effect and make the ripple very large, and it cannot be used in occasions that require constant voltage (such as supplying power to audio equipment); If it is short-circuited after breakdown, the situation is much worse: the fuse will be burned at the least, and the regulator transistor in series will be damaged, and even the rectifier bridge and transformer will be damaged, and the capacitor may smoke and ** may exist. In more serious cases, it may cause a fire!

If it is used as a DC-blocking capacitor in the amplifier, it can cause the amplifier working point to be abnormal, and the amplifier cannot work normally;

If it is used as a comparison device in the test instrument, it will cause wrong measurement instructions, or even the instrument will not work;

If it is used in a timing circuit with a long delay, the timer will not work.

Similar situations can occur in other applications, and the impact or hazard can be analyzed according to the task performed by the capacitor. From the above analysis, it can be seen that not the polarity will be immediately ** once it is reversed, but that danger exists.