As an indispensable accessory in many digital products, the performance and basic usage of headphone socket must be understood. We will give you the best guidance and understanding in these areas, the following is the specific details.

First of all, it is necessary to confirm whether the pins of DC power supply sockets and headphone sockets of each chip are normal. Secondly, it is necessary to check whether the reference voltages are normal, and whether the working voltages of each point are normal. For example, when the socket is on, the BE junction voltage is about 0.7V, while the CE junction voltage is about 0.3V or less. If the BE junction voltage of a socket is greater than 0.5V (except for special sockets, such as AC power sockets), it may be the BE junction open circuit signal injection method. The signal source is added to the input terminal, and then the waveform of each point is measured back to see if it is normal to find the fault point. It must be that the thicker the conductor, the stronger the current it can withstand. But the current density is not the same. No matter how thick or thin the conductor is, the current density it can withstand varies little.

Sometimes we also use simpler methods, such as holding a tweezers in our hands, to touch the input terminals at all levels to see if the output terminals react, which is often used in audio, video and other amplifier circuits.

Current intensity is only independent of the cross-sectional area of the conductor. For example, current of 1 ampere is 1 ampere, regardless of how thick the current passes through the conductor, its current intensity is 1 ampere.

For example, a conductor with an area of 1 square millimeter has 11 amperes of current and a conductor with an area of 11 square millimeters has 1 ampere of current. Their current intensities are the same, they are all 10 amperes, but the current density is different. Of course, the current density in a conductor with a square millimeter is large. In this way, once the current transformer has problems, the circuit breaker and the arrester can not remove the fault, the upper circuit breaker trips to remove the fault, thus expanding the blackout scope, but also because of delayed removal fault, the current transformer will be burned. Later measurement of DC socket and headphone socket voltage measurement method

Above is the method of measuring the pressure of the headphone socket. Please pay attention to these problems before using it.