3.5mm headphone jack with 5.1-channel audio high-fidelity different structure design, with a variety of functions to choose from, installation options are DIP and SMT for choice. The contact terminal adopts an elastic structure design to ensure a good and stable contact life.
3.5mm headphone socket use: applied to various digital voice information terminals such as mobile phone stereo design, CD player, wireless phone, MP3 player, learning machine, DVD, digital camera, etc. Specifications: Welding temperature 260 ± 5 ℃ 10S, mating force 3 ~ 20N, life 5,000 times 3.5mm headphone socket Generally speaking, the wire made of a certain material can withstand the current density, not the current. strength. Because different thickness wires can withstand.
一 、 3.5mm headphone socket measuring voltage method
The first thing to check is whether the voltage of the power pins of each chip is normal, and then check whether the various reference voltages are normal, and whether the working voltage of each point is normal. For example, when a general silicon transistor is turned on, the BE junction voltage is about 0.7V, and the CE junction voltage is about 0.3V or less. If the BE junction voltage of a triode is greater than 0.7V (except for special triodes, such as Darlington, etc.), it may be that the BE junction is open-circuit signal injection method. Add the signal source to the input terminal, and then measure the waveform of each point in turn to see if it is normal to find the fault point. Sometimes we will use a simpler method, such as holding a pair of tweezers with your hand, and touching the input terminals of each level to see if the output terminal responds. This is often used in audio and video amplifier circuits.
It must be that the thicker the wire can withstand the higher the current intensity. But the current density is different. No matter how thick the wire is, the current density it can bear is not much different. The current strength is only related to the cross-sectional area of ​​the wire. For example, the current is 10 amps. No matter how thick the wire is, the current strength is 10 amps. For example, there is a current of 10 amperes through a wire with an area of ​​1 square millimeter and a current of 10 amperes through a 10 mm 2 wire. Their current strength is the same, both are 10 amps, but the current density is different, of course, it is 1 square The current density in the millimeter wire is high. In this way, if there is a problem with the current transformer, neither the circuit breaker nor the arrester can remove the fault. The fault will be removed by the trip of the upper-level circuit breaker, which will expand the power outage. At the same time, the current transformer will be burned due to the delayed removal of the fault.
Two, 3.5mm headphone socket inspection control
1. The quality department QA conducts random inspection on the products in the delivery process, and the acceptance standard C = 0 sampling plan
2. Train the inspectors on inspection standards once a year, and issue a job certificate upon passing the exam.
3. Sampling for internal inspection: During the inspection process, the team leader conducts random inspections on the results of the inspection positions within the specified time interval, and corrects and counsels on site
4. Goal management: Set missed inspection goals for inspection positions, workshops set overall goals and objectives assessment methods; review and monthly summary. Both the increase and decrease of missed detection rates must be summarized.
单 When single-phase grounding occurs on the user side, because the circuit breaker does not trip, in order to find the ground point, the off-line branch of a public line on the contract must be pulled one by one, which will also cause the public line to be deactivated and the power outage will be increased. The tact switch is mainly assembled by the following parts through the corresponding process:
1, plastic handle (Material: generally POM material, if the requirements of fire resistance, flame retardant and high temperature resistance, PA nylon material is often used. Process: injection molding)
2, Insulating base plate (Material: Bakelite; Processing technology: Stamping)
3. Terminals (Material: Phosphor bronze generally; Processing technology: Silver plating)
4.Iron case (Material: generally iron; treatment process: nickel plating or black pot process to prevent oxidation)