teardownit

    The packaging box is made of cardboard. A small window allows the user to identify the power supply model without removing it from the packaging. The power supply is built on the TEA18363 chip. It is a single-cycle DC-DC converter controller from NXP Semiconductors. The chip needs an external n-channel power transistor. The controller is designed for a flyback converter topology and focuses on maximum power efficiency with minimum components. This feature is listed in the datasheet footer: "TEA18363T GreenChip SMPS control IC". Structural diagram is traditional: input → filter → rectifier bridge → inverse pass converter with rectifier working for output C-L-C filter, regulation by the output voltage, the control signal is transmitted through the optocoupler. The power supply has no PFC. Careful assembly of the components. The quality of the connections is good. We consider placing the optocoupler, which is practically under the transformer, as a design disadvantage. If th...

The main influences in symmetrical cables are transient influences at the near and far ends. The influences are caused by parasitic electromagnetic and capacitive coupling between pairs of the same cable or several closely spaced cables. Devices for diagnostics and localizing faults in metallic cables are used to assess such transient influences. The primary method of reducing such influences is to twist the copper pair strands. The most stringent requirements are structured cabling with a wide range of operating frequencies. For example, no twisting is allowed at a distance of no more than 1/2 inch from the two cable segments' connection point. A transient influence measure is: - Near End Transient Attenuation (Near End Crosstalk, NEXT) - Far End Transient Attenuation (Far End Crosstalk, FEXT). These parameters allow you to assess the suitability of symmetric cable pairs for high-speed data transfer. The transient attenuation NEXT and FEXT can be expressed as the logarithm of the ...

Many guitarists consider the DS-1 to be the worst-sounding guitar pedal. Could this 1978 Roland design be a failure and is now hopelessly outdated? However, the idol of millions, Kurt Cobain, the author of world-favorite solos John Frusciante, and electric guitar classics Steve Vai and Joe Satriani either did not know that the BOSS DS-1 sounds terrible or managed to make it sound good. We can get a good sound out of this classic pedal, too. For that, we'll put it, listen to it, and start by studying the circuitry. Like most other guitar pedals, it is powered by a 9-volt battery. In the case of overdrive and distortion pedals, this battery not only gives you independence from the power supply but, oddly enough, also plays a part in shaping the sound. Lovers of vintage pedals also prefer vintage, saline-type batteries. The fact is that the Leclanche manganese-zinc cell has not only less capacity and durability but also a higher internal resistance than the more modern alkaline cell. ...

Earlier in the post ( link ), we tested the Lenkeng LKV373 kit and verified that the delay was insignificant - 0.067 seconds. We recently examined the Lenkeng LKV383PRO over-IP extender kit, which upset us. Let's look into what the problem is. What's the difference between a regular twisted-pair HDMI extender and an over-IP 1. Regular twisted-pair HDMI extender. The transmitter and receiver are connected to each other by a single piece of twisted pair (usually 130 to 330 feet). The twisted pair is used exclusively as some transport for specific signals. Video is transmitted in its original quality and without delay in this case. 2. Over-IP HDMI extender. Transmitter and receiver work on IP protocol, which means they can be connected to a local Ethernet network. The transmission range is limited to IP protocol, i.e., 330 feet. The range can be increased if a switch is connected between the transmitter and receiver in the middle. In this case, the video usually shows signs of sli...

  In some cases, a successful result can only be reached with excellent and proper grounding if the probing signal is applied relative to the ground. An incorrectly selected generator grounding location will prevent the probing current from flowing in the search direction if the line to be traced is branched. The transmitter ground point should be changed so the signal is fed in the right direction.   The circuit impedance to which the signal is applied (cable-ground) depends on the ground condition (its type and humidity), the physical parameters of the traced line (size, insulation, etc.), and the characteristics of the grounding. Some generators can match the output impedance to the signal circuit parameters to increase the signal amplitude. The grounding quality is essential for low frequencies. The better the grounding of the oscillator, the higher the signal amplitude. The ground resistance should be less than 1000 ohms. So a 5-gallon water canister will be helpful ...