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  AC measurements are useful for localizing core breaks. This is best accomplished for shielded cables by measuring each core's capacitance relative to the shield. Knowing the core capacitance C-linear, the length of the broken core can be calculated using the formula: Lpaire = Ccore-shield/C per length When measuring a broken circuit's core capacitance, the cores of the other circuits in the cable bundle are connected to each other and to a reliably grounded shield. If the capacitance measurement results of both cores are the same, they are broken in the same place. Different values indicate a break in only one core and in the one with the lower capacitance. The distance to the breakage point is calculated by the formula Lpaire = Ccore-shield/C per length, where Ccore-shield and C per length are the measured and the linear capacitance of the core. It's crucial to remember. Defects in the cable shield have a significant influence on the measurement result. With the help of

  Introduction HDMI twisted pair HDMI extenders are commonly used to extend the HDMI interface over long distances. This is a kit of transmitter and receiver that are connected to each other with twisted pair cable. Many manufacturers have the same design. But what if you need to transmit an HDMI signal and a USB signal? There are many devices for such cases. They are called HDMI KVM or HDMI USB twisted pair extenders. Both device types have HDMI in/out and USB ports on the body. But the functionality, purpose, and price of these devices are different. Let's take a look at these differences. HDMI KVM extenders This is the most mass type of active extenders, which can transmit not only HDMI signal over twisted pair but also USB. We need to know that in this case, USB is used only for keyboard and mouse connection; that's why this extender type is called HDMI KVM. Where KVM stands for keyboard, video, and mouse (a common term). Manufacturers so indicate to buyers that it is possi

  An electronic clock without a microcontroller is a circuitry masterpiece that can be looked at forever! Today we continue to explore the practical possibilities of pure logic. We start with an hourglass on the shift registers. Look what a beautiful design in a two-board stack! The top board has only the LEDs, and the bottom has all the chips and other components. Any digital circuit starts with a clock. Instead of the apparent 555 timer solution, the circuit designers used the CD4069. It contains six logic inverters, of which only two are used, and the other four are idle. The generator works as follows. There is almost no current through the U1 pin 1 and 3 because they are high-impedance inputs, almost like an operational amplifier. To make input 1 even more high-impedance and thus negate the effect of its current, the developers added a resistor R31. The time-setting circuit, consisting of capacitor C1, resistor R32, and trimmer VR1, is constantly overcharged. Because it is connect

  When servicing metal cable lines, measuring bridges are most commonly used. However, other devices are also available for locating cable faults. Firstly, they provide high accuracy in a wide range of measured values. Secondly, their use makes it possible to organize measurements in such a way as to compensate for extraneous influences, which is indispensable for fault location. Thirdly, they are not expensive. It will be helpful for the reader to become familiar not only with the construction of measuring bridges but also with the principles of their application for fault location. However, speaking the language of mathematics, such knowledge is necessary, but more is needed for constructing optimal measurement schemes. Diagnostics is always both an experience and an art. Pic. 1 The connection of a bridge circuit The principle of the bridge measuring circuit is shown in Pic. 1, and its application in practice is shown in Pic. 2. Resistance R1 is calculated based on the ratio R4/R3 ob

  Nowadays, electronic DIY projects with microcontrollers, especially Arduino, are very popular. The microcontroller makes it easy to create many interesting and useful things. I am even more interested in assembling different devices with simple logic circuits. They are easier to buy when there is a shortage of semiconductors, and they are not susceptible to software failures, hacking, and firmware corruption. And most importantly, their principle of operation is more visual, which gives me aesthetic pleasure. Today I will introduce readers to four simple devices. Three of them are based on flip-flops, and the fourth one, which we will start with, could use a flip-flop. Voting machine The majority rule applies when people vote to accept or reject a proposal. The decision is made if more than half of the participants vote in favor. If there are three voting participants, it requires two or all three to press the buttons to answer in the affirmative. This is the logic of this little ele