CMOS devices have large input impedance with input currents on the order of 0.01nA. Adding feedback circuitry can result in a latch-like device that can be used to store bits, and also operate in a more analog mode as shown in this Design Idea, which pinpoints the location of a break in a wire. First let’s look at the use of CMOS gates as memory devices. Figure 1 shows a one-bit transparent latch. A single CD4069 hex inverter can make a 3-bit latch, or if one uses a CD4050 hex buffer one... [+]

In this article we are going to make a Invisible Broken Wire Detector which is used to check broken or disconnected wires inside the walls. It detects the broken wire by detecting the presence of AC voltage in the wire. When there will be AC voltage present near it, then it will start beeping and LED will go high while when there will be no AC voltage or if there will be a broken wire, then the buzzer will remain quiet and the LED will go low. This circuit can also serve as EMF detector and can... [+]

Un detector de cables o traçador de cables, és un dispositiu que s'utilitza per trobar cables ocults en les parets, sota el paviment o sota terra. En ocasions es trenquen els cables i, per reparar-los o canviar-los, cal saber per on passen o a on s'han trencat, sent impossible saber-ho amb un simple examen des de la... [+]

Application: used for maintenance and check for communication cable, electrical power cable, construction pipe and hot project, etc. Especially suitable for finding open or short circuit for cable or metal pipe, fuse or socket or junction box location and so on. Transmitter, built-in AC/DC detecting function, can show transmitting power, code, battery status, detecting voltage value and warning signal. Receiver can scan and check the frequency automatically, also can show the information... [+]