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Design Makes Handy Audible Tracer - 01/09/03 EDN Design Ideas: The circuit tracer in Figure 1 is a handy tool for finding connectivity paths on a pc board. Because the sense voltage you use to measure the path is lower than a transistor's VBE voltage, you can use the design in circuits containing semiconductor elements without affecting the measurement. The tracer's output takes the form of audio tones Design by Jerry O'Keefe, Cupertino, CA Detect wire breaks with unusual CMOS
gate - 02/10/14 EDN Design Ideas: TDR in the shop? Try this circuit to detect a wire break. 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. Design by Raju Baddi
Evolved-Analysis Technique Provides Greater Insight - 12/05/96 EDN Design Ideas: Circuit-analysis techniques often fail to provide true insight into network design. A previous EDN article (Reference 1) introduced the Extra Element Theorem (EET) and gave designers a powerful circuit-analysis technique that provide as useful symbolic results. The article highlighted EET specialized to an impedance function and applied it to a bridge circuit with a voltage-dependent current source, but the article stopped short of explaining why the method works. Design by Celestino A Corral, Scientific-Atlanta Inc
Fleapower Detects shorts - 07/02/98 EDN Design Ideas: (FILE
has several circuits, please scroll to find this one) Sometimes, the need arises for a short-circuit tester that supplies a low current to the device under test (DUT) and also uses voltages lower than 100 mV to prevent conduction of semiconductors. The circuit in Figure 1 meets these requirements. R1 limits the current in the DUT to 0.9 mA. The voltage on the DUT can not exceed the value set by the ratio R2/ (R1+R2). The NE5230 micropower op amp compares the voltage on RX (representing the DUT) with the voltage at the junction of R3 and R4. Design by W Dijkstra, Waalre, The Netherlands
Fox & Hound Wire Tracer - The "Fox" and "Hound, " made by Triplett Corporation (www. triplett. com) , are a transmitter and receiver for tracing telephone (and others) wires through walls. You connect the transmitter to the wire, and the receiver helps you trace the wire from several inches distance away. Triplett doesn't say much about how they work, but th Fox and Hound apparently use inductive coupling of a low-frequency signal, maybe around 50 to 100KHz __ Designed by Tony van Roon VA3AVR
Hot-Swap Structure Offers Improved Redundancy - 01/09/03 EDN Design Ideas: For redundancy purposes, a number of power supplies, using ORing diodes, can work into the same load. During maintenance, when you can remove any power supply, the minimum possible power perturbation at the load is desirable. To compensate for the voltage drop across the ORing diodes, you must connect the power-supply feedback lines after the diodes, at the load Design by Samuel Kerem, Corvus Corp, Columbia, MD
Induction receiver for tracing wiring behind walls, hearing lightning & other electric discharges - The induction receiver shown below is very sensitive and can serve a variety of purposes. it is excellent for tracing wiring behind walls, receiving audio from an induction transmitter, hearing lightning and other electric discharges, and __ Contact: Charles Wenzel of Wenzel Associates, Inc.
INSIDER V10 - in-Circuit debugger, created by E. E. Atanasios Melimopoulos. Updated Ver 1r1 __ Designed by Jose Pino
Milliohm Squawker great at finding shorts & reverse engineering PCBs - 05/23/14 EDN Design Ideas: This well thought out tool for “listening to” low resistances really speeds troubleshooting & tracing. Design by Glen Chenier
Quickly find PC-Board shorts with low-cost tracer technique - 25-Nov-04 EDN Design Ideas: A predominant failure mechanism for production pc boards is shorted traces. Finding hidden shorts is often time-consuming and frustrating. Typical techniques of cutting traces, lifting pads, and "blowing" shorts are, at best, questionable because they may affect the reliability of the circuit, and the ever-decreasing geometries and lower voltage ICs make these practices tricky and risky Design by Teno P Cipri, Engineering Expressions Consulting
Scheme Detects shorts - 07/08/99 EDN Design Ideas: NOTE: File contains multiple circuits. Scroll to find this one. When you manually assemble complex boards, it’s common to short-circuit adjacent component or IC pins. Determining which section of the circuit you have shorted is not too difficult, but finding the precise point where the short exists can be a formidable task, because the short may be under a surface-mount component. Design by Luis Miguel Brugarolas, SIRE, Madrid, Spain
Short tracer/finder uses low power - 9/07/2014-EDN Design Ideas: Build this bench tool and become a master at pinpointing shorts. Design by Dan Meeks
Short-Circuit Finder uses Few Parts - 11/05/98 EDN Design Ideas: (File contains several ciruits. Scroll to find this one) The simple tester in Figure 1 detects short circuits on assembled pc boards and also rings out cables and harnesses. The short finder has a narrow zone of threshold uncertainty and very low "insertion" voltage and current, and it's not confused by capacitors. The circuit uses an LM10, an IC that combines a precision 200-mV reference, Design by Boris Khaykin, Candid Logic Inc, Madison Heights, WI
Signal Injector / Tracer - A simple test circuit to fault find audio and radio equipment. Can be used to inject a square wave signal, rich in harmonics, or used with headphones as an audio tracer. __ Designed by Andy Collison
Simple Circuit Scheme Detects shorts - 07/08/99 EDN Design Ideas: NOTE: File contains multiple circuits. Scroll to find this one. When you manually assemble complex boards, it’s common to short-circuit adjacent component or IC pins. Determining which section of the circuit you have shorted is not too difficult, but finding the precise point where the short exists can be a formidable task, because the short may be under a surface-mount component. Design by Luis Miguel Brugarolas, SIRE, Madrid, Spain
Test VCOM Drivers - 11-Nov-04 EDN Design Ideas: Flat-panel LCD monitors offer excellent image quality andcompact form factor than CRTs—hence, their steadily increasing popularity. Unfortunately, the complexity of their manufacturing process makes LCD monitors considerablyexpensive than CRTs. The amplifier that drives VCOM, the voltage on the backplane of the LCD panel, must be able to drive large capacitive loads, deliver h Design by Soufiane Bendaoud, Analog Devices, San Jose, CA |
