Simple 6 Digit 40MHz Frequency Counter Module:  Here is the design for a very low cost 6-digit frequency counter module using of the shelf components (and not that expensive 74C926!). The standard circuit will display directly in Hz (1MHz max), and there is a separate on board divider that will allow you to display directly in KHz (approx 40MHz max). Because the display reads directly in Hz or KHz there is no need for decimal point switching and the associated complexity. There are no switches or controls, simply feed the signal into one of two inputs and you have a direct readout in Hz or KHz. This circuit is ideal for adding a low cost frequency display to a function generator or other design. I doubt if it is possible to get a cheaper design using off the shelf components!. In fact, I challenge anyone to make a cheaper design using garden variety components!....  (add 11/05)

Simple BER meter is easy to Build:  03/02/00 EDN-Design Ideas / (added 7/03) A bit-error-rate (BER) tester is a basic tool for digital-communications measurements. Although many commercial BER testers are available, you can easily design and build an inexpensive version. The scheme in Figure 1 has performance similar to that of a...

Simple car battery tester:  This circuit uses the popular and easy to find LM3914 IC. This IC is very simple to drive, needs no voltage regulators (it has a built in voltage regulator) and can be powered from almost every.... (added 05/07)

Simple Choc Block Supply:  A very simple adjustable power supply can be built on a single piece of chocolate block based on the L200CV IC. The output is variable between 0 and 30V, with an adjustable current limit up to 2 amps. (added 10/06)

Simple circuit detects dc ringing:  08/17/00 EDN-Design Ideas  / (added 2/06)    

Simple Circuit Detects Loss of 4-20 mA Signal:  National Semiconductor Application Note   (app note added 2/06)

Simple circuit provides high side Current sensing:  04/24/97 EDN-Design Ideas / (added 8/03)

Simple circuit Serves as milliohm meter:  04/15/04 EDN Design Ideas  /  (added 1/05)  When I was recently debugging a design, I discovered that a short circuit existed from a ground plane to a power plane. I did not have access to a milliohm meter or an equivalent tester for locating this type of short circuit. So, I logged onto the Internet to find an easily constructible milliohm meter....

Simple emulator speeds testing:  09/25/03 EDN Design Ideas  /  (added 1/05)  Designing and testing embedded hardware can be frustrating if you have to rely on somebody else's perhaps-unready firmware to test your hardware. Often, hardware is ready for testing before debugging and system firm-ware are available from software developers. Microprocessor emulators are solutions but are often expensive, hard to use, and sometimes inappropriate for use by hardware developers,......

Simple ESD gun tests IC:  09/12/96 EDN-Design Ideas  /  (added 2/06)   You can use the simple ESD-test gun in Figure 1 to test the effects of ESD through sensitive ICs. A piezo-electric type kitchen gas lighter (the so-called ESD gun) is an excellent fast-static-charge generator. This gun can cause ESD through air and also through conducting and semiconducting materials. These devices also meet home-use safety standards. To build the device, extend the main pin of the gun so that this pin nearly reaches the test pin of the IC. This distance can be as close as 2.5 mm to form a trigger gap. To fire an ESD pulse directed toward the test pin, just squeeze the gun handle, and a fine flash appears at the test pin of the IC. The amount of charge is about 0.2 µC, and the pulse duration varies from 100 nsec to 1 µsec....

Simple Field Strength Meter:  (electronic circuit added 1/05)

Simple Logic Probe uses Bicolor LED:  03/13/98 EDN-Design Ideas  / (added 03/03)   

Simple MIDI Tester:  (circuit / schematic design added 6/06)

Simple nitrogen spark generator:  (circuit / schematic added 6/05)

Simple Phase Meter operates to 10 MHz:  07)/04/96 EDN-Design Ideas / (added 6/06)

Simple polarity detector:  This tester can be used to check the polarity of any power source, and is therefore very useful when installing automotive equipment, alarm systems or anything else you can think of. Because this circuit is so simple and cheap, even frying one with an over voltage is not a big deal.... (added 4/05)

Simple procedure tests transducer:  03/01/96 EDN-Design Ideas / (added 2/06) 

Simple Remote control Tester:  (electronic circuit added 10/05)

Simple RF Power Meter:  simple RF power meter cum dummy load for low power transmitters. . (added 9/04)

Simple scheme detects shorts:  07)/08/99 EDN Design Ideas  / (added 2/06)  [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. The circuit in Figure 1 eases the diagnosis. It uses off-the-shelf components, and you can build it in a few minutes. The circuit uses a DMM set at its maximum voltage-sensitivity scale (typically, 200 mV full-scale with 0.1-mV resolution). The DMM measures the voltage drop in the divider comprising the 5W resistor and the cable and short-circuit resistance....

Simple setup tests Bit error rate:  03/18/04 EDN Design Ideas  / (added 11/05)  Traditionally, the reception quality of a digital receiver is expressed in terms of BER (bit-error rate). This figure is the proportion of received bit errors in a given period. Typically, you measure the BER in the lab by applying an RF signal, modulated by a pseudorandom code, to the receiver under test.

Simple Technique Measures Small Capacitance:  09/01/97 EDN-Design Ideas  / (added 3/03)   

Simple tester checks Christmas-tree lights:  12/23/99 EDN-Design Ideas / (added 3/03)

Simple tester checks LCDs:  10/03/02 EDN Design Ideas  /  (added 1/05)  Manufacturers of electronic equipment use LCDs for calculators, watches, mini-videogames, and pagers, for example. In comparison with LED-based displays, which consume power on the order of tens of milliwatts, an LCD consumes only a few microwatts. The LCD thus saves power by a factor of approximately 1000....

Simple Voltmeter Monitors TTL Supplies:  National Semiconductor Application Note   (app note added 2/06)

Simulate signals for telecomm tests :  09/11/98 EDN-Design Ideas  / (added 2/06)