AN-162: LM2907 Tachometer/Speed Switch Building Block Applications:  National Semiconductor Application Note   (app note added 2/06)

Bi-Directional Motor Speed Regulator:  02/05/2004  EDN-Design Ideas  In low-noise analog circuits, a high-gain amplifier serves at  input to increase  SNR. The input signal level determines  input-stage gain; low-level signals require  highest gain. It is also standard practice in low-noise analog-signal processing to make  circuit's bandwidth as narrow as possible to pass only  useful input-signal spectrum. Designed by Andrew R. Morris  (added 6/06)

Circuit Measures Diesel's Rotations Per Minute:  03/04/99 EDN-Design Ideas / (added 8/03) You may find it useful to measure a diesel engine's rotations per minute to accurately adjust the idling or to compare the motor's speed under hot and cold conditions, for example. Not all cars or trucks come with a tachometer. The scheme in Figures 1 and 2 allows you to measure rotations per minute with a DMM or an oscilloscope. In Figure 1 , a piezoelectric sensor and an alligator clip, fastened directly to one of the four metal fuel pipes, detect the fuel-injection pulses. The piezo element generates a signal that connects to the signal-conditioning electronics in Figure 2 through a coaxial cable. The circuit uses a charge amplifier.....

Combination Tachometer, Thermometer, and Counter:  Inspired by the need to measure dc motor speed and detect overheating, this 68HC908KX8 microcontroller-based circuit displays various statistics on six-digit, eight-segment, numeric LEDs. See movies of a thermistor in action as well as a reflective or interrupt-based photosensor counting.  (project added 11/06)

Digital Engine/Race Computer Board:  The objective of this project is to design a high speed digital engine tachometer. This requires the design and development of a hardware and software solution to monitor the status of an engine in real time. In addition, information relating to the overall health and systems of the vehicle can be displayed.  (added 10/05)

Lego Mindstorms Double Rotation Sensor:  (circuit / schematic design added 6/06)

LM2907 Tachometer/Speed Switch Building Block Applications:  National Semiconductor Application Note   (app note added 2/06)

Optical Tachometer Provides BiDirectional Info:  05/21/98 EDN-Design Ideas / (added 3/03)  

PC-Based DC Motor Speed Controller:  (circuit / schematic design added 6/06)

Programming the Automatic Fan Speed Control Loop:  AN-613 Analog Devices Application Note   (app note added 6/06)

Simple Circuit Measures Diesel's Rotations Per Minute:  03/04/99 EDN-Design Ideas / (added 8/03) You may find it useful to measure a diesel engine's rotations per minute to accurately adjust the idling or to compare the motor's speed under hot and cold conditions, for example. Not all cars or trucks come with a tachometer. The scheme in Figures 1 and 2 allows you to measure rotations per minute with a DMM or an oscilloscope. In Figure 1 , a piezoelectric sensor and an alligator clip, fastened directly to one of the four metal fuel pipes, detect the fuel-injection pulses. The piezo element generates a signal that connects to the signal-conditioning electronics in Figure 2 through a coaxial cable. The circuit uses a charge amplifier.....

Speed Limit Alarm:  (circuit added 9/04)

Tachometer Demodulator has Fast Response Time:  12/07/95 EDN-Design Ideas / (added 8/03) When a tachometer is a critical part of overspeed-shutdown circuitry, the response time of conventional demodulators may be too long. The circuit in the block diagram in Figure 1 provides updated speed data. The circuit provides corrections for variations in excitation amplitude and frequency at every excitation half-cycle. The circuit is independent of processors and, therefore, immune to softwareand bus-related failures....

Versatile Digital Speedometer uses Few Components:  05/12/05 EDN Design Ideas  / (added 6/06)  Microcontroller, display, and sensor form digital speed readout.

Wireless Auto Tachometer:  (electronic (schematic / circuit added 4/02)