Practical Data Acquisition using a Windows based Power Meter


Posted on Feb 6, 2014    5748

This application note describes the design of a PC-based, 14-bit data acquisition system. It takes a system approach, includes all the necessary building blocks: analog, digital, hardware, and software. It discusses each step, testing systems separately before integrating them, and detailing pitfalls learned along the way. Many articles h


Practical Data Acquisition using a Windows based Power Meter
Click here to download the full size of the above Circuit.

ave been written about the building blocks in a typical data acquisition system, but few address the entire system, from analog input to PC display. To cover all the problems encountered in designing a complete data acquisition system, the engineer might have to amass ten articles. The following application note describes the design of a PC-based, 14-bit data acquisition system. It takes a system approach, includes all the necessary building blocks: analog, digital, hardware, and software. It discusses each step, testing systems separately before integrating them, and detailing pitfalls learned along the way. The need for a power meter is apparent to anyone who has tried measuring the input and output characteristics of a DC-DC converter using conventional instruments. The design allows users to perform load measurements on the device under test without connecting an endless spaghetti-mass of test leads. Figure 1 shows the completed power meter display on a personal computer (PC) monitor. To cater for boost, buck, and linear implementations, the measurement range was chosen as 30V for both input and output. Most quality DC-DC converters operate at 100kHz or higher. The system`s frequency response should therefore be higher than 100kHz, but a slower response is also acceptable because the switching waveforms are reasonably repetitive. The system`s 14-bit resolution was not of prime importance in the design stage, because...




Leave Comment

characters left:

New Circuits

.

 



Top