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Article: Use your printer port as a high-current ammeter.(Technology Information)
- Article from:
- EDN
- Article date:
- July 6, 2000
- Author:
CopyrightCOPYRIGHT 2000 Reed Business Information, Inc. (US). This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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WITH A FEW INEXPENSIVE components and INT1Ch, you can turn the printer port of your PC into a high-current ammeter. This design's goal is to make remote high-current measurements, but you can use this technique to remotely measure any other similar analog electrical quantity, such as voltage and charge, at moderate speeds without going for expensive, PC-based general-purpose or tailor-made data-logging add-on cards.
In Figure 1a, a low temperature-coefficient manganin element senses the high current of the remote module. The manganin element gives an output of 0 to 500 mV, which is [V.sub.IN] to the circuit, for an output-current range of 0 to 100A. ...