Chris Elston Posted December 30, 2003 Report Posted December 30, 2003 I was looking for a tester I can connect to my PLc that can test a capacitor and a resistor at the same time and give me a pass or fail signal back to the PLC. Can anyone recommend a tester they have used? Like a HP or BK tester? Quote
panic mode Posted December 31, 2003 Report Posted December 31, 2003 what range and precision? any other particular requirements? (just curious...). Quote
Chris Elston Posted January 2, 2004 Author Report Posted January 2, 2004 About 10% tolerance just as in normal 1/4 watt resisitors and I am not sure on the capacitor, but it's very small. Quote
panic mode Posted January 2, 2004 Report Posted January 2, 2004 (edited) For resistors I was using SLC500 with analog input card. Very simple circuit (only three resistors) was wired to regular 24VDC power supply that was used by the whole machine and two analog inputs of the card. With a little bit of math I got my PLC version of autoranging Ohm-meter that was operating in 0-20MOhm with excellent results (less than 1% error when compared to a good Fluke but this might vary slightly if using different setup). The first choice was RTD transmitter but all of them operate in narrower range (usually less than 10kOhm) so I was forced to come up with something on my own. Let me know if you want it... Btw. Never needed to measure capacitance using PLC. Edited January 2, 2004 by panic mode Quote
Guest Guest Posted January 3, 2004 Report Posted January 3, 2004 It correct, panic mode. If not required, advance solution make it solution: Measure time for max Voltage and end time, it fix resistor or measure tax rate voltage it sample time. I guarantee that functions, I initiated the formation in tecnic of electronics, exists CI (chip) capable of perform lineal from the conversion of curve and guarantee accuracy, permanent persons in the of eletronica I have to help. (One problem CI low voltage adaptation high voltage scale, increases not lineal, sometime one fix scale correction error matematics for PLC) Find more info words: RC , capacitance, time, measure... See page details http://www.tpub.com/neets/book2/3d.htm Quote
Chris Elston Posted January 6, 2004 Author Report Posted January 6, 2004 Thanks for the information guys! Quote
shooter Posted January 6, 2004 Report Posted January 6, 2004 use a very simple 555 timer and you will get a nice time puls out of it. works in big variety of resistors and capacitors. watch maximum voltage of capacitor please. the output of the 55 is put direct into plc which will give a pulstime. and you can make a very fast good/bad out of it. it is the most used ic ever. Quote
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