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DCC Multi-meters ;

Started by Jhanecker2, February 24, 2017, 09:17:41 AM

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Jhanecker2

Does anyone  make  a multi-meter capable of reading  DCC electrical  information  directly  ?  John2. 

Len

You either need a True RMS Multimeter ($350.00+) or one of these things:
http://www.traintekllc.com/rrampmeter-v1-digital-meter-for-dcc-dc-ac-3-rail/?gclid=CJPy-aD_qNICFUEvgQods6MJ-A

You can use a regular multimeter set for AC, but it will read voltage slightly low because of the squarewave nature of the DCC signal. For general purposes, just check the voltage near the feeder closest to your base station. Use that as a base line when checking for voltage drops around the layout.

Len
If at first you don't succeed, throw it in the spare parts box.

dutchbuilder

#2
Or an oscilloscope. (scope) but that is for experienced users.

Ton

Hunt

Quote from: Len on February 24, 2017, 10:05:07 AM
You either need a True RMS Multimeter ($350.00+) or one of these things:
http://www.traintekllc.com/rrampmeter-v1-digital-meter-for-dcc-dc-ac-3-rail/?gclid=CJPy-aD_qNICFUEvgQods6MJ-A

You can use a regular multimeter set for AC, but it will read voltage slightly low because of the squarewave nature of the DCC signal. For general purposes, just check the voltage near the feeder closest to your base station. Use that as a base line when checking for voltage drops around the layout.

Len




A regular multimeter set for AC will read DCC voltage about 7-10% higher than it is because of the PWM square waveform of DCC.


Hunt

Quote from: Hunt on February 25, 2017, 02:57:17 PM


A regular multimeter set for AC will read DCC voltage about 7-10% higher than it is because of the PWM square waveform of DCC.



Clarification

A regular inexpensive (non RMS) multimeter set for AC may read DCC voltage about 7-10% higher than a true RMS multimeter. True RMS multimeter will read the DCC voltage lower than it actually is.




Model railroad use I use a Harbor Freight CEN-TECH 7 Function Multi-Tester far more than I use my Extech 430 true RMS multimeter. The CEN-TECH was free with coupon. (I have several of them)





Hunt

Off topic ---
Not generally known  ----  the inexpensive Harbor Freight CEN-TECH 7 Function Multi-Tester Item 90899 can be user calibrated. Online videos demo the procedure.