_____ ( _ ) | ( ) | | | | | | (_) | (_____)
___ ( _`\ | (_(_) | _) | | (_)
###### # ## ## ## # ######
## ## ## ## ## ## #### ##
__ __ \ \ / / \ V / > < / . \ /_/ \_\
IMPORTANT: enter the case-INsensitive alphabetic (no numbers) code AND WRITE SOME SHORT summary of changes (below) if you are saving changes. (not required for previewing changes). Wiki-spamming is not tolerated, will be removed, so it does NOT even show up in history. Spammers go away now. Visit Preferences to set your user name Summary of change: '''Recording audio frequency signals''' * [http://biphome.spray.se/baxtrom/soliton.htm soliton] * [http://audacity.sourceforge.net/ audacity] seem nice, but it is a cross platform tool and they are often farily unstable. Looks nice though.It has a VERY nice feature, when you press the large record button it will instantly start to record, if you stop and press rec again it will make a new recording in a new window. Perfect for us. ---- '''Signals''' to measure * InputTrigger ** VR ** Hall * knock (see KnockListener) * injector channels * WideBand heater output * wideband nernst signal * ignition ** HV: do not make contact, try to wrap a few turns around the HV insulation. Take extreme care.WhatEverYouDoYouDoItAtYourOwnRisk ** ignition transformer primary: this can kill as well. much bigger voltage division is needed than for 16V signal (eg. 5*470k in series insted of 100k) - be very careful ** logic level ignition signal * supply noise * ground noise ---- '''Hardware''' http://linkopingsmotorsport.se/vrtomic.gif Best HW depends on notebook and the signal to measure. * voltage divider ** R1=100k from signal ** R2=1k to GND * optional: 1..10uF non-polarity (not electrolitic! a cap from GenBoard/VerThree/RescueKit is fine) cap to the soundcard input * cable shield connected on one end only This was sufficient for upto 16V signal (but soundcard mixer settings can tune this). Note that there is a high-pass filter involved (the soundcard cuts freq below 20Hz), so the squarewaves are changed in a predictable way: possible to evaluate waveforms, but takes some getting used to. For us it immediately made temporary loss of injector signal (due to fully pressed TPS or processor reset) visible. Possible to test and tune on the table with mdh commands. Eg. recording output from i259 chip at the IGBT gates and mdh02..72 for signal=low and mdh82..f2 for signal=high - make sure not to fry anything that's accidentally left on output, eg. a coil. http://200sx.jagenheim.se/images/probe.png ---- '''See also''' * ElectronicDesign * ElectronicDesign/TriggerSignalGenerator '''very useful''' * DetonationDetection * DetonationDetection/LogAnalysis Optional: Add document to category: Wiki formatting: * is Bullet list ** Bullet list subentry ... '''Bold''', ---- is horizontal ruler, <code> preformatted text... </code> See wiki editing HELP for tables and other formatting tips and tricks.