apummer945

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apummer945

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  • 02.24.2016
  • If engineers ruled the world…
  • actually you could see how does it work if ingenieurs running a country, just look to China, wherein the last twenty years almost everything step by step became better, since ingenieurs are practical people and they know, that the laws of the nature does not tolerate ideologies
  • 09.16.2010
  • Diesels challenge hybrids for efficiency, low emissions
  • well it is logical, the HEV is clean as long as it is running electrical -- max 50 miles -- after that it is a relatively simple and not extremely efficient gasoline driven car, there was a practical compare: http://www.joewein.net/blog/2008/04/04/toyota-prius-hybrid-versus-bmw-diesel/
  • 08.04.2017
  • Build your own oscilloscope probes for power measurements (part 1)
  • Short the newly created probe's input to it's own ground, and touch any ground with that shorted input probe to any ground of a working -- under power -- power supply, despite the probe input is shorted you will see signal on the scope's screen...The scope's input ground is not on the same "noise potential" as the power-supply's ground, therefore there will be a "noise current" between the two grounds, which will cause a noise voltage between the two end of the probe's cable shield. If you open the short at the end of the probe and using the probe to see voltage wave-forms in the power-supply, that noise voltage will add to the wave form what you observing in the circuit. You could eliminate that problem, if you are using a differential probe, or if you modify your newly created probe with common mode suppression, by using large ferrite sleeves or rings, just pull the probes cable a few times trough a sleeve, more is better. You could test the result by shorting the probe input again and connecting it to the power-supply's ground, you should see much lower or almost nothing on the srceen.
  • 08.15.2016
  • Monolithic JFETs are alive and well
  • these links are broken: here's an app note Bob Cordell did for us that has some of those for the N-Channel counterpart: http://linearsystems.com/assets/media/application_notes/LSK489_Application_Note.pdf. Another one by Ron Quan using the LSK489 for sensor applications: http://linearsystems.com/assets/media/application_notes/Guide_Use_FETS_Sensor_Applications.pdf
  • 04.04.2017
  • Slippin' and a slidin'
  • yes that resistor will prevent the input from floating, but depend on the ratio of the resistor value and the pot-meter value it will modify division ratio and it will constitute one additional load to the signal source. Potentio-meters with sliding wipers were used in old radios as volume control, they wear our caused noise by turning, a drop of thick silicon oil, which sealed the pot-meter made a wonder, the old potentio-meter worked fine again