K7IQ

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K7IQ

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  • 10.26.2017
  • Bang-bang photovoltaic regulator needs no magnetics
  • This method, when used for battery charging has been used for decades. Long time. They are called PWM charge controllers vs. MPPT charge controllers that can take a much higher nominal PV input voltage above battery voltage and efficiently convert down (buck) One thing that method uses is that when the output voltage (battery V) is below its set-point, the switch is on 100% of the time until it reaches that setpoint V (Absorb, Float, etc.) Then, it PWMs to keep the Vbatt constant. These are typically MUCH slower than this circuit, or a few hundred Hz at most. Better for EMI and some have low EMI modes that switch even slower if in that mode. Another reason this circuit, and PWM charge controllers aren't too bad on heat generation is that the nominal PV solar panel voltage is JUST above the highest battery voltage needed. I'm sure this circuit would be similar. You wouldn't use a solar panel with an MPP voltage of 50 volts to charge a 12V battery. Now THAT would be very inefficient. 12 volt PV modules Max Power Point voltages are more like 17 volts at 25 degrees C.
  • 10.10.2012
  • Why can't good engineers get good jobs?
  • I wish there was a web site where engineers and techs could post their resume and employers could download and read as many of them as they want to. Lots of jobs listings but hardly any sites that show resumes' without the engineer seeker spending hundreds if not thousands of dollars ! No wonder ! November ! PS... I also find it next to impossible to find good engineers ! Hardly any applications even given to us in the alternative energy/power electronics industry up here near Seattle.
  • 02.15.2011
  • Not just blowing smoke
  • Back when we were making hi-fi power amplifiers, we would attach a 1/4 Watt resistor across the load resistor on the back of the work bench and then a firecracker fuse to that. That combination would really create a nice surprise !! boB
  • 11.23.2010
  • Analog Devices claims MEMS patent win
  • I have thought that the US Patent system has been broken for many years now and is just an easy way for the US to make money and does not have to be involved in any court litigation. Seems like patents are just useful as scare tactics anymore. boB