PD or Iota for my upgrade?
I'm thinking about a converter and battery upgrade. The batteries will be wet cell lead acid 6 volt Possible T-105s or the 230AH, EGC2 from Sam's club. I'll probably go for four. (Does nayone have...
Forum Discussion
DryCamper11 wrote:
When you force DC current through a voltage source with zero impedance, the voltage source looks exactly like a resistor having an impedance equal to the voltage divided by the current you are forcing through it. In the case of 12.2 DCV and 60 amps, that's 203 milliohms. The "ideal" 12.2 DCV voltage source in the model looks like a 0.203 ohm resistor when 60 amps are going through it. Add that to the 37 milliohms of the model and you're at the 240 milliohm level. That's what the converter sees when outputting 60 amps. It can't tell if it's really a 240 milliohm resistive load or a 37 milliohm load in series with a 12.2 volt source unless it changes the current.
That's not how it works. The source impedance is not equal to output voltage divided by current. Source impedance is much lower than your calculated 0.203 ohms. If you studied feedback control theory then you would know the error amplifier located inside the Unitrode chip reduces output resistance by the magnitude of the amp gain. The amp has very high gain. Resistance is quite low; as it should be.
I wish you luck with your PD measurements. Make sure the error amp reference voltage remains constant when there's high current demand. PD's issues probably center around the error amp mechanization.
Sal
