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
Sure, we can agree to disagree. But, you are very misguided. There's no difference in determining the output impedance of a converter or a battery. You need to take 4 measurements. Output resistance is:
Resistance = V1 - V2 / I1 - I2
Where I1 & I2 are different current levels. V1 corresponds to voltage at I1.
You must make differential measurements. Calculating R = V1/I1 is wrong. What's the battery resistance when it is providing 10A at 12.5V, and 11A at 12.55A?
By your method, it would be R = 12.5V / 10A = 1.2 ohm!!!
That's absurd. Given the data, the resistance is 50 m ohm.
The output resistance of very type of voltage source (batteries, converters, power supplies, etc) is calculated using differential measurements. This is elementary electronics!
Sal
Resistance = V1 - V2 / I1 - I2
Where I1 & I2 are different current levels. V1 corresponds to voltage at I1.
You must make differential measurements. Calculating R = V1/I1 is wrong. What's the battery resistance when it is providing 10A at 12.5V, and 11A at 12.55A?
By your method, it would be R = 12.5V / 10A = 1.2 ohm!!!
That's absurd. Given the data, the resistance is 50 m ohm.
The output resistance of very type of voltage source (batteries, converters, power supplies, etc) is calculated using differential measurements. This is elementary electronics!
Sal
DryCamper11 wrote:
We'll have to agree to disagree. We disagree because we're talking about different things. You're talking about feedback theory, which involves changing voltages, while I'm talking about steady state conditions. You are right that the load impedance differs under non-steady state conditions. I thought I mentioned that in my post. It's just that I think the feedback is likely to converge to the steady state quickly under any reasonable battery impedance. AFAICT, the PD is designed according to the recommendations for the UC3846 Unitrode chip.
