High Impedance VS Low Impedance Power supplies?

What power supplies are High Impedance?

What power supplies are Low Impedance?


A High Impedance power supply creates a voltage drop, but what makes a power supply high impedance? or low impedance?

Batteries have impedance, how do you find out the batteries impedance?

Ideal voltage supplies by definition have zero internal impedance.
Ideal Current supplies by definition have infinite internal impedance.
The internal resistance of a battery can be calculated by measuring the voltage at no charge and the voltage drop when loaded with a suitable resistor. It only requires to apply the ohms law. Just consider the battery as an ideal voltage supply in series with a resistor. With no load the voltage drop in this "internal resistor" will be zero.
A regulated voltage power supply will try to keep a constant voltage with different loads (within practical limits) if you apply the method above you will calculate a very small "internal" resistance.
Similarly a constant current supply will vary the voltage to keep constant the current with different loads so the internal resistance will appear to be very high. You can think a constant current source as a high voltage ideal supply in series with a large resistor. Using load resistors that are much less than the "internal" resistor the current will will remain practically constant.

which power supplys are low impedance?
which power supplys are high impedance?