How does Superpower compare to a supply that some consider the best DC source?

Dynamic performance of a 1.8A current step was compared between a Superpower and a 6V battery. The battery is a new carbon zinc dry cell type, one of those big ones that looks like a square brick with 2 springs on top and goes in a flashlight. We also tried four new AA size alkaline batteries in series with virtually the same result.

The measurement was made by supplying Vin to a Superpower device under test (DUT) from a power supply using a Superpower and from a battery. Vin from the power supply was 6.25V and from the battery was 6.5V (it was previously unused). The DUT was a SPJ78 at 5V out. If you didn't peek ahead, take a guess as to which has better current delivery.

Dynamic performance

Superpower, 1.8A pulse

Superpower delivering 1.8A. The bottom trace shows Vout measured across a ½Ω load resistor. Top trace shows Vout to ground. The almost invisible shift at this scale is almost entirely due to contact resistance in the test socket.

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Battery, 1.8A pulse

Battery trying to deliver 1.8A. Bottom trace shows Vout across a ½Ω resistor (1.8A/div). Top trace shows Vout to ground. Notice that Vout is limited by the battery as its internal resistance changes due to (most likely) internal heating. Superpower wins again!

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