Superpower compared to SuperTeddyReg
How does Belleson Superpower compare with a SuperTeddyReg regulator? We compare to the voltage regulator shown here, called the SuperTeddyReg regulator. Both devices were tested with as nearly identical conditions as possible, with both devices using the same input supply and Vout nominally = 24V for both regulators (STR was 23.5V with the R2 and R3 shown below).
First, as advertised, SuperTeddyReg has excellent noise performance. However, it may be better classified as a low noise voltage reference than as a voltage regulator. A performance comparison using both LTSpice and a breadboard shows that Vout varies with load. A measurement at 700mA (see photo below) shows almost 1V change in Vout, or load regulation = 28dB. Said another way, a 700mA change in Iout results in a 4% change in Vout.
Simulation also shows that ripple increases with load, going from 22µV with a 2.4mA load to 520µV with a 602mA load. For the same conditions (Vin=30V, Vripple=1Vp-p sine wave @ 120Hz), Superpower has essentially unmeasurable ripple at 2.4mA and 5µV at 605mA.
The SuperTeddyReg built and measured (shown below) uses different JFETs and
small signal NPNs from the original schematic.
The components do not change the primary behavior of the SuperTeddyReg,
which is governed by the an
open loop topology with no feedback to keep Vout constant with load
Dynamic performance was tested with a 700mA current step for both a
Superpower device and the SuperTeddyReg circuit. Notice C7, which was
added to prevent a low level oscillation. The test circuit was built in
a fastidious way on ground plane. The web site states that the circuit
"allows a maximum current of around 2.5A" so 700mA should not overtax it.
Superpower delivering 700mA into 10Ω. The bottom trace shows voltage measured across a 10Ω load resistor that is switched to Vout, about a 7V step (700mA). Top trace shows Vout to ground as current steps from 80mA to 700mA. The scales are the same as the SuperTeddyReg to the right. Notice Vout (top) has a tiny transient but is essentially flat, what we call "regulated."
Here is the same test, only the vertical scale of the top trace has been magnified to 5mV per division. Here you can see the true regulation ability of Superpower compared to SuperTeddyReg. While the Teddy moves about 1V for a 700mA step, the Belleson regulator moves about 7mV, which is the result of 10mΩ (yes, ten milli Ohms) in the measurement path.
SuperTeddyReg regulator delivering 700mA into 10Ω. Bottom trace shows Vout across a 10Ω resistor. Top trace shows Vout to ground, which ideally should be a flat line at 23.5Vdc. However, notice the 1V per division scale of the top trace, showing that Vout changes almost 1V when the load is applied. This change is a DC shift, not a dynamic effect, due to the lack of feedback in SuperTeddyReg.
A simulation of the SuperTeddyReg circuit shown above confirms that a regulator with no feedback does not regulate. It shows 1.2V of change in Vout with a 700mA change of output current. No amount of fluffy marketing words will make the measurements change.