> So maybe it could be done with a current/forthcoming consumer USB PD wallwart, without needing to add additional power circuitry? You may need a circuit to n

> So maybe it could be done with a current/forthcoming consumer USB PD wallwart, without needing to add additional power circuitry? You may need a circuit to negotiate the USB-PD, then to ouput 20V from that, but it should be possible. It could even be a very interesting project: expose an artificial resistance on the barrel plug to simulate the Lenovo AC wattage resistor by matching what the USB-PD can deliver.