[NTLK] "Mobile" power supply for eMate 300

[Avi Drissman]

On Tue, Aug 23, 2022 at 3:29 PM Victor Rehorst <victor at chuma.org> wrote:

> Unfortunately Newton devices are real picky and want input pretty much
> no less than 6V and no more than 8V - see the FAQ:
>
> https://newtonfaq.com/newton-faq-hardware.html#IIB7
>
> USB-PD negotiation uses those fixed voltages, there's no way to
> negotiate something in between - which is a shame.
>

There actually is, it's called USB PD PPS, and it allows the device to dial
in a variable voltage. However, it's very new, and hard to find trigger
boards for it.

For something like 7.5V you could build off of
https://myvolts.com/product/39078/Ripcord_USB_to_7.5V_DC_power_cable_compatible_with_the_Casio_ML-2_Keyboard
. I don't know what the socket on the eMate looks like in dimensions or
polarity, but there's your voltage.


>
> -V
>
> On 2022-08-23 10:07, Avi Drissman wrote:
> > USB C has something called Power Delivery, where a suitably powerful
> charger can deliver up to 240 W with voltages of 5, 9, 15, 20, 28, 36 or
> 48V. That’s how laptops charge over USB C. And since it takes just a little
> negotiation to get those voltages from an adapter capable of sending them,
> you can get cables with the negotiation chips built in.
> ----------------------------------------------------------------------
>
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