Kludging a 9.5v 22w supply?

[[email protected]]

If you needed to come up with a 9.5 v 22w spare laptop power supply,
how would you do it?

a) Get a compact 9v output switcher and try to rework it for a
slightly higher output voltage?

b) Get a 12 volt unit and add a linear regulator with a big heatsink

c) Get a 12 volt unit and add an additional switching regulator? which
regulator?

This is incidentally for an Asus EeePC, which is an astoundingly
capable, affordable micro laptop that's too new to have any
aftermarket or even manufacturer accessories available. First
machine I've ever seen that's small enough to carry, cheap enough to
risk carrying, and capable of doing real work... ultraportable
terminal, compile code if you must, web browsing... and actually it's
just begging for a stack-under USB scope-a-lyzer add on.

Reportedly, 9 volts is not enough to convince it that an external
supply is present.

 

[Martin Brown]

If you needed to come up with a 9.5 v 22w spare laptop power supply,
how would you do it?

a) Get a compact 9v output switcher and try to rework it for a
slightly higher output voltage?

b) Get a 12 volt unit and add a linear regulator with a big heatsink

c) Get a 12 volt unit and add an additional switching regulator? which
regulator?

Get one of the generic universal switched mode PSUs rated for steps of
1v over a range of 5-24v at eg 70W max output and stick a suitably
rated diode in series to drop 10v to about 9.4v. Why make life
difficult?

Regards,
Martin Brown

 

[[email protected]]

Get one of the generic universal switched mode PSUs rated for steps of
1v over a range of 5-24v at eg 70W max output and stick a suitably
rated diode in series to drop 10v to about 9.4v. Why make life
difficult?

Diode idea had occured to me, but I wasn't finding ready sources of
10v supplies either.

Guess I will have to look harder. Did you have any specific one in
model/source in mind?

 

[[email protected]]

Okay, I'm seeing some from Velleman meeting your description. I do
wonder what the setting element is - resistors? Quite tempting to
change change the set point rather than resort to a diode.