From very bad experience I can strongly advise you:
BE VERY VERY CAREFUL SELECTING A NON-NEWTON POWER ADAPTOR !!!!!
1st If you connect your Newt to a laboratory power supply with the correct
settings (current limitation to 1.2 Amps, Voltage to 7.5 Volts) you can
easily prove that the Newt will take all he gets: as soon as the battery is
starting to charge in fast mode the power supply switches to constant
current.
Of course after a while when the batteries have got a certaion charge level,
it switches back to constant voltage mode.
2nd Be very careful with what is written on the adaptors. Unregulated
adaptors are very dangerous and offer typically much more output voltage
than specified on a low load - depending on the power capability that would
definitely KILL YOUR NEWT !!!!
If you can get a REGULATED power adaptor rated at 7V or 6V you are on the
safe side without taking care of the current limitation, but in this case
your batteries will need a longer time for charging up. The optimum is with
current limitation to 1.2 Amps and a max. voltage of 7.5 Volts.
Thats the reason I think about a little project building my own adaptor with
constant voltage output and current limitation what you can feed with any dc
supply up to 28 Volts.
Johannes
> On Sunday, September 29, 2002, at 01:14 PM, Peter Cameron wrote:
>
> > AC in 100V-240V, 50-60Hz, 20-38VA
> > DC out 7.5V, 1.2A
> >
> > But, unlike many other AC adapters, the 9W Newton adapter does not
> > allow
> > the output to exceed what the Newton can take when it goes into the
> > fastCharge mode. Other adapters will give the Newton more that the
> > specified
> > power when the Newt asks for it _ not a good thing.
> >
> >
> Do you mean that the Newton would draw more than 1.2A (=9W_at_7.5V) if it
> was available? It seems that as long as you get a power supply that
> won't put out more than 1.2Amps you should be fine. (It seems kind of
> surprising to me that the charger would depend on a current regulator
> in the AC power supply instead of putting it in the device itself...
> Also -- isn't there a temperature sensor in the battery pack? That
> should stop it charging when it starts to overheat)
-- Read the List FAQ/Etiquette: http://www.newtontalk.net/faq.html Read the Newton FAQ: http://www.chuma.org/newton/faq/ This is the NewtonTalk mailing list - http://www.newtontalk.net/
This archive was generated by hypermail 2.1.2 : Thu Oct 31 2002 - 12:02:11 EST