From: Mark Benson (markbenson_at_mac.com)
Date: Thu Oct 16 2003 - 05:30:27 PDT
On Thursday, October 16, 2003, at 12:16PM, suppaman <suppaman_at_softhome.net> wrote:
>>From what I've understood the Newton power supply has circuitry to regulate
>current, a standard AC/DC converter would have not and even a Apple power
>supply (like the powerbook one) could have a different way of regulating the
>current.
My father (bless him) filled me in on Power Supplies. He's a bit good with electronics and knows his stuff (he's built everything from radios to computers to electronic weather loggers).
He Says:
Voltage is the critical part. If that is correct you have a good start. The Current Rating is the maximum that the PSU can output safely (without melting) and should be at least the amount required, if not more. If it is above the rating required the PSU MUST have a Voltage Regulator to stop the voltage increasing under decreased load (Power in Watts being constant and a factor of Voltage and Current). This is where most cheap PSUs fall down, they are not reculated so a 12v 900mA PSU outputs 12v at 900mA load or as much as 20v at around 300mA. The vast majority of electronic computer equipment has a regulated power supply to prevent it being blown up when the load requirement drops.
So there you have it :)
>You should open a newton power supply and have a look to be sure but, hey, if
>you have a newton power supply to open better plug it into the newton.. :-)
Ho Ho. Joke of the week...... :D
I'd have thought, from what my dad said, that a Laptop Power Supply woulkd have to be well regulated s othat when the battery charger stopped charging it didn't blow the mainboard or power board due to the increased voltage resulting from the drop in load.
You guys folling me now?
Sa I said before:
>> The connector is not a major issue, as long as I get the polarity right.
So is anyone willing to divulge this information (2 mins with a multimeter will do it) or am I gonna have to guess ;)
-- Mark Benson http://homepage.mac.com/markbenson -- This is the NewtonTalk list - http://www.newtontalk.net/ for all inquiries List FAQ/Etiquette/Terms: http://www.newtontalk.net/faq.html Official Newton FAQ: http://www.chuma.org/newton/faq/
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