Larry Pina documents the International Analogue board pretty well for those of you interested. There are 4 filter capacitors on it (two extra than the domestic board) in the power transformer circuitry (and a few other minor changes as well). It still seems to me that there would be less heat with less power to step down, possibly bypassing the two extra caps altogether (so 2 less things to generate heat)? Not being an electrical engineer, what you say seems to indicate using 120V would actually generate more heat stepping up from 120V because all the caps would have to maintain a charge to supply the proper 320V DC board voltage, creating a greater strain on the components involved? BTW the original SE was the first fully automatic switching power supply. I have a VERY late model Plus with the domestic board. SO it would seem the only way you would have a manually switchable power supply is if you bought your Mac outside the US. But the "International" board with the voltage jumpers was clearly available from day one. I can't imagine it was actually that much cheaper to design two boards and have them both in production simultaneously than to simply include the extra circuitry and have one design in production only. But that's Apple for ya! FYI, the MacXL had a manually switched power supply standard in all models. The best way to avoid heat, would most likely be to move the power supply out of the case all together and feed in only the DC voltage required. Unfortunately the SE series is the only compact you can do that with (without hacking the analogue board), but then you could probably lose the fan!
> From: Doug McNutt <[EMAIL PROTECTED]> > At 06:41 -0500 6/17/05, Jack Gallemore wrote: >> Does running it at 110v extend the life of circuits? </Possible dumb >> question> > > Probably not. > > In those days the usual input circuit used two filter capacitors and switched > diodes so that they were charged in series for 110 volt operation and in > parallel for 220 volts. Either way the rest of the input circuitry sees 220*SQRT(2) volts DC. That's about 320 V which is why they say no user serviceable parts inside the power converter. -- Compact Macs is sponsored by <http://lowendmac.com/>. Support Low End Mac <http://lowendmac.com/lists/support.html> Compact Macs list info: <http://lowendmac.com/lists/compact.shtml> --> AOL users, remove "mailto:" Send list messages to: <mailto:[email protected]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive:<http://www.mail-archive.com/compact.macs%40mail.maclaunch.com/> --------------------------------------------------------------- iPod Accessories for Less at 1-800-iPOD.COM Fast Delivery, Low Price, Good Deal www.1800ipod.com ---------------------------------------------------------------
