> If I read above correctly, you imply that ADSI phones don't need > wall-warts (A/C power transformers that plug into the wall). I'd assume > that based on the sizable LCD screen, potential back-lighting, > microcontroller(s), etc, that an ADSI phone would have to have a > wall-wart, especially if you wanted to use any of its functionality while > it is on-hook. I have designed a phone or two in my past (many years > ago) and, as I recall, there is almost *no* current available from the > telco while a phone is on-hook. You might be able to trickle-charge a > very small battery, or run an RCA 1802 processor (microamps), but that's > about it.
Actually you are guaranteed a 20mA loop from the telco (and I would imagine from any channel bank as well) -- with CMOS technology you can do a _lot_ with 20mA... Unfortunately backlighting is not one of them, nor is driving a lot of LEDs. :-) And yes, I had not seen the forest for the trees and I ran smack into the middle of one of them. (I have done this in real life too once... the looks people give you...) I take back my statement that the wall-warts are an IP phone-only thing, this is simply not true. And IP phones give you the option of POE, something that you can't do with ADSI phones. Regards, Andrew _______________________________________________ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
