From: Joerg Hansmann (info_at_jhansmann.de)
Date: 2001-12-06 16:47:37
Hi,
----- Original Message -----
From: Doug Sutherland <wearable_at_earthlink.net>
To: <buildcheapeeg_at_yahoogroups.com>
Sent: Wednesday, December 05, 2001 5:13 PM
Subject: Re: [buildcheapeeg] a question to serious people , including doug ,jim-p, jim-m and others
...
>
> Joerg: are your prototypes running off batteries?
No. They are powered with DCDC-converters (for isolation)
from the PC (5V gameport)
or fram an external AC/DC-powersupply.
> Is
> battery power mandatory
That depends on the isolation voltage that is required.
I have absolutely no idea if the current modularEEG
isolation voltage is sufficient to get e.g. a FDA approval.
If IEC601-1 must be met the TMA0505 DCDC converter
can not be used and must be replaced with better ones or
batteries.
> or is AC/DC an option?
If we want to meet IEC601-1 at least partially,
and use an AC/DC source it would have to meet
very high isolation demands. (medical AC/DC-source)
> Do we
> need to charge batteries instead of applying the
> AC/DC source directly to the circuits? If it needs
> to run on batteries than I think nicad rechargeable
> with charge circuit onboard makes sense. The ICs for
> nicad are not very expensive.
IMO on board battery chargers could easily corrupt isolation and
are therefore dangerous.
Regards,
Joerg
This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:33 BST