Evans
Sent: 29 December 2013 03:46
To: volt-nuts@febo.com
Subject: Re: [volt-nuts] Fluke 845 Modification LTC2057
John,
I looked at the LTC2057 but it doesn't go down to 3V operation (4.75 V min)
and I want to power the Fluke 845 with 3V lithiums. In addition, the
LTC2054 has a lower input bias
-nuts@febo.com
Subject: Re: [volt-nuts] Fluke 845 Modification LTC2057
John,
I looked at the LTC2057 but it doesn't go down to 3V operation (4.75 V min)
and I want to power the Fluke 845 with 3V lithiums. In addition, the
LTC2054 has a lower input bias current (1 pA at 25 C). I wanted the lower
Randy,
Most lithium cells (probably all, but I do not know that for a fact) do not
like float charging. When overcharged, they may explode in a nasty way. Also
you do not want to charge multiple cells in series without a balancing circuit.
If you plan on using lithium batteries, make sure you
On 12/28/2013 6:54 PM, Randy Evans wrote:
I am in the process of designing an upgrade for a Fluke 845 Null meter to
eliminate the opto-chopper, which doesn't work in most units today. I am
planning on using the Linear Tech LTC2054 zero drift op amp and power it with
two 3V lithium batteries
John,
I looked at the LTC2057 but it doesn't go down to 3V operation (4.75 V min) and
I want to power the Fluke 845 with 3V lithiums. In addition, the LTC2054 has a
lower input bias current (1 pA at 25 C). I wanted the lower bias current since
I want to use the circuit to upgrade an HP-419A
