7. Power supply
7. POWER SUPPLY
Power can be supplied to the instrument in any of the following ways :
Rechargeable battery pack,
NiMH 7.2 volts / 1600 mAh, internal or supplementary ZB 2890-AP
Mains adapter / charge adapter, 12 volts, 2 A
ZB1112-NA10
Power supply cable (10-30 volts DC, 1 A), electr. isol.
ZB 2590-UK
Our product line includes corresponding accessories.
7.1 Rechargeable battery operation
and supply voltage monitoring
The standard power supply used for this device is a rechargeable battery pack
with 6 NiMH cells (7.2 volts / 1600 mAh). At a current consumption of approx.
37 mA this will operate for approx. 43 hours. If the lighting is switched on con-
tinuously the operating time drops to approx. 16 to 32 hours (depending on
brightness). To prolong the operating time for the purposes of long-term
recording the device can be left in SLEEP mode. (see 10.2.5). The operating
voltage can be checked in the “
power supply
” menu; this gives you a basis for
estimating the remaining operating time. (see 10.7). As soon as the remaining
battery capacity drops to approx. 10% the
´´µµµµµµµµµ¶
symbol in the status line of the
display starts to flash. As and when this happens the battery should be
recharged using the mains adapter provided (12 volts, 2 A) (ZB1112-NA10);
delay may result in critically low discharge and damage the battery. (see 6.2).
The NiMH rechargeable batteries can in fact be recharged at any time and in
any charge status using the intelligent charge circuitry. If the batteries are com-
pletely discharged, the device will switch off but measured data and the time-
of-day will be maintained in the battery-buffered memory. (see 6.6) To continue
operation without having to wait you can replace the discharged battery with a
supplementary battery pack (ZB 2590-AP).
When replacing the rechargeable battery pack ensure that type ZB
2890-AP with Ntc is used; the predecessor model of the recharge-
able battery packs ZB 2590-AP will not function on this device.
7.2 Mains Operation
To supply the device with power from an external source or to recharge the
batteries the mains adapter provided (12 volts / 2 A) (ZB1112-NA10) must be
connected at socket DC (5). Please ensure the mains voltage is correct !
When the mains adapter is plugged in the green “
CHARGE
” LED lights up indi-
cating that the batteries are being recharged. After approx. 2.5 hours the bat-
teries are recharged and the LED goes out again; i.e. the charge circuitry has
switched over to trickle charge. The mains adapter can thus be left perma-
nently connected to the measuring instrument in buffer mode without risk of
overcharging the batteries.
16 ALMEMO
®
2890-9