Bosch FWA 43 Series - Conductor Board Charging Electronics

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Measuring element | FWA 43xx / FWA 44xx | 23
Robert Bosch GmbH 1 690 326 006 2008-8-25
en
Conductor board charging 11.2
electronics
Ca. 8 VDC – 8.05 VDC rest on the charging socket R
without load (without inserted MWA).
Under the load of 4 inserted MWA, battery new and
R
charged, then the charging voltage falls down to ca. 7 V.
Under the load of 4 inserted MWA, battery new and
R
charged, then the charging voltage falls down to 6.6 V.
Charging electronic board radio / functional diagramFig. 28:
Function11.2.1
The battery charging electronics is supplied with (+ 8 VDC) R
only by the charging contacts.
If the board rests on the voltage then the relay falls
R
down and battery is charged.
If the MWA in radio module is taken in operation then
R
the relay converts and the measuring processor is
operated with battery voltage.
A charging process over "Night" is sufficient for
R
approx. 10 hours operation. The durability of the
battery consists of approx. 5 years.
In mode emergency cabel (radio-MWA with cable) is
i
no battery charging.
Connector pin assignmentFig. 29:
1 Connection battery
2 Connection to measuring processor
3 Connection to the charging contacts
4 Breaking point ST 5
5 Breaking point ST 6
6 Potentiometer P1
Verify and set charging voltage11.2.2
In case of insufficient discharging time of the battery,
the battery charging electronics is to be verified before
the exchange.
Aids
Digital multimeter with 4 digit display
R
Thermometer, accuracy <= 1°C R
Procedure
Open left side of measuring element.1.
Produce charging status, e.g. connect in cupboard.2.
Remove battery cable from battery charging electronics 3.
(Fig 29.1).
Measure voltage over breaking point ST5 and ST6.4.
Balance with potentiometer P1 (Fig 29.6) according 5.
to the table values at room temperature.