Functional Description; Switching Power Supply; Pcb Nc Battery Charge; Charging Circuit For The Nc Battery - GE MAC 1200 Servicing Instructions

GE Medical Systems MAC 1200 V 1.2 Page 11
Information Technologies 227 492 21 Rev F
2 Functional description
The block circuit diagram of the entire instrument in Section 1.1 and the functional blocks of
circuit diagram sheets (P-plans) describe the individual functional blocks.
2.1 Switching power supply
The switching power supply generates the fundamental device voltage for the PCB Control
CS Ci and for the PCB NC Battery Charge.
It has the following input specifications:
Input voltage range: 85 ... 264V ac
Line frequency range: 47 ... 65 Hz
The output voltage is +26.5 V dc, the maximum load is 1.5A.
2.2 PCB NC Battery Charge
MAC 1200 can operate battery powered. With a new, fully charged NC battery, in
Automatic Mode up to 50 ECG can be recorded.
The PCB NC Battery Charge, controls and monitors the charging process, depending on
the status of the battery and the status of the device.
2.2.1 Charging circuit for the NC battery
An integrated charging device is used to charge the battery. During charging it monitors the
battery voltage function and switches over from rapid charging to trickle charging.
Applying the line power to the MAC 1200 , or insertion of the battery activates the charging
circuit.
During a recording, the charging current is reduced.
In standby mode, a depleted battery is fully charged within 4 hours.