Siemens MOBILETT XP - Filament Circuit; Principle of Operation

Siemens AG SPR8-230.840.01.05.02 MOBILETT XP
11.05 CS SD 24
Basic functions 61
Page 61 of 72
Medical Solutions
Filament circuit 0
Principle of operation 0
The filament circuit controls standby heating, preheating in the preparation phase, and the
tube current during exposure.
The filament circuit is made up of the following components:
- D916 (CPU)
- Filament inverter on D927
- D907 measurement data log
- Filament transformer/heating coil for the single tank
- Intermediate circuit, capacitor bank D972
In standby and during preheating, the primary current of the filament transformer is
obtained from D916 (CPU) ( TP I / D916 (1 V = 1A)). The effective primary current is con-
verted into IH and regulated by the target IHS value (TP IH / D916 (1 V = 2 A)).
During an exposure, D916 (CPU) controls the filament circuit via the tube current.
The exposure is performed with a decreasing load, reduction in the tube current.
Maximum exposure output:
Tab. 2 Maximum output for different exposure times
Possible error messages for the filament circuit:
- ERR 6, filament inverter frequency error
- ERR 7, invalid primary filament current
- ERR 9, invalid tube current, mA <> 0
- ERR 12, short-circuit of the filament inverter
- ERR 15, static short-circuit of the filament inverter
- ERR 22, short-circuit of the filament inverter
- ERR 23, filament current exceeds permissible limit
- ERR 34, tube current exceeds permissible limit
- ERR 36, short-circuit of the filament inverter
- ERR 38, error in the mA control loop
- ERR 42, filament current exceeds permissible limit
ms KV KW
0-10 >= 81 30
10-100 >= 81 25
0-100 < 81 25