Filament Circuit; Principle Of Operation - Siemens MOBILETT XP Troubleshooting Manual

Basic functions

Filament circuit

Principle of operation

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
ms
0-10
10-100
0-100
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
Siemens AG
Medical Solutions
KV
>= 81
>= 81
< 81
SPR8-230.840.01.05.02
11.05
KW
30
25
25
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