Structure - Bosch L 309 Series Technical Information

1.

Structure

1070 078 131-104 (00.05) GB
Power Supply Module
Type L 309
The L 309 power supply modules serve to operate a welding transformer with max.
150 kVA or 250 kVA. Three types are available, L 309.150, L 309.151 and
L 309.250 with different mains voltages and power data (see Section 2., "Technical
Data").
The L 309 power supply module contains the firing component as well as the thyris-
tor power supply for triggering the welding transformer. The firing component is
triggered by the weld timer. It transmits firing pulses to the thyristor power supply.
The integrated power supply unit generates the 27 V A.C. and 24 V D.C. synchro-
nization voltage for the weld timer.
The primary voltage of the welding transformer is measured and transmitted to the
weld timer for evaluation and control (UPR).
If the welding transformer or the thyristor power supply is overloaded, a thermo-
static switch is released, thus stopping the weld timer which will output a fault mes-
sage.
L1
L2
L1*
L 309
Power
Supply
Module
mains transformer
~
=
24 V D.C.
Block diagram: L 309 Power Supply Module
L2
power supply
firing trans-
former
UPR1 UPR2
27 V A.C. Firing
5 kHz
Weld timer
Structure
Welding transformer
V
measuring
transformer
27 V A.C.
feedback
Temperature
message
1