UM0933
Safety and operating instructions
Doc ID 17386 Rev 1
9/16
are generated. On the board there is a jumper marked “aux_supply_selection” that allows
the supply, through a separated external source, of the auxiliary power supply on the board.
When setting the jumper in position 1, the DC supply must be provided by an external DC
source capable of a minimum of 45 V (lower voltages do not assure the functioning of the
VIPer16 section) and a minimum current of at least 50 mA. When setting the jumper
aux_supply_selection to position 2, the DC source to the VIPer16 is directly the high voltage
bus available on the power board.
The possibility to use an independent voltage source, allows the control part to be tested or
to see some waveforms without supplying the power part. It can also be useful to supply the
power part with a lower voltage than the nominal in order to work in safe conditions.
Connect the board to the AC power supply (see
and
).
Use a suitable cable, in terms of insulation and cross section, to be able to conduct the
current from the AC power supply according to the maximum power of the application.
Note:
The control system has a sensing of the output voltage delivered to identify a shortcut
condition during hot start or the welding phase. Supplying the power source with a limited or
out of nominal range voltage value can trigger this protection limiting the duty cycle. See the
circuit description (
) to have information on how to disable this function. Supply
the welding machine board with a sinusoidal supply voltage with amplitude in the range
between 185 Vrms to 265 Vrms, or with a DC voltage between 310 Vdc and 375 Vdc. The
power source must be able to supply the power required by the system, according to the
welding current set.
Note:
Do not supply the system with a voltage value higher than 265 Vrms, there is a risk of
serious damage to the board and to property in this case. Do not supply the system with a
voltage below the minimum allowed, 185 Vrms, the system may not operate properly in this
condition.
Note:
A low voltage supply and maximum output load is the worst working condition for the
system, in this condition good cooling is mandatory.
2.6 STEVAL-ISW001V1
main
description
The STEVAL-ISW001V1 demonstration board, developed by STMicroelectronics, provides
a ready-to-use demonstration solution for the implementation of an MMA welding machine.
The board can be used for demonstration purposes but is not, however, optimized for
industrial use or production machinery.
STMicroelectronics has patented a solution to improve the out-current control of the
machine without the use of a shunt resistor on the output. A simple analog circuit
reconstructs the current on the output using the input peak current on the primary side of the
insulation transformer as the input parameter and the reflected welding voltage on the
output inductor.
The current control also implements certain basic functions for good welding performance.
A hot start function improves the heating phase of the rod, during the initial contact with the
metal piece, which allows an immediate arc firing and a short-circuit time to be obtained.
Short-circuit protection drastically reduces the output current after 2 seconds, in case the
arc extinguishes and the consequent sticking of the welding rod. Thermal protection is also
www.BDTIC.com/ST