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Block 27
Block 28
Block 29
Block 30
Block 31
Block 32
Block 33
Block 34
Fan
Torch button
Torch button galvanic separator
Torch powered LED
Air relay
Air solenoid valve
Pilot arc resistance
Pilot arc galvanic separator
Consisting of:V1.
Powered directly by block 11 (flyback transformer) and cools
the power components.
Consisting of: plasma torch.
Pressing the torch button strikes the pilot arc and enables the
air solenoid valve. The signal is re-dimensioned to enable
processing by block 29.
Consisting of: ISO1A.
The signal from block 28 is separated galvanically and sent to
block 22 (plasma cycle control) which will process the
information.
Consisting of: D35 yellow LED.
This lights up under instruction from block 20 (plasma cycle
control) when the torch button is pressed and it indicates that
the cutting circuit is activated.
Consisting of: K2.
This is energised under instruction from block 20 (plasma cycle
control) and activates block 32 (air
Consisting of: solenoid valve.
Supplies the compressed air, to permit pilot arc strike, and is
necessary for torch operation and cooling.
Consisting of: R43 and R44.
Allows the pilot arc to strike for a maximum of 2 seconds.Within
this time the electric arc should have been transferred to the
piece of iron to be cut: if not block 20 (plasma cycle control) will
reset the complete cutting cycle.
Consisting of: ISOD and ISOB.
The signal from block 33 is separated galvanically and sent to
block 20 (plasma cycle control) for correct management of the
plasma cutting cycle.
solenoid valve) when
the torch button is pressed.
TECNICA PLASMA 18 - 31
Block 18
Block 19
Block 20
Block 21
Block 22
Block 23
Block 24
Block 25
Block 26
Current potentiometer
Maximum current adjustment
Plasma cycle control (control board)
Power transformer thermostat
IGBT thermostat
Galvanic separator
Overvoltage safeguard
Undervoltage safeguard
Power supply LED
Consisting of: R42.
This is used to set the reference voltage needed to adjust the
output current: when the potentiometer knob is turned the
cursor voltage varies, thus varying the current from the
minimum to the maximum value.
Consisting of: R32, R33, R42.
Used to adjust the maximum cutting current to be supplied by
the power source.
Logic control board that manages typical timing for the plasma
cutting cycle with the contact torch.
Consisting of: ST2.
When the temperature of the power transformer is too high,
this safeguard is triggered. It is reset automatically after the
alarm condition has ceased.
Consisting of: ST1.
When the temperature on the IGBT dissipator reaches a pre-
set level the thermostat triggers to indicate an alarm to block
23 (galvanic separator). Reset is automatic when the alarm
condition ceases.
Consisting of: ISO1C.
The signal from blocks 21 and 22 (thermostats) is separated
galvanically and sent to block 16 (alarms) for identification of
possible alarm condition.
Consisting of: R3, R4 and part of the control section.
If the main supply voltage exceeds the maximum value this
safeguard triggers (a tolerance of approx. ±15% of the power
supply voltage is allowed: outside this range the safeguard
triggers).
Consisting of: R5, R6 and part of control board.
If the main supply voltage falls below the minimum allowed
value this safeguard triggers (a tolerance of approx. ±15% of
the power supply voltage is allowed: outside this range the
safeguard triggers).
Consisting of: D2.
Indicates when the power source is correctly powered and
ready for use.
