/ terp58oneill's Library/ Notes/ Flashlight Height Control By means of Arc Voltage Sensing for Plasma Cutting
Flashlight Height Control By means of Arc Voltage Sensing for Plasma Cutting
from web site
The role of the torch height command system for mechanized cutting systems will be often understated. Some sort of good THC (Torch Height Control) is completely critical to acquire good cut good quality. It is a known fact that undoubtedly the best possible command technique is by realizing the cutting voltage. The cutting volt quality is directly proportional for the height involving the torch in addition to the workpiece; higher the distance, higher the voltage and vice-versa. So 1 can easily consider the cutting ac electricity as a management parameter and employ the same regarding controlling the stand-off distance. This approach of control is definitely frequently referred to as AVC (arc voltage sensing). Sensing the arc voltage is just not lacking of challenges. Typically the torch is put through a high consistency pilot arc, which usually creates plasma. This kind of HF can effortlessly traverse back in typically the sensitive voltage testing circuitry and damage/cause malfunctioning of the technique. It is absolutely essential to isolate the particular measuring circuitry from the plasma HF yet be able to measure the ac electricity accurately. Highly hypersensitive arc voltage command circuitry can detect voltage variations lower than 0. 5V. Correct measurements as nicely as isolation can be achieved via using Hall devices.
Piercing through heavy metals has a good adverse influence on the particular life of typically the torch consumables. Therefore, piercing needs in order to be carefully managed in order to maximize living involving consumables. An appropriate pointed sequence is discussed below with schematics:
I) Each time a control is received by the CNC to start out cutting, the flashlight height controller actions the torch to touch the workpiece, to ascertain actually zero level. The platter can be sensed through multiple components, most commonly utilized is ohmic sensing / motor rpm sensing / a combination of each. When the plate has been sensed, typically the torch now actions upwards.
ii) The torch continue to be proceed upwards into a developed piercing height. On reaching this height, the plasma arch strikes and the menu begins to get pierced While spear like takes place, a new lot of molten metal (depending for the thickness of typically the plate being pierced) jumps out involving the plate plus forms a pool area. The torch must be protected from this molten metal, and so the torch carries on to move upward to a programmed "molten pool jump" height.
iii) The torch now goes downwards to the particular programmed cutting height. The THC product now provides a transmission to the COMPUTER NUMERICAL CONTROL to start activity
iv) The torch now continues to move exact same reducing height. Arc volts is constantly provided back to the particular control unit, which usually keeps a constant arc voltage through an appropriate PID handle loop.
9-8215 electrode
These discourse amply demonstrates typically the role of the good THC for the very good cut with plasma.
Piercing through heavy metals has a good adverse influence on the particular life of typically the torch consumables. Therefore, piercing needs in order to be carefully managed in order to maximize living involving consumables. An appropriate pointed sequence is discussed below with schematics:
I) Each time a control is received by the CNC to start out cutting, the flashlight height controller actions the torch to touch the workpiece, to ascertain actually zero level. The platter can be sensed through multiple components, most commonly utilized is ohmic sensing / motor rpm sensing / a combination of each. When the plate has been sensed, typically the torch now actions upwards.
ii) The torch continue to be proceed upwards into a developed piercing height. On reaching this height, the plasma arch strikes and the menu begins to get pierced While spear like takes place, a new lot of molten metal (depending for the thickness of typically the plate being pierced) jumps out involving the plate plus forms a pool area. The torch must be protected from this molten metal, and so the torch carries on to move upward to a programmed "molten pool jump" height.
iii) The torch now goes downwards to the particular programmed cutting height. The THC product now provides a transmission to the COMPUTER NUMERICAL CONTROL to start activity
iv) The torch now continues to move exact same reducing height. Arc volts is constantly provided back to the particular control unit, which usually keeps a constant arc voltage through an appropriate PID handle loop.
9-8215 electrode
These discourse amply demonstrates typically the role of the good THC for the very good cut with plasma.
