concise manual - CandCNC

Product DescriptionHow Torch Height works with PlasmaThe important thing to remember is that the Arc Volts (we refer to it as Tip Volts) is a reflectionof arc gap and when the gap increases the arc volts increase. Conversely when the arc gapdecreases so does the arc volts.The operation of THC within MACH is important to understand. The logic and processingpower of the PC is used with MACH to replace most of the expensive external logic andelectronics required to have a fully functional Torch Height Control. The LCTHC (and DTHC)do not directly move the Torch up and down. The torch is mounted on a conventional Z axisunder control of MACH. Because of that the table can be used for any 3 axis operation THCbeing one of those operations. The Digital electronics in the LCTHC measures the Arc Gapvoltage thousands of times per second, averages it and compares it to a preset (Target)voltage. It then issues a simple logic UP or DOWN command to MACH. MACH reads theinputs 6000 times per second. It’s internal core THC logic looks to see if the THC Button is on.If it is and the torch is fired it waits until is gets a valid ARC OK (often called different names bydifferent plasma vendors) and then will read the UP or DOWN input. It is up to MACH then toactually move the motor at a rate that does not cause lost steps or drive faults. It is similar toan external jog command but different parameters are used.??Arc Gap = Arc volts=Tip Volts1volt (change) = approx .015”(change)>Arc volts = > Arc Gap. (greater the Arc Gap thegreater the Arc Volts)Z moves opposite Arc Volts based on Preset Volts.Torch Volts Above Preset LOWERS torch; Torch Voltsbelow Preset RAISES torch.? Control has “window” (Span Volts) where no UP orDOWN occurs. (prefect cut height) Anything inside theSpan (+ or -) from the Preset generates NO change.SPAN VOLTS is preset in the LCTHC to one arc volt (+ or- 1 V)Arc Gap-Gap Volts+Page 7