Automatic Ignition

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• Ignitor - 24V power supply + nichrome wire
• Uxcell FeCrAl 1mm 18 Gauge AWG 0.45 Ohms/ft Heater Wire 7.5Meters
• FeCrAl(22% Cr,58% Al,Fe Balance);
• Brand: DMiotech
• Average Wire Diameter: 1mm; Wire Gauge: 18 AWG
• Wire Length: 7.5M / 25Ft; Melting Temperature: 1500C (2730F)
• Max. Operating Temperature: 1250C (2282F); Resistance/Foot: 0.45 Ohms/ft (1.477 Ohms/m)
• Power dissipation - Use 120V for faster activation
• V=IR
• I=V/R
• For 20A, Resistance should be
• 20A=120V/6 ohms
• Better to use 12V
• 20A=12V/0.6 ohms
• -> Need 1.3 feet of nichrome

Automatic Ignition

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• Current required for a given temperature of wire:

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• Design consideration: run as much current as possible for as short a time as possible to get quick heating and ignition within ½ second after gas is turned on
• Logic:
• Turn on the ignitor at 20A, 2 kW
• Wait ½ second
• Turn on the acetylene for immediate lighting
• Wait ½ second
• Turn off ignitor
• Auto ignition temperature - 581F

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Gas System + Ignition

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• RAMPS Controller for both motion and gas
• 12V gas solenoid 1 - ½ A
• 12v solenoid 2 - 1 A
• 12v solenoid 3

Cutting Oxygen

Heating Oxygen

Heating Acetylene

Heating

Shutoff

Oxygen Lance

Nichrome Ignitor - 20A

120 AC

12 VDC

12 VDC

12 VDC

12 DC

20A

Hose Y Splitter

Gas System - Oxygen Hose is Split into 2

Hookup