Node TigWelder

PoE powered Node on AC voor de Tig Welder.

Normal operation

Turn ON

1. Check both pressure dials. They should both show pressure.
   1. If not - they may be empty and someone before you may have not bothered to replace the bottle. Baad. Check by turning the welder on and trying to weld.
   2. If that works - then you may have to fix the leak or report this to the mailing list - so it can be fixed.
2. Open main valve on top of the gas bottle.
3. Swipe tag
4. Turn on with the switch on the front

Turn OFF

1. Turn off with the switch on the front
2. Close the main Values on top of the gas bottle.
   1. Node beeps to remind you to do so.
   2. Node will stop beeping
3. Check the pressure
   1. If it is below XXX - arrange for a replacement bottle and report this to the mailing list.

Do not unplug the welder; leave the power cable in the wall socket. We use this to track gas leaking and usage.

Trouble Shooting

No Gas ?!

1. Are BOTH valves open ?
2. Do the meters show pressure
   1. If not - you've ran out of gas. Arrange for a replacement -and- report to the mailing list. Be wary of the 125L limit.

Swipe ok - but does not want to turn on

1. Do you see waiting for card on the display ? If so - it has not read your card (yet).
2. Did you hear a beeb when you swiped ? If so - your card is picked up ok.
3. Did you hear 3 or more beeps when you swiped ? If so - your card is not getting permission from the system
4. Does your personal page in mijn.makerspaceleiden.nl show that you have permission ?
5. Is the internet in the space up and running ?

The Machine does not want to accept my badge

1. Do you hear a beeb when swiping ? If so - it has read your card.
2. Did it work on the door ?
3. Does it work on any other machine ?

Resetting the Node

Unplug the main power cable of the welder from the wall scocket, wait 10 seconds and then re-seat it.

Wait about 10 seconds until you try again.

Trouble shooting

The first QR code will bring you to this page. The second QR code will show you the logs in a browser. You can also telnet to the IP address shown in the 'MORE' display to see the log in real time.

See this page for more details.

Electronics

TIG AC Node, schematics

De node is AC powered; en zit 'voor' alle electra van het TIG apparaat.

Het SSR relay onderbreekt de spanning naar de on/off schakelaar. De stuurstroom van dit SSR schakelt ook shutoff valve.

OPTO1 wordt gebruikt om spanning na de on/off switch the detecteren.

OPTO2 wordt gebruikt om de spanning op de solenoid te detecteren die in het tig apparaat de gas toevoer naar de toorts regelt.

De tweede output wordt gebruikt om de solenoide binnen in het tig apparaat open te zetten.

De node is gebaseerd op de Black 2025 boards. Machine specific wiring:

• SSR relay voor power; stuurstroom 12v - ook gebruikt voor de shutoff valve
• Relay voor 220v solenoid in de machine.
• Opto voor spanning detectie main on/off schakelaar
• Opto voor detectie solenoid spanning (220v)
• XGZP6847D i2c pressure sensor (0-1 MPa / 0-10 Bar)

Solenoid Wiring

12V solenoid with on-current reducer

The 12V solenoid uses about 0.5 Amp/6Watt when fully engaged. This makes it relatively hot; and also is a stretch for the AC/DC power unit used. So after a high on-peak current- we reduce this to about 1/3 once engaged with a resistor. See https://www.electronicdesign.com/technologies/analog/article/21798400/whats-all-this-solenoid-driver-stuff-anyhow for details.

Board jumpers and settings

Board - serie nummer 4

1. Rework 1 - verwijderen ESD diodes antenne
2. Rework 2 - omdraaien transistors programmering

Note: een van de program-transistors is vervangen door iets willekeurigs

Jumpers:

1. Vint, 12 volt
2. Vpoe/SS - all off

Green Connector

PIN	Description	Use
1	CUR2	NC
2	CUR2	NC
3	OPTO 4	NC
4	OPTO 3	NC
5	OPTO 2	N from TIG welder, post on/off switch
6	OPTO 2	Torch/solenoid sense
7	OPTO 1	N from TIG welder, post on/off switch
8	OPTO 1	Voltage sense post on/off switch
9	L input	L, connected, from plug
10	N input	N, connected, from plug
11	Relay 1 NO	L power, to TIG
12	Relay 1 Common	L power, from plug
13	Relay 2 NO	L power, to solenoid
14	Relay 2 NC	NC
15	Relay 2 common	L power, from L voltage sense post on/off

Montageplaat ZP150.150.60J

ZP150 dimensions

For a 150x150 TME enclosure; main dimensions

• 140x140
• Holes at 120; 10mm from left/right
• Holes at 125; 7.5mm from top/bottom

Checklist node

Doel checken is

1. Machine mag niet anders aan gaan dan met de schakelaar voorop
2. Powercycle van de node moet geen rare situaties opleveren
3. Spanningsonderbreking moet machine in veilige stand brengen.
4. Timeout na X minuten moet de machine ook in veilige stand brengen.
5. Machine mag nooit uit (of aan) gaan zonder gebruikers actie. Dus node/netwerk/etc verlies of een timeout mag niet leiden tot uitgaan of aangaan van de motor.

Stappen:

1. Powercycle de node. Komt die terug op het netwerk ?
2. Na powercycle; kan je de unit niet aan zetten ?
3. Swipe, check dat de machine werkt. Zet hem uit. Onderbreek de stroom > 1 seconde en controleer dat de machine weer in de veilige stand staat.

Source code

https://github.com/MakerSpaceLeiden/AccessSystem/lib-arduino/ACNode/examples/TigWelderNode

Bypassing the node

With the explicit permission from a trustee - a node can be bypassed. For example when it is broken. There are two dip switches on the board.

Obviously - doing so without the express permission is a sure way to loose your membership.

Bill of material

AC/DC 12V	~2€
Solenoid 12V	~9€
Current coil	~1.50€
Connector	~1.50€
OLED display	~3.50€
Buttons x3	~0.30€
Solid state relay, 40A	~7.82€
12v coil relay; switch 240ACV/3A, schrack	~3.50€
150x150 enclosure with transparant lid	~9.00€

History

Build late 2024