Laser Interface Last update: 2019-08-13
Power Supply Instructions
Manufacturers wesite (we have the X3
Laser Interface Functional.
The signal LaserEnable is given by the SFB when all conditions are
such that the CO2 tube can be operated safely. In particular when
the waterflow is to low the LaserEnable signal will be inactive
The signal LaserON origines on the SMB, SFB "listens along" to
determine the laser-On time for accounting, but the SFB can also
switch the laser on for test-shooting. For this we have the "wired
or" function with the open collector drivers.
The laser power % is controlled by a PWM signal from the SMB to
have the laser intensity modulated by the job. Alternatively the
power % can be adjusted by hand on the console. For that the relay
K1 is activated and a locally generated PWM signal is sent to the
HVPSU. The indicator on the GUI always shows the actual PWM% which
goes to the HVPSU.
The actual voltage on the CO2 tube is measured with a voltage
divider of 700 MegOhm to 100 kOhm, giving a range of 35 kV with
the ADC range of 5 Volt.
The current through the CO2 tube is indicated by the mA meter on
the console, protected with 2 diodes, and measured on the SFB with
the shunt resistor. of 140 Ohm giving a range of 35 mA. The
shunt resistor and the diodes are located very close to the HVPSU
so there is little risk of getting a loose wire with heavy
sparking in the middle of the elecronics compartment.
Also see the signal descriptions for the Safety Board.
Signal connections to the HVPSU.
To allow us to measure the actual voltage on the tube we need a
3-way coupler suitable for this high voltage.
It was made from a piece of acrylic material 25 x 25 x 60 mm I
happened to have in stock.
High Voltage Connector.
From the top 3 wires can be inserted and fixed with nylon screws.
High Voltage Connector before assembling.
About 10 mm from the bottom the wires are electrically connected
together by a metal ring.
The opening through which the ring is inserted will be closed by
the black cylinder (POM) wetted with 2-component glue.
As POM is hard to glue I made several grooves in it to increase
the surface area and make it unlikely to fall out or to allow
sparks to expell.
The wires will be insrted after slightly wetting with white
vaseline (pure petroleum yelly)
The drawing of the High Voltage Connector.