Laser Shutter Controller LSC01

Fig. 1: Front and rear panels


The LSC01 is supplied with two cables: a mains cable and one to connect to the shutter head terminated in
the D type plugs. The controller is powered from an 85V – 260V ac supply connected to the rear panel IEC
receptacle. The shutter is connected, using the cable supplied, to the rear panel 9-pin “D” socket labelled
SHUTTER. If required, the shutter can be controlled and monitored remotely via the other 9-pin “D” plug
labelled PC.


The front panel push button switches the controller mains power on or off. It is illuminated when powered on.
Before switching on, check that the toggle switch is in the closed position or if being controlled from a PC,
that a ‘close’ signal is being sent. This will ensure that the shutter does not open unexpectedly on power-up.
The toggle switch opens or closes the shutter. The left position will open the shutter and the right position will
close the shutter. Note that if the controller is switched off at the mains, the shutter will default to the closed
The red OPEN indicator will light when the shutter is open. The green CLOSED indicator will light when the
shutter is closed. (Note: Other ULO Optics shutters ‘ESU’ types have a manually operated lock that allows
the shutter to be locked in the closed position only. The yellow LOCKED indicator will light to indicate this.
The CO2MPACT shutter C-SU does not have a lock, so the yellow LED is inactive).
The status of the shutter can also be monitored via the rear panel 9-pin PC connector. Opto-isolators are
used to give a grounded signal to indicate open, closed or locked and a high impedance for the inverse. The
shutter can be opened by applying 5V to the shutter enable pin 3 relative to GND. Note that to operate the
shutter from a computer, set the toggle switch to the CLOSED position.
Fig 1: D connector pins on rear of LSC01
Beam delivery

Circuit Operation
The shutter solenoid is connected between connector SHUTTER pin 1 (+12V) and pin 3 (TR1 drain). When
switch SW is switched to CLOSE, the gate of TR1 is pulled low by R2 and so TR1 is switched off. Therefore
no power is applied to the solenoid and the shutter assumes the default-closed position.
When SW is switched to OPEN, TR1 gate is pulled up to +12V and TR1 is turned on. This provides a current
path from +12V through the solenoid to 0v, and so the solenoid energises and the shutter opens.
The shutter status switches are connected between +12V and connector SHUTTER pins 6, 7 and 8. When
the OPEN status switch closes, it connects R1 to +12V so that LED1 lights and current flows through the
emitter of the opto-isolator, IC1 causing the output transistor to turn on. Operation of the CLOSED state is
similar. Note that the ‘Locked’ function and LED3 are not relevant to the C-SU.
If SW is in the CLOSE position, then the shutter can be controlled via connector PC. If PC pin 3 has +5V
applied with respect to pin 9, then current passes through fourth opto-isolator IC1 emitter and IC1 transistor
is turned on. This will pull up the gate of TR1 and so turn it on. The solenoid will be energised and the shutter
will open.laser-shutter-controller


Fig 2: Internal circuit of LSC01 controller
Note that if you wish to control the shutter using a higher voltage than 5V, then you need to add an
external resistor in series with R4 (390R). The value should be, R = 80Vcontrol – 390 and its power
rating > R/6400 W.
Also note there are no pull-up resistors to the status pins. They have been left as open collector, so that
the user can select the correct value according to their supply and desired signal.