Tempest Nd:YAG Laser Operator’s Manual
32
External Q-switch triggering allows the user to fire the Q-switch
externally while the internal electronics control the flashlamp firing. The
user must supply a TTL pulse to the Q-switch trigger with the
appropriate delay following the internal flashlamp pulse. The Flashlamp
toggle switch should be up (INT) and the Q-switch toggle switch should
be down (EXT). The delay between the flashlamp and the Q-switch
TTL fire pulses is important in getting optimum laser performance.
The trigger selector switch on the control panel determines the operating
mode, 1 shot, continuous or variable. In 1 shot mode, the flashlamp is
fired once each time the Fire button on the control panel is pressed. In
Fixed mode, the flashlamp fires at the maximum repetition rate of the
laser. In Variable mode, the flashlamp fires at the repetition rate set by
the control knob, shown in the LED display. In Fixed and Variable
modes the flashlamp begins firing when the Fire button on the control
panel is pressed.
The Q-switch must be fired using a user supplied TTL pulse at the Q-
switch fire BNC. The flashlamp synch out pulse may be used to trigger
an external delay generator that creates the Q-switch fire TTL pulse.
External flashlamp triggering allows the user to fire the flashlamp
externally while the internal electronics control the Q-switch firing. The
user must supply a TTL pulse to the flashlamp trigger to start the laser
firing sequence. The internal electronics will fire the Q-switch after the
default delay. The Flashlamp toggle switch should be down (EXT) and
the Q-switch toggle switch should be up (INT). The delay between the
flashlamp and the Q-switch TTL fire pulses is important in getting
optimum laser performance.
External TTL direct triggering allows the user to externally control many
laser parameters. User supplied control signals are sent through the TTL
Direct DB 25 connector on the back of the power supply. The
impedance of the signal inputs is approximately 1 MΩ. The remote box
must be removed because it is plugged into the TTL port (see pg 19).
The flashlamp and Q-switch toggle switches should both be up, in the
INT position. The control electronics provide the necessary triggers to
fire the laser in the selected mode.
The pin assignments for the DB 25 connector are shown in Table 4-1.
Further explanation of the control signal inputs and feedback signals are
given in Tables 4-2 and 4-3, respectively.
External Q-switch
Triggering
External
Flashlamp
Triggering
External TTL
Direct Triggering
To Next Page
Loading...