Both
of the sync modes require that an external signal be applied
to the Sync Input. In the Sync-Phase mode, the LS310 locks on
to the external input frequency precisely, and then flashes
at various phase offsets within the 360 period.
The default phase resolution is 10 degrees. For each period
of 360 degrees this means there will be 36 possible steps. The
strobe will flash for a duration of 10 degrees or 1/36 of each
period. Where in the period the strobe flashes is controlled
by this phase offset.
The sequence of scope photos on the right shows the phase offset
stepped through 10, 20, 30, 40, and 50 degree offsets. The Yellow
trace is the sync input signal and the Green trace is the trigger
output. The strobe flashes during the positive pulse.
For electroacoustic work the Sync-Phase mode will produce a
visual display of the moving diaphragm frozen at a particular
position. As the phase offset is changed, the diaphragm will
be frozen at different positions of its travel through the entire
period. As the frequency is changed the phase offset position
is always maintained.
The phase resolution is in effect during all operating modes.
If the resolution is set to 10 degrees, then the flash duty
cycle is 10/360 or 1/36 or 2.78%. Thus the continuous light
power of the strobe is reduced by a factor of 36. The user can
change the phase resolution from 1 degree to 45 degrees, thus
providing highly different resolutions, number of steps, flash
duty cycle, and equivalent light intensity.
There is an inherent trade-off between the phase resolution
and flash intensity. While it is desirable to have the smallest
possible resolution to provide a clear frozen visual image,
it also reduces the effective strobe light power proportionally.
For example, a phase resolution of 1 degree produces extremely
narrow flashes but also reduces the flash power to 1/360 or
0.278% duty cycle. Using a resolution of 10 degrees generally
provides the best trade-off between the competing requirements. |
| |
| Windows
Application Software |
The
LS310 has additional parameters which can be controlled through
the provided Windows application. The LS310 is fully programmable
via RS-232 commands. The user can control the strobe remotely
through custom RS-232 software or the Win32 DLL interface.
|
 |
|
 |
|
