| Experiments
General:
Laboratory
Equipment
-
Suggestions
about what equipment you might consider buying and a list of my
own equipment.
Test
Coils Description -
These
are the coils which are used for the majority of the basic experimental
work.
Test
Coils Data -
This
gives the parameters of the test coils.
Test
Projectiles -
A
range of projectile types have been produced for general experimental
work. This details the projectile parameters.
Experimental
Energy Sources -
No,
not new types of energy sources, just the specific details of
the systems I'm using.
Instrumentation:
Experimental
Rig -
The
experimental rig is where most of the coilgun testing is conducted.
At the moment it consists of a base platform with coil mounting
flanges, a raised module platform.
Optical
Speed Trap -
This
system allows the velocity of the projectile to be determined
to a high degree of accuracy.
Current
Sensor Module -
This
is a simple module which can be inserted in the current path to
make measurements.
Experimental
Measurements -
A
basic introduction to measuring the various different parameters
during a firing sequence.
Triggering
and Switching Systems:
Open
Loop Pulse Trigger Module -
Based
on the 555 timer chip, this module can produce any pulse width
between 100us and 100ms.
Optical
Trigger Module -
This
details a basic optical triggering device which is suitable for
velocities up to 50m/s.
Power
MOSFET Module -
A
self contained module with screw terminals is described. This
is the switching device used for all of the low power experimental
work.
MOSFET
Switching Issues -
Looks
into the potential problems of switching MOSFET devices.
Switching
Transient Suppression -
This
experiment takes a brief look at the overshoot and ringing which
occur when the current is switched off in a coil circuit.
Induced
Voltage Trigger -
An
induced voltage trigger for use with single stage coilguns is
developed.
Multi-stage
Induced Voltage Trigger -
Several
trigger stages are combined to provide a cascading trigger system.
Coilgun
Performance:
Open
Loop Pulse Triggering -
This
triggering method is used to investigate how critical the current
timing needs to be.
Optical
Triggering -
Triggering
with an optical gate is a highly reliable method. These experiments
look at how this triggering method compares to the best open loop
results.
Induced
Voltage Triggering -
Sensing
of the dynamic flux linkage can be used to determine the projectile's
position in the coil. This method is investigated for both battery
and capacitor voltage sources.
Diode
Commutation Modification -
The
rate of current decay in a coil can have a significant effect
on the resulting muzzle speed. These experiments look at a 'constant
voltage' decay in which several commutating diodes are connected
in series.
Launch
Position Effect -
The
launch position is shown to have a large effect on the resulting
velocity and efficiency.
Thyristor
Fired Coilgun -
A
simple thyristor fired coilgun is examined.
Enhanced
Flux Linkage -
A
powdered-iron shell flux path is used to improve the efficiency
of a single stage coilgun.
Last
Modified: 10 Jan 2005 |
