Matrix E-blocks Notice D'utilisation page 8

4. p
hysICal propertIes
E-blocks can be mounted onto a metal back-
plane to form a completely rugged system.
To facilitate this each E-block is fitted with 4
Fig 16 - Physical relationship of backplane to E-blocks
off 3 mm holes spaced at multiples of 20mm.
M3 bolts can be used to mount the E-blocks
onto a backplane which has 4mm holes on a
regular 20mm grid.
The spatial relationship between the mount-
ing holes on the backplane, the holes on the
E-blocks and the spacing of each D-type plug
and socket on the E-blocks are such that each
E-block will fit into another, and yet still be
mountable on the backplane.
Mounting options for backplanes
There are several options for mounting
E-blocks on a backplane depending on your
circumstances:
Temporary mounting with pillars
•
Custom moulded circuit board pillars are
available which allow you to loosely mount
boards to the backplane. This is ideal if you
are working through a course and frequently
reconfiguring the E-blocks system to give
yourself experience of different systems. Note
that these pillars are very tight initially but
soon loosen up. This is shown in profile in
Fig 17.
Fig 17 - Board with mounting pillars
8
If you are reconfiguring your E-blocks system
less frequently then we suggest that you use
M3 bolts on all your E-blocks and that you
use a metal backplane to mount them on. The
E-blocks can be mounted on the backplane
with M3 self locking nuts - these will keep
the bolts secured onto the circuit board and
will act as spacers to keep the board clear
of the backplane. (See Figure 18) When you
want to move the system around then one
or two additional nuts behind the backplane
will ensure your E-blocks stay in place. For
best results with this mounting technique you
should attach the bolts and self locking nuts
and then slacken off the nuts by a quarter
turn - this allows the bolts a little movement
in the PCB mounting holes and makes them
easier to take off the backplane. If you are
Fig 18 - Board with 12mm bolts
concerned about preserving the painted finish
of your backplane then you can substitute the
steel bolts with nylon ones. However we have
found the powder coating of the backplanes is
sufficiently strong not to warrant this.
Using E-blocks on the bench
You do not need a backplane to use E-blocks
- you can simply connect them together on
the bench. In each E-blocks package you will
find a four small rubber feet to facilitate this.
These will provide a degree of protection for
your E-blocks boards and will help prevent
shorts from tinned copper wire and other
Fig 19 - E-blocks on the bench