[roc-chat] Re: ROC Launch Control System
- From: "Jim - TFJ" <jim@xxxxxxxxxxxxxxx>
- To: <roc-chat@xxxxxxxxxxxxx>
- Date: Tue, 9 Oct 2012 08:20:51 -0700
If you're using a processor at each group of pads, you could program the
buzzer/siren make a different sound if continuity is lost.
Jim G.
_____
From: roc-chat-bounce@xxxxxxxxxxxxx [mailto:roc-chat-bounce@xxxxxxxxxxxxx]
On Behalf Of Richard Dierking
Sent: Monday, October 08, 2012 9:26 AM
To: roc-chat@xxxxxxxxxxxxx
Subject: [roc-chat] Re: ROC Launch Control System
The most important safety feature is having the shunt/power switch
(mechanical switch) at the pad with a visual and audible warning that the
pad is armed. This puts the responsibility for safety back in the hands of
the person loading their rocket.
I think having a continuity check at the pad is a good thing, but don't
think the continuity check at the LCO for a high-power rocket pad is that
important. If the rocket doesn't go when the button is pushed and there's
continuity at the pad, it's a recycle and the igniter must be checked. If
the rocket doesn't go and there isn't continuity, the igniter must be
checked. So, really what's the value of having a continuity check if the
rocket doesn't launch?
Regarding the battery, it shouldn't take a large battery for the individual
launch pad controllers. We launch 6 rockets all day using a 12 volt gel
cell 7 Ah battery.
Regarding the front row and model rocket pads, these could still use cables.
However, I think that some kind of digital system using Cat 5 cable would be
better. It's not expensive cable to replace if necessary, and a lot easier
to deploy and hook up.
If ROC budgeted to save $2000 per year (approx $175 per launch), this would
probably be enough money to develop a wireless system and go wireless for
the high-power pads in approximately 3 years.
Richard
On Mon, Oct 8, 2012 at 7:29 AM, Richard <rocket_hall@xxxxxxxxxxxxx> wrote:
David is this possibly a XBEE module? The XBEE modules could accomplish
exactly what Richard's dream system would need. I have some experience with
these too. Richard Dierking I can put together a couple of concepts both
"dream system" and "partial dream system" The biggest problem I see would be
batteries(one per pad). I won't be at ROCtober but will be at ROCstock.
Richard C. Hall
TRA 11515
-----Original Message-----
From: David Erbas-White
Sent: Oct 7, 2012 7:14 PM
To: roc-chat@xxxxxxxxxxxxx
Subject: [roc-chat] Re: ROC Launch Control System
On 10/7/2012 6:03 PM, Richard Dierking wrote:
In my 'real life' job I'm working with some wireless systems (actually,
using a wireless module with our own proprietary control circuitry -- but as
the module is FCC approved, don't need to worry about that end of it). I
have tested this system on the lakebed to over a mile, reliably. If we were
to come up with some definitions of exactly such a 'wireless dream system'
were to do, I could perhaps cobble something up that would be extensible.
Effectively, the system I'm working with is a single-master, multiple-slave
system, which would be ideal for what we're doing. To avoid interference
from other sources, we would have to use secure encoding, along with timing,
to ensure safety (i.e., a secure code to arm the system, system disarms if
it either times out or loses signal from the master, etc.).
If we design a modular system (i.e., a relay box with batteries for doing
the actual firing, and a 'receiver section' that handles the wireless and
intelligence, we should be good to go. Current systems (as I envision them
using these components) would require a PC to act as the launch controller.
If we really wanted to, we could simply build a wireless box that 'looks'
like the current launch controller, but sends the proper signals via the
wireless master -- but I'm just kind of thinking out loud...
What might be the more difficult aspect (possibly) would be the continuity
detection (wirelessly), as we would need to have the circuitry in the
range-head box to 'tell' the wireless unit if continuity was present, etc.
And this circuitry would need to work in conjunction with the current system
of the push-button/buzzer for the pad area itself. We'd also need to ensure
that we can handle the wider-range of igniter firing levels (like the new
Quest igniters) with such a system..
Love to hear what other folks might think...
David Erbas-White
Wireless System:
These types of systems (particularly multi pad systems) are just being
developed and there's not a lot of experience using them. If we had to
obtain a new system today, I would suggest a wireless system because of the
savings on the weight and cable cost. But we don't need a new system
currently, so let's see what's developed over the next couple of years and
listen to their experiences. In the meantime, we can save for a system so
when ROC's ready, we'll have the money for a safe and reliable system.
For me, my 'dream system' would look something like this: A small control
box would be located at each launch pad that would be the receiver for a
computer based wireless system. The LCO would launch rockets using a
computer and daylight monitor connected to a powerful (over 2,500' range)
wireless transmitter. The pad control box would have a shunt and power
switch controlled by the person loading the rocket and be located on a
ground stake that would also have the pad number sign. There would be both
audible and visual arm signal on the box and it would also have a connection
for a larger battery if necessary (i.e. more firing amps). So, no central
control boxes, just place the launch control box with the pad number sign
were you want a pad, attach the launch leads with clips, and away you go.
This would allow for any kind of spacing on rows.
Richard Dierking
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