long time lurker here sorry.
Just read this, and thought, wouldn't the best safing "key" be one that
that mechanically prevents the actuator from operating?
Bonus points if the actuator has attempted to operate, and locks the saving
key
in place so that it can't be removed.
I'm thinking some type of key with a big red "Remove before Flight" tag,
that is accessed via a small hatch or a slot.
As long as all is good, the tag and attached key can be removed fairly
easily,
but if the actuator has attempted to move, the key and tag become locked in
place.
just a thought...
On Mon, Nov 9, 2015 at 10:55 AM, Robert Watzlavick <rocket@xxxxxxxxxxxxxx>
wrote:
I suppose that would work but I was considering something a bit more
durable such as a shorting plug. Plus, I have several different power
supplies (see my reply to Monroe's post).
-Bob
On 11/08/2015 10:16 AM, William Claybaugh wrote:
I favor a twisted pair sticking out the side of the vehicle with both
sides taped. For arming, uncover, twist and re-tape and stuff inside.
Bill
On Sunday, November 8, 2015, Robert Watzlavick < <rocket@xxxxxxxxxxxxxx>
rocket@xxxxxxxxxxxxxx> wrote:
I'm working on the power electronics for my liquid rocket and I'm trying
to decide the best way to handle safing of the vehicle during pad
activities. The absolutely safest way is to just turn off all power to the
vehicle during propellant loading and troubleshooting but I'd like to keep
the avionics (IMU, pressure sensors, etc.) powered and warmed up for best
stability. The valves are controlled via RS-232 servos (AX-12) so there's
little chance they would get an uncommanded actuation. I thought about
having a SAFE/ARM switch that controls power to the igniter CDI, igniter
valves, recovery system, and maybe also the servo valves (main, vent,
helium). However, I'd want to make sure that switch is appropriately
vibration and shock rated so I don't get intermittent power interruptions
when the vehicle is operating. What has been done in the past? Here's a
good question - if you were helping me out on the pad, what level of safing
would you want to see for your personal safety?
Thanks,
-Bob
