If all you are trying to do is deploy the legs there are some easy ways to do
it without pneumatics and solenoids.
Day job project a bunch of years ago was to deploy wings on a 'glider' um
shall we say it was deployed at high speed and didn't need a parachute. Simple
cheap and light.
On Jan 25, 2017, 2:04 PM, at 2:04 PM, R Dierking <applerocketry@xxxxxxxxxxx>
wrote:
Wow, I don’t know about others, but I learned a bunch on this thread!!!
I’m considering connections, batteries and power arrangements, and now
learning about these solenoids I picked up. BTW: I searched for info
on the solenoids and even called the manufacturer but it’s a
discontinued product with no documentation. So, I appreciate the info.
I want to use the solenoids to control pneumatics for retractable legs.
Basically, ground launch the rocket with the legs extended and bring
them in as the rocket accelerates. The fins would be on the ends of
the legs.
Anyway, that’s the plan. And, I thought I was busy when I was working.
??
Richard Dierking
From: Vern Knowles<mailto:knowles.vern@xxxxxxxxx>
Sent: Wednesday, January 25, 2017 12:14 PM
To: roc-chat@xxxxxxxxxxxxx<mailto:roc-chat@xxxxxxxxxxxxx>
Subject: [roc-chat] Re: Resistance for Electric Matches
I would caution against removing the diode. An SSR has no magnetic
field but the solenoid does! The diode is there to prevent the voltage
spike generated by the solenoid from damaging the SSR.
Vern
From: roc-chat-bounce@xxxxxxxxxxxxx
[mailto:roc-chat-bounce@xxxxxxxxxxxxx] On Behalf Of David Erbas-White
Sent: Wednesday, January 25, 2017 11:13 AM
To: roc-chat@xxxxxxxxxxxxx
Subject: [roc-chat] Re: Resistance for Electric Matches
On 1/25/2017 10:07 AM, Mike Kramer wrote:
Mike,
Not needed for SSR, it's simply for those that operate magnetically.
The collapsing magnetic field can produce a very large voltage spike in
the opposing direction -- not a lot of power behind it, which is why
the diode can handle it (while keeping the negative voltage minimal),
but the magnitude of the voltage can damage control circuitry. By
definition, the SSR has no magnetic field that you have to worry
about...
David Erbas-White
P.S. It might be that some SSRs would require a diode wired differently
in order to ensure you don't accidentally reverse the polarity, but one
would think that is built in to most SSRs these days.
Do you need the diode for SSR? Or just mechanical coils and relays?
Mike
