Egg timer Quantum Power

[davdue]

Just built my first Quantum kit. It will be replacing another altimeter in my L2 rocket I certified with. My question is how many of you do dual batteries or single batteries with this altimeter when it is the only altimeter? The previous one was an Adept 22 that was destroyed in a failed L3 attempt 3 years ago.

 

[roytyson]

I set mine up for single power, fed off wifi switch.

 

[davdue]

So you have 2 WiFi to connect to? The Quantum has WiFi built in.

 

[roytyson]

Yea, I know. kind of redundant. The only advantage is I don't have to worry about power drain after assembling the rocket. I couldn't find much info on battery drain once plugged in and before arm. I know with a 1000mah I could wait nearly all day before taking it out.

 

[davdue]

I put WiFi switches in my L3 rebuild. I was tired of trying to line up holes in the airframe with the switch inside the avbay.

 

[cerving]

I fly almost all of them with one battery. If you're doing an airstart you should either use a second battery or put a 1 or 2 ohm 1/2 watt resistor in series with your motor igniter to limit the current in case of a dead short, which can be caused by motor plasma.

The Quantum does not NEED a separate switch, it has one built in. For most sport flights you don't need anything else. However, for a NAR L3 cert flight you MUST add a physical disconnect switch, and for a TRA L3 cert you might have to put one in... TRA leaves it up to your TAPs.

 

[Eric]

Like Cris, mine are wired up for single battery use. I think he stated the quantum draws 80mAh. I have a 600mAh that fit in the printed 9 volt box. Should have no problems sitting on the pad for hours.

I now use Quantums as an add on back up altimeter, after a single alt failed with a plugged motor flight. I just attach it and it battery to the sled. No switch. Plugged in at the prep table. Simple add on redundancy.

 

[davdue]

Thanks for your answers. I was leaning towards single battery. I have always had single batteries on other altimeters so figure why not here as well. Also I have a relatively small av-bay. It is in a PML 4" to 3" transition.

 

[KenRico]

2S Lipo 360mah is a good start ..if room use a 2S Lipo 500-600mah is only a buck or two more :

https://hobbyking.com/en_us/rhino-610mah-2s-7-4v-20c-lipoly-pack.html

Its flat so easy to secure to sled .

Kenny

 

[dshmel]

Has anyone wired two separate altimeters to a single WiFi switch powered by a LiPo? I know this would not be allowed in a cert attempt, just wondering if it has been done.

 

[Steve Shannon]

Has anyone wired two separate altimeters to a single WiFi switch powered by a LiPo? I know this would not be allowed in a cert attempt, just wondering if it has been done.

Being wired to a WiFi switch in a L1 or L2 cert attempt would be permitted by Tripoli. A single WiFi switch wired to two altimeters would fail the redundant electronics requirement for L3 though.
Other than cost, why would you?

 

[dshmel]

Being wired to a WiFi switch in a L1 or L2 cert attempt would be permitted by Tripoli. A single WiFi switch wired to two altimeters would fail the redundant electronics requirement for L3 though.
Other than cost, why would you?

To save space. I might imagine an application where 2 batteries, 2 WiFi switches and two flight computers might not fit. According to Eggtimer, the WiFi switch can handle 13A. Given that the altimeters would likely not fire their e-matches at the same time, I think a LiPo could handle the current needed.

 

[ttabbal]

It creates a single failure point, so now the electronics are not redundant. It can handle it, and it will likely be fine. Unless something in the switch path goes wrong. If space is that tight, perhaps a Quantum with the main backup feature enabled would be a better option.

 

[cerving]

If you're going to put two altimeters in a build, you need a separate battery and switch for each altimeter. Otherwise, as has been previously mentioned, you have a single point of failure. I've had people ask me about double-pole switches, same thing... if the switch bounces, you lose both altimeters. That's the nice thing about the Quantum... it takes a switch out of the equation, so there's one less thing to fail. It also saves room... it makes putting two altimeters a lot easier in a skinnier build like a 54mm, or even a 38mm if you lengthen the AV bay slightly (to about 7" or 8").

 

[dshmel]

... I've had people ask me about double-pole switches, same thing... if the switch bounces, you lose both altimeters. ...

Are you referring to the commonly used Schurter rotary switch?

 

[mccordmw]

I fly almost all of them with one battery. If you're doing an airstart you should either use a second battery or put a 1 or 2 ohm 1/2 watt resistor in series with your motor igniter to limit the current in case of a dead short, which can be caused by motor plasma.

The Quantum does not NEED a separate switch, it has one built in. For most sport flights you don't need anything else. However, for a NAR L3 cert flight you MUST add a physical disconnect switch, and for a TRA L3 cert you might have to put one in... TRA leaves it up to your TAPs.

Got my TRA L3 using two Quantum each in their own single battery. No additional wifi or physical switches were needed. Life Chris said, the individual TAP will decide if you need a physical switch.

 

[davdue]

My L3 was done with WiFi switches to remove the problem of access holes for switches. I already had switches mounted so I used them to turn the power on during the launch prep process and the WiFi switch to arm. In the future I plan to build new rockets using the Quantum.

 

[Wallace]

I have run a Quantum and an Eggfinder mini on a single 450mah lipo many times. Two altimeters means two batteries though.