flygilmore

I am going to run a single battery in my next plane but want to run two switches (RX) to have a backup if one switch should fail. Anyway, just wanted to check and make sure what I am thinking is correct. I have allready soldered my extra connector to the batt so I now have two leads coming from the pack. Can I plug one lead into the batt port of my rx from switch #1 and the other into an unused port from switch #2? Just wanted to make sure that this was the correct way to do this.

Thanks.

3D_Junkie

That will work just fine. I usually solder the two switches into a single connector, the end effect is the same.

Edgar Perez

My Feedback: (13)

A Y lead will also work

3D_Junkie

I try to minimize the number of connectors in the circuit. To me, each connector is a choke point for current flow. Here is a diagram of how I setup my 50cc birds.

chrisF test pilot

Why not just use a good failsafe switch like the Fromeco that will fail closed. Adding more connectors just adds more failure points, and how often do you see a switch fail in flight anyway. They almost always give you some warning. I just replaced one in a 40 size pattern plane, replaced the rx pack with an A123 and realized I was getting .4v drop across the switch. If I hadnt payed any attention to it that would have been a disaster.

dragoonpvw

My Feedback: (7)

" Adding more connectors just adds more failure points" Of course it does. That is the whole point . Adding that one extra "failure point" as you call it makes the set up safer. That is how redundancy works. Every time you make any single point of failure redundant then the chance of total failure declines. By the way, yes I have seen a swiitch fail in flight, plus I have seen a few batteries fail and various connectors.
this is a good simple way to start working on system redundancy.

MR G

N7160F,

Nice diagram, Do you charge your A123's through the charge jacks on the switches or do you have to remove your batteries for charging?

Thanks

MR G

3D_Junkie

I do charge the batteries through the charge jacks on the switches. On the receiver side, one of the switches is used for charging and the other is used to bind the receiver. If you setup your system to bind like I have, be sure that you lable the charge jacks on the switches. Wouldn't want to introduce a dead short when trying to bind the system. Also, in some DSC style switches, the signal wire does not pass through the switch. I know that the EMS JR switches do hence why I have them specifically labled.

And to address the redundancy questions. I didn't make this setup for redundancy; I made it solely for current flow. The increase in redundancy is an added benefit.

And no, the point of redundancy is not to "increase the number of failure points", it is to make the system hardened against single point failures such that no single failure can cause a catastrophic loss.

It is a known fact that a single standard servo connector can only handle 4-5 amps, above that and the voltage drops to maintain lower current flows. With 5 high torque digital servos, this amperage is guaranteed to be exceeded during the more extreme 3D maneuvers.

MR G

N7160F,

Your ignition battery is wired without the balancing lead. Do you charge that way?

FWIW, I read somewhere that balance charging A123 batteries is not necessary because they will self balance if all of the cells are in good shape.

MR G