Power Expander or not -that's the question
01-14-2009, 09:40 AM
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RE: Power Expander or not -that's the question
[/quote]
What did you do to Hammbone? He all but disappeared.
[/quote]
I've removed my subscription to this thread.
I'm done argueing with guys that ignore the facts and call people that have done testing that proves my points liars.
I'm done argueing with guys that think that the laws of physics don't apply to them.
If you want to use inline switches rated at 5 amps, standard plugs rated at 3 amps, substandard wiring, etc. and get voltage drops and limited current flow, go right ahead and do so.
The real shame is that some of you are recommending these poor set ups to others on the forums here, and I feel bad for the guys that are getting the bad advice. I guess there's nothing I can do about it though.
You won't see me argueing with ignorance any more on these forums. I've got better things to do.
If anyone does want some good advice on how to set up a plane properly, with good current flow and minimal voltage drops, feel free to e-mail or PM me. I'll be glad to help.
My goal from the beginning has only been to help.
Later, Jim
01-14-2009, 11:33 AM
#302
RE: Power Expander or not -that's the question
Welcome back !!!!!
Smart Fly designed that Super Switch for a giant plane Jim. Use two of them up to 40%. See my e-mail from Smart Fly that I posted a few pages back. Just because you don't like the switch doesn't mean it's bad. It's just your opinion.
Smart Fly designed that Super Switch for a giant plane Jim. Use two of them up to 40%. See my e-mail from Smart Fly that I posted a few pages back. Just because you don't like the switch doesn't mean it's bad. It's just your opinion.
01-14-2009, 11:37 AM
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RE: Power Expander or not -that's the question
It's not just my opinion, it's fact and it's the laws of physics.
Ask Smart Fly what kind of a voltage drop you will get if you try to push 10 to 20 amps or more through that switch that is only rated at 5 amps.
Ask Smart Fly how much of a voltage drop will you get if you try to push 10 to 20 amps or more through 1 or 2 standard connectors that come out of that switch and go into your rx.
And for those of you using JR HD switches........... I'm pretty sure that switch is rated at 5 amps also, but it just has one standard connector in and out. These standard connectors are only rated at 3 amps.
When you try to push 10 to 20 amps or more through these switches and standard plugs, you are going to get a substantial voltage drop. Voltage is what gives the servos their torque. Reduce the voltage and you reduce the torque. This is not my opinion, this IS FACT!
Jim
Ask Smart Fly what kind of a voltage drop you will get if you try to push 10 to 20 amps or more through that switch that is only rated at 5 amps.
Ask Smart Fly how much of a voltage drop will you get if you try to push 10 to 20 amps or more through 1 or 2 standard connectors that come out of that switch and go into your rx.
And for those of you using JR HD switches........... I'm pretty sure that switch is rated at 5 amps also, but it just has one standard connector in and out. These standard connectors are only rated at 3 amps.
When you try to push 10 to 20 amps or more through these switches and standard plugs, you are going to get a substantial voltage drop. Voltage is what gives the servos their torque. Reduce the voltage and you reduce the torque. This is not my opinion, this IS FACT!
Jim
01-14-2009, 12:04 PM
#304
RE: Power Expander or not -that's the question
That's 5 amps continuous. They'll never see 20 amps continuous on my planes. If you have that much current you have other problems.
PS: Did you see the e-mail reply from Smart Fly in this thread? It's not too far back.
PS: Did you see the e-mail reply from Smart Fly in this thread? It's not too far back.
01-14-2009, 12:32 PM
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RE: Power Expander or not -that's the question
I saw the reply.
Do like I suggested, ask Smart Fly what kind of a voltage drop you will get if you try and pass a momentary current flow of 10 to 20 amps through this switch and through 2 standard connectors.
It doesn't matter if the current flow is constant or momentary, you will just get either a constant or momentary voltage drop to go along with it.
This comes right off of Smart Fly's website:
"We have measured a digital servo, unloaded, drawing 0.6 Amp when kept in continuous motion. Imagine what the same servo is drawing under load and then multiply that by the six to eleven servos you have in the plane. While this may be momentary this is when you need the least voltage drop to the servo as voltage supplies the servos’ torque. Reduce the voltage the servo sees and you reduce the torque the servo can supply."
"We have measured a half volt drop over eighteen inches of 22 gauge wire and one connector at 5.0 amps."
Now if Smart Fly has measured a 1/2 volt drop when passing only 5 amps through 18" of 22g wire and a standard connector, how much more of a voltage drop do you think you are going to get when trying to pass 10 to 20 amps (even if it's momentary) through a 5 amp switch and 2 standard connectors?
Do you want your servos to get good voltage or not?
Why in the world would anyone use a $30 switch that's rated at 5 amps when they could use a $30 switch that's rated at 15 amps (Fromeco Badger switch)?
Why in the world would anyone give advice to a fellow modeler, and suggest that they use a $30 switch that's rated at 5 amps. when they could suggest that they use a $30 switch that's rated at 15 amps?
Jim
Do like I suggested, ask Smart Fly what kind of a voltage drop you will get if you try and pass a momentary current flow of 10 to 20 amps through this switch and through 2 standard connectors.
It doesn't matter if the current flow is constant or momentary, you will just get either a constant or momentary voltage drop to go along with it.
This comes right off of Smart Fly's website:
"We have measured a digital servo, unloaded, drawing 0.6 Amp when kept in continuous motion. Imagine what the same servo is drawing under load and then multiply that by the six to eleven servos you have in the plane. While this may be momentary this is when you need the least voltage drop to the servo as voltage supplies the servos’ torque. Reduce the voltage the servo sees and you reduce the torque the servo can supply."
"We have measured a half volt drop over eighteen inches of 22 gauge wire and one connector at 5.0 amps."
Now if Smart Fly has measured a 1/2 volt drop when passing only 5 amps through 18" of 22g wire and a standard connector, how much more of a voltage drop do you think you are going to get when trying to pass 10 to 20 amps (even if it's momentary) through a 5 amp switch and 2 standard connectors?
Do you want your servos to get good voltage or not?
Why in the world would anyone use a $30 switch that's rated at 5 amps when they could use a $30 switch that's rated at 15 amps (Fromeco Badger switch)?
Why in the world would anyone give advice to a fellow modeler, and suggest that they use a $30 switch that's rated at 5 amps. when they could suggest that they use a $30 switch that's rated at 15 amps?
Jim
01-14-2009, 12:44 PM
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RE: Power Expander or not -that's the question
there was a link a couple pages back to a test done actually fly, and while that test peaked at 17+ amps at 7.4v a lot of time it was pushing over 10 amps. if you are running lower voltage, ie:- 6v you will be trying to draw even more amps. Another interesting point that crossed my mind, what happens to the metallurgy of our wiring and connectors when pushed to the max often? A mate just bought a used 33% extra, and on giving it a once over we found it had binding issues on the elevators, they were nowhere near as responsive as they should have been, and had 8711a's fitted. We checked the wiring out and both leads had the wires go black and were barely conducting at all. the servo's were tail mounted with 36" leads, and a power board was used with 2 6v nimh packs, the airplane supposedly had about 60 flights on it.
01-14-2009, 12:54 PM
#307
RE: Power Expander or not -that's the question
ORIGINAL: Hammbone
I saw the reply.
Do like I suggested, ask Smart Fly what kind of a voltage drop you will get if you try and pass a momentary current flow of 10 to 20 amps through this switch and through 2 standard connectors.
It doesn't matter if the current flow is constant or momentary, you will just get either a constant or momentary voltage drop to go along with it.
This comes right off of Smart Fly's website:
"We have measured a digital servo, unloaded, drawing 0.6 Amp when kept in continuous motion. Imagine what the same servo is drawing under load and then multiply that by the six to eleven servos you have in the plane. While this may be momentary this is when you need the least voltage drop to the servo as voltage supplies the servos’ torque. Reduce the voltage the servo sees and you reduce the torque the servo can supply."
"We have measured a half volt drop over eighteen inches of 22 gauge wire and one connector at 5.0 amps."
Now if Smart Fly has measured a 1/2 volt drop when passing only 5 amps through 18" of 22g wire and a standard connector, how much more of a voltage drop do you think you are going to get when trying to pass 10 to 20 amps (even if it's momentary) through a 5 amp switch and 2 standard connectors?
Do you want your servos to get good voltage or not?
Why in the world would anyone use a $30 switch that's rated at 5 amps when they could use a $30 switch that's rated at 15 amps (Fromeco Badger switch)?
Why in the world would anyone give advice to a fellow modeler, and suggest that they use a $30 switch that's rated at 5 amps. when they could suggest that they use a $30 switch that's rated at 15 amps?
Jim
I saw the reply.
Do like I suggested, ask Smart Fly what kind of a voltage drop you will get if you try and pass a momentary current flow of 10 to 20 amps through this switch and through 2 standard connectors.
It doesn't matter if the current flow is constant or momentary, you will just get either a constant or momentary voltage drop to go along with it.
This comes right off of Smart Fly's website:
"We have measured a digital servo, unloaded, drawing 0.6 Amp when kept in continuous motion. Imagine what the same servo is drawing under load and then multiply that by the six to eleven servos you have in the plane. While this may be momentary this is when you need the least voltage drop to the servo as voltage supplies the servos’ torque. Reduce the voltage the servo sees and you reduce the torque the servo can supply."
"We have measured a half volt drop over eighteen inches of 22 gauge wire and one connector at 5.0 amps."
Now if Smart Fly has measured a 1/2 volt drop when passing only 5 amps through 18" of 22g wire and a standard connector, how much more of a voltage drop do you think you are going to get when trying to pass 10 to 20 amps (even if it's momentary) through a 5 amp switch and 2 standard connectors?
Do you want your servos to get good voltage or not?
Why in the world would anyone use a $30 switch that's rated at 5 amps when they could use a $30 switch that's rated at 15 amps (Fromeco Badger switch)?
Why in the world would anyone give advice to a fellow modeler, and suggest that they use a $30 switch that's rated at 5 amps. when they could suggest that they use a $30 switch that's rated at 15 amps?
Jim
As far as the voltage drop you are correct. The drop is not good which is why I use 5 cell NiMh. They run above 6 volts so I won't have a brown out issue with mine. They are 1950 FAUP which deliver a ton of current before dropping their voltage. Lithium ions can't supply that kind of current.
I see what you're saying Jim, it's like paddeling upstream posting here isn't it? Don't get anywhere.
01-14-2009, 01:13 PM
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RE: Power Expander or not -that's the question
Like I said, it doesn't matter whether the current flow is continuous or not. If a guy would size all of his components in regards to max or peak current flow, he would minimize his voltage drops.
Are you saying that you're O.K. with momentary voltage drops? Are you O.K. with the voltage dropping at the exact time when your servos need it the most, during peak current flow? If not, then why size your components to minimum current flows?
If any one of your components is rated at "X" amps, and you pass more than "X" amps through it, you are going to get an excessive voltage drop. It doesn't matter if the current flow is continuous or momentary. You will just get either a continuous or momentary voltage drop.
If you pass 10 amps momentarily through a 5 amp switch, you are going to get an excessive, momentary voltage drop.
I am simply suggesting that people size their system for peak current flow in order to minimize voltage drops, and I still don't understand the resistance to doing so.
Jim
Are you saying that you're O.K. with momentary voltage drops? Are you O.K. with the voltage dropping at the exact time when your servos need it the most, during peak current flow? If not, then why size your components to minimum current flows?
If any one of your components is rated at "X" amps, and you pass more than "X" amps through it, you are going to get an excessive voltage drop. It doesn't matter if the current flow is continuous or momentary. You will just get either a continuous or momentary voltage drop.
If you pass 10 amps momentarily through a 5 amp switch, you are going to get an excessive, momentary voltage drop.
I am simply suggesting that people size their system for peak current flow in order to minimize voltage drops, and I still don't understand the resistance to doing so.
Jim
01-14-2009, 01:17 PM
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RE: Power Expander or not -that's the question
seems to me that it would be like driving thier car with the loud pedal spending a lot of time nailed to the floorboards [&:] Nothing can keep going like that witghout breaking somewhere
01-14-2009, 02:01 PM
#311
RE: Power Expander or not -that's the question
ORIGINAL: ricomari
JoeAirPort: What size plane are you using 5cell NiMh batteries on? On the Reciever? Redundant? Thanks.
JoeAirPort: What size plane are you using 5cell NiMh batteries on? On the Reciever? Redundant? Thanks.
I see that you're setting up a 35%. You could just call the guy at Smart Fly and tell him what your ideas are. I'm sure he'd set you up. The ping pong match here will never end.
================================================== ================================================== =================
E-mail from Smart Fly:
Hi Joe,
The switch is good for 5 amps continuous. This is enough for a 40% plane when two
are used. Peak load would be in the 15-20 amp range. You should never have more
than an amp of continuous current on your size plane. A 40% should not have more
than 2 amps continuous current.
At 11:43 AM 12/31/2008, JoeAirPort wrote:
What is the actual current rating of this switch? Some guy on RCU is saying only 5 amps. This switch is perfect for a 50cc aerobat (Extreme Flight Yak and Extra in my case).
Thanks
Joe
01-14-2009, 02:12 PM
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RE: Power Expander or not -that's the question
Guys, I think both sides of the issue have been made over and over and over one more time. Nothing new or positive is coming from the thread so I am going to lock it up.
This horse can't beaten anymore
This horse can't beaten anymore
01-14-2009, 02:12 PM
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RE: Power Expander or not -that's the question
now I am curious, how do you rate continous current on a 40%er ??? it would be rare to have it flying at neutral at any time for more than 2 or 3 seconds flying imac, and hucking or 3d flight will be an even more intense workout on thwe whole system. That link back a couple pages showed nearly non stop spiking over 10 amps and up 17+ and thats for a 35% plane. Tghere were no flat line continous lines for any amount of time worth noticing, and continuous current spikes like that will only heat things up till something fries
