joco1

ive built a few .40 size planes and ive been looking at bigger planes and a few of the adds on here for rtf models tell about being equipped with 2 switches my question is why or when do you need more than 1 switch

DMcQuinn

My Feedback: (13)

The switch is one of the weak links in your on-board electronics. Switches can fail due to vibration, for example. So many of us use two switches in parallel. For example, I have one battery. I solder two sets of wires from the battery. one set of wires goes thru a switch and on into the receiver. Same with the second wire (thru a second switch and on to the receiver). When I get ready to fly, I turn sw "A" on. make sure the surfaces move. Then I turn "A" off and switch "B" on. Make sure everything is working. Then I turn switch "A" back on and fly. Now I know if during the flight one switch fails, the electricity will flow thru the other switch and all will work OK.

Gasoline engines are probably harder on switches than glow engines (harder vibrations).

You can also use two batteries and gain some redundancy also.

Long ago, people would actually use two receivers also. But this has faded from use since the receivers are so reliable these days. Although the new JR 2.4 gHz receivers can be set up this way.

RCKen

My Feedback: (9)

Here is the setup using two switches and two batteries to get redundancy.

Ken

joco1

thanks, i had no idea about this! so when you do fly both switches are on? and my next question is when do you need a ignition switch i have always flown with glow engines do they ever need an ignition switch and what are regulators used for?

DMcQuinn

My Feedback: (13)

Yes, while flying both switches are on. That way,, there are two independent paths to the receiver. Most people use two batteries as shown above. I use just one battery, but I watch the heck out of it (I have a voltage monitor in the plane that transmits the voltage to a receiver on my transmitter ten times per second with an alarm).

RCKen

My Feedback: (9)

Ignition switches are used when you use a gas engine. You need a switch to disable the electrical on the engine so it can't fire "accidentally".

Ken

ChuckW

I try to put two batteries and two switches in parallel on every plane that has the room and can tolerate the extra few ounces of weight. It is good insurance.

w8ye

My Feedback: (16)

I have a plane with two batteries and two switches

jetmech05

I use 2 switches when I have an on board glow system..1 for the plane and 1 for the on board glow...just like gas..the second switch kills the battery for the glow system

beau0090_99

Joco,
The regulator is used when you run either a Gas engine or glow engine and you want to use Lipos for your power. Since the nominal voltage per cell for these are 3.7v, there isn't a combination of number of cells per pack that would equate to 4.8v or 6.0v to work with our more common and older Rx's(Newer ones are now allowing 7.4v range). Also, since most gas engines do not incorporate a magneto (way of generating their own power for spark), they use an external battery pack for charging the coil. A couple of reasons to do this include the reduced electrical noise generated by a Magneto, and also the reduced weight of the components (flywheel, pickup coils, etc.)
Hope this helps,
Curtis

Gray Beard

My Feedback: (-1)

I also have A 6 volt sub C battery in one of my bigger planes that has two wires so I can run one big battery with two switches. I'm also running A Zenoah gas engine with A Magneto and I run A switch that grounds out the electrical system to kill it just in case there is A problem with my radio or my holder has to kill the engine in case of an accident or other problems.

AstroDad

I do the same thing even with my 40-size glow plane. my buddy who totaled his Pulse due to a weak battery still insist on flying with only a single battery.

These 2.4 GHz recievers are quite sensitive to voltage drops. Two batteries makes a huge affect on keeping the voltage good.

RCKen

My Feedback: (9)

As a clarification on this. It is only the JR/Spektrum equipment that have had issues with voltage. Futaba and Airtronics have set a much lower cutoff voltage in their equipment and don't have issues with voltage that JR/Spektrum does.

Ken

CGRetired

My Feedback: (1)

One more thing. I use a pair of 6 volt (5 cell) NiMH 1200 mah packs in all my larger planes.. larger meaning anything 60 or larger. I also use a single 6 volt pack on smaller planes. The reason I do this is because I am using the Spektrum DX7 radio and consider it "insurance" to have the 6 volt pack so that I don't go near that re-boot threshold that caused problems in the past.

I know.. it's been fixed. However, I still use the 6 volt packs.

As Ken pointed out, each battery has it's own switch wired as shown in his diagram. This puts the battery packs in parallel. If one should fail (personal experience with that, by the way), there is always a second one there to complete the flight. I never even realized there was a problem until I landed and checked the voltwatch. So, I also use and endorse Voltwatch. I always know the status of my battery(s) before and after every flight. Any indication of a low voltage sends the battery packs to the charger. No if-ands-or-buts about it. Simple enough, and I believe, a good policy.

CGr.

w8ye

My Feedback: (16)

When you have two NiCd or NMH battery packs, it is desirable to charge them separately. If you try to charge them parallel together, the first one to peak voltage will shut the peak detector type charger off. So I charge them independently.

Jetdesign

My Feedback: (8)

A little more on regulators...

A 6 volt battery when fully charged will actually put out over 6 volts. This can cause some 'twitching' with certain receiver/servo setups. A regulator will prevent that from happening.

You can also get regulators that are adjustable, say for 5.5 volts. You can use this with a 6 volt battery so you know you are getting the same strength out of your servos from the beginning to the end of the day. Servos put out a certain torque associated with the amount of power being delivered to them. Unregulated systems will have servos that are stronger and faster at the beginning of the day, and slower and weaker at the end of the day.

Using 2 cell lipos, you can set the voltage to 6 or 6.2 volts to get the maximum power and speed out of your servos, and be sure that you have the same strength and speed for every flight.

w8ye

My Feedback: (16)

On my gas engines with the C-H battery powered ignition, I use a 4.8V set up just like with the radio but it is kept up front and charged separately

joco1

thanks guys for the great info on this ,i learn something new on here every time i look!!!!!!!!!

dignlivn

I too use 2 4.8 batteries as in Kens diagram.
Some members of my club don't agree with
me, but after losing my trainer to a 1 battery
setup, I have not had any Problems (KoW).

I'm trying to learn more about what Regulator
is most reliable ??

Bob

Jetdesign

My Feedback: (8)

I don't know what makes one better than the next other than wire gauge, etc, but tech-aero.net is where I'm getting mine. They are made by an electrical->computer engineer and used widely in the pattern community (which demands the best in reliability). Lots of options for redundant batteries and charging ports, etc. I've met the proprietor too, he's a good guy and I'm more than happy to give him business

http://www.tech-aero.net/

CGRetired

My Feedback: (1)

Thanks for the info, but I don't (never have) charge them together. I don't think I said that in my post.

CGRetired

My Feedback: (1)

I've been using 6 volt packs, fully charged when starting, and have never.. never.. had servo twiching. Six volt packs have been in use for years now with no real issues. Most receivers and servos are designed to operate with 4 or 5 cell packs.

Regulators are not necessary in most applications and actually produce another point of failure in a power system that is already vulnerable. They should be used only in applications that really need voltage regulators.

Talk to any experienced pattern person and they will tell you that basic is good. Simple is best.

In addition, I fly 5 or 6 flights with a standard 6 volt (5 cell) pack setup, either parallel (two packs) or single. That's with NiMH packs. If a pilot monitors the battery voltage, as I said earlier (using voltwatch for instance), you can keep a close watch on the packs and either swap them out or recharge with a field charger (about an hour of recharge time). I have never "pushed the envelope" for battery power. I don't think it's worth taking the chance. It's better to stop when you realize it's time to stop and recharge or change battery packs, fly a different plane, or go home. Easy as that. Regulators, LiPo's, not needed for most of our flying.

Now, when you get to the larger size with gas engines, well, I don't fly them, never have, so I don't really have an opinion or a recommendation for those. But, I've seen both regulators and LiPo's in those type planes, but, for the average person out there flying RC for sport, it's not worth the expense to use either.

joco1

do you need 2 voltwatch meters when you have 2 batteries or is 1 enough for both?

w8ye

My Feedback: (16)

The way the Voltwatch is normally hooked up it will read what ever voltage is at the receiver. It plugs into the receiver. It is not a pass through device

DMcQuinn

My Feedback: (13)

One voltwatch will show you the condition of the battery system. When both switches are on, the voltwatch sees the composite result of both batteries. If you had two voltwatches they would both show the same thing. With one voltwatch, you can just turn on one switch to see the condition of that battery. Then turn that switch off and turn on the other switch to see the condition of the second battery. turn on both switches to fly.