How to build power expander

[spoiler-man]

Has anyone ever thought about building a power expander? Couldn't you use the 3pin deans connectors and build a simple expander to where that you would't need any y-connectors? It looks like a trip to Radio Sack and a few dollors this could be done.

[IMACmike]

no, but I would like to see someone come out with a heavier gauge wire (14ga?) extension so there is less voltage drop due to small gauge wires on long extensions going to the tail and wing tip end servos on large (35% - 40+%) models. I know that there would be a slight weight penalty, but the servo power would be worth it. Anyone have any ideas on that??

[yakwrecker]

Ive done it. Its so simple its stupid. All you need to do is make the red and black lines go strait to the power and have the white(signal) go into the RX, then set up a branch line to power the RX. So the only thing that will have black and red on the RX is the power input and the rest are signals. I posted a pic of mine before but i cant find it. Like i said its very simple.
Jon

[BR289]

I would like to see that pic just out of curiosity....

[spoiler-man]

I would like to see the pic also. I was thinking about using the 3pin deans plugs on top of the board and for the red and black feeds maybe using a large brass or copper wire. Then bring the white wire to the receiver. It looks like it would be simple to make and you could use 2 battery feeds. Do you think there is a need any type of filters in the system when using 72?

[JimC-MD]

Here is some interesting information for you to look at.

You can look at the length of the run to where the servos are located. You can enter the wire size and the input voltage (6VDC) and the peak load you expect. It will then calculate the percentage of voltage drop and the available voltage at the end of the circuit.

For an example, if you use 22AWG wire (heavy duty servo lead size) and a run of five feet with a load of 5 amps you will see that the voltage will drop by .83 volts or almost 14%. The supply voltage would drop to just over 5. This would slow and weaken a servo from its 6V specs.

If you were going to build a power distribution system to provide power to the model in modular sections, (which it sounds like you want to) you should run some calculations for the main wire sizes. If you run a +- circuit back and do not size it correctly, you may as well just use the long 22AWG leads.

I hope this helps
http://www.bdbatteries.com/wirerules.php

[JimC-MD]

Another interesting thing to think about. If you use a five foot lead and a three foot lead to a wing (as an example) the voltage supply under a max load of 5 amps would be less at the longer end. The variation would be about .4 volts. It does not seem like much, but we go to the trouble of trying to match these things up and then allow a supply variation.......

[KIM]

jim thanks for the info and the web site did i say that

[Pittsflyboy]

	Quote: Originally Posted by IMACmike
	no, but I would like to see someone come out with a heavier gauge wire (14ga?) extension so there is less voltage drop due to small gauge wires on long extensions going to the tail and wing tip end servos on large (35% - 40+%) models. I know that there would be a slight weight penalty, but the servo power would be worth it. Anyone have any ideas on that??

Servo City has 14Ga wire.

[Rolling Thunder]

Jim Oddino, "radio control pioneer" built his 2.6 extra a couple of years ago with a voltage regulator at each sevro. It worked very well. No signal bufflering but great power to each servo.

[spoiler-man]

Here is what I am basically talking about just a simple expander with 2 batt. connections outlets are 2 for each channel and 3or 4 for the rudder.

[airbornrc]

Servo city sells an eight channel kit for less than you can buy the parts for. I used one in my 35%. I soldered the extensions directly to the board with no connector so only one plug between the servo and power.

Mark

[martinarcher]

	Quote: Originally Posted by Pittsflyboy
	Servo City has 14Ga wire.

Got a link? I browsed their site and the heaviest I found was 22AWG. I also would like to go big on the gauge of the longer runs.

Thanks!

[Pittsflyboy]

	Quote: Originally Posted by martinarcher
	Got a link? I browsed their site and the heaviest I found was 22AWG. I also would like to go big on the gauge of the longer runs. Thanks!

Go to:http://www.servocity.com/html/high-amp_wire.html

[spoiler-man]

Go to your local hardware or auto parts store for standed 18 to 12 wire for 12v, should work the same. I looked at some today 2.39 for a 30 ft roll. I also found some 3pin deans at the LHS now to get a piece of circuit board and I am ready to start building the power board.