ibanezmatt13

[16:18] <eroomde> yes
[16:18] <eroomde> but
[16:18] <eroomde> have the battery locally
[16:18] <eroomde> and use a relay
[16:18] <eroomde> don't try and send all the current down 100m of cable
[16:19] <eroomde> you get huge resistive losses, or massively thick heavy cable to get around it
[16:19] <eroomde> also have an arming key switch :)

ibanezmatt13

int IR_Led = 13;

void setup()
{
  pinMode(IR_Led, OUTPUT);
  digitalWrite(IR_Led, LOW);
}

void loop()
{

ibanezmatt13

miniITX
http://www.netmf.com/gadgeteer/what-is-gadgeteer.aspx

ibanezmatt13

A cell in a hearing-aid supplies a current of 2.5mA through a resistance of 400 ohms. When the wearer turns up the volume control, the resistance is changed to 100 ohms and the current increases to 6.0mA.



1. What is the E.M.F and the internal resistance of the cell?

2. What is the maximum current the cell could supply?

ibanezmatt13

0.1 0.40197625 4.0197625 0.007625
0.2 1.20610063615 8.04124386152 0.0248136152447
0.3 2.41264374813 12.0654311198 0.051872582644
0.4 4.02197510838 16.0933136024 0.0888248264878
0.5 6.03456349865 20.1258839027 0.135703003013
0.6 8.45097738455 24.164138859 0.192549562778
0.7 11.2718854388 28.2090805424 0.259416833593
0.8 14.4980571643 32.2617172548 0.336367124293
0.9 18.1303636182 36.3230645398 0.423472849697
1.0 22.169778239 40.3941462075 0.520816677202

ibanezmatt13

import numpy
import matplotlib.pyplot


x = []
y = []


gravitational_acceleration = 9.81 # m/s^2
time_step = 0.1 # s

ibanezmatt13

$$NORB_Test,0,100628,53.530376,-2.717098,104.0,1,1,4,2.80,23.50,54.06
$$NORB_Test,1,100645,53.530354,-2.717046,109.9,1,1,4,2.76,23.55,53.78
$$NORB_Test,2,100702,53.530357,-2.717031,113.0,1,1,4,2.73,23.57,53.57
$$NORB_Test,3,100719,53.530346,-2.717078,108.2,1,1,5,2.78,23.55,53.69
$$NORB_Test,4,100736,53.530357,-2.717082,106.2,1,1,5,2.77,23.49,53.62
$$NORB_Test,5,100753,53.530373,-2.717090,105.8,1,1,5,2.85,23.47,53.40
$$NORB_Test,6,100810,53.530388,-2.717082,105.7,1,1,5,2.66,23.53,53.88
$$NORB_Test,7,100827,53.530396,-2.717080,105.7,1,1,5,2.74,23.54,53.88
$$NORB_Test,8,100844,53.530396,-2.717083,105.7,1,1,5,2.87,23.52,53.84
$$NORB_Test,9,100901,53.530380,-2.717097,105.7,1,1,5,2.85,23.59,53.95

ibanezmatt13

import numpy
import matplotlib.pyplot


x = []
y = []


gravitational_acceleration = 9.81 # m/s^2
time_step = 0.1 # s

ibanezmatt13

# PROBLEM 1
#
# Modify the orbit function below to model
# one revolution of the moon around the earth,
# assuming that the orbit is circular.
#
# Use the math.cos(angle) and math.sin(angle) 
# functions in order to accomplish this.

import math

ibanezmatt13

[09:46] <ibanezmatt13_> Hi Ed, love the scope, it's awesome! :)
[09:46] <eroomde> great!
[09:46] <eroomde> they're a great tool
[09:47] <eroomde> hope it helps you do more cool things
[09:47] <ibanezmatt13_> yeah. My Dad's getting more and more keen on the rockets too. H'es instructed me to look at the biggest rocket we can get before level 1 certification :P
[09:47] <eroomde> ha!
[09:48] <eroomde> well, probably D motors
[09:49] <eroomde> those are the largest black powder ones (the solid fuel that you can just guy off the shelf)
[09:49] <eroomde> before you get to AP (ammonium perchlorate) that the bigger stuff uses
[09:49] <ibanezmatt13_> that sounds like a start