Wild ducks project/Steam Duck

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Steam Engine

File:Wilescod22.jpg
The Wilesco D22 Steam Engine

We came up with the idea to run the Wild Duck off a steam engine powered generator. This would be fun thing to do, but probably doesn't prove that much.

For a more fancy configuration, we could later try to control the steam engine using Symbian's power management.

We investigated what was needed to steam power Wild Duck. The power calculations done by Arunabh and Arnaud were useful in this.

From a discussion at the Unofficial Mamod and other Steam Engine forum, we were referred to a guy in America who makes steam engine generators.

The producer of these engines, Peter Santa Maria said:

I dont have one so I can not test it before sending it to you. I currently build a generator that produces about 50V and 200 mA for $85 plus shipping. Europe I do for $17. regular mail or $31 priority mail. I have those available in the configuration you see on EBAY. I have materials required to build one like the canadian has. That one generates 25V and about 300mA, the price on that one is $175 just because I had saved these materials for building my own personal generator someday and I will NEVER be able to find them again.

As far as the engine is concerned I believe you could use any of the large wilescos D18, D20, I would recommend the D24 because of its larger boiler. I understand what you are trying to do... the merging of an old technology with modern electronic devices.. so I can imagine that you want to have so flame visible to underline the contrast but you may consider the electric heated steam engines as they deliver more heat and therefore more sustained power than pellet fired ones.

The steam engine we can most reliably source is probably the Wilesco D22 (see photo above).


Power Usage

One of the main concern is to be able to supply enough power to allow the system to run without any risk of shut down due to a peak of current when making a phone call.

Here are few considerations to take into account:

  1. The Beagle board can be powered by USB that means
    1. Voltage = 5V
    2. Current = 500mA
    3. Max power available is: 5V*0.5A= 2.5W
  2. The modem is powered by a regulated AC/DC adaptator that means
    1. Voltage = 7.5V
    2. Current = 2A
    3. Max power available is: 7.5V*2A= 15W

We are not too concerned about the power necessary to run the Beagle board because we are not expecting to do something that requires too much power.

Our concern is around the modem when we are doing some phone calls.

AA & AL have been doing some tests on the modem to measure the current used. For that we have been using a basic multimeter to measure the current. On the modem, remove the jumper JP10 (open connection to put an ampermeter) that is close to connector we are using to plug the power and put the multimeter probes on each side of the connector to allow current measurements.

Here is the result of our measures that will give us an idea of the current used by the modem in different cases:

Table 1: Modem power usage
Activity Current (mA) Power (W)
Bootup 384 2.88
AT 206 1.545
AT+CREG=? 174 1.305
AT+CREG=1 216 1.62
ATD077713768XX; 376 2.82
ATH 170 1.275
Idle 175 1.3125

Notes:

  1. Formula used to calculate the power: Voltage in V * Current in A = Power in W
  2. As we are in town, the base station are not too far, which means we didn't need so much power for the call. Now if we are far away, that could have an impact. The network infrastructure at the MWC (due to the type of event) should have few base stations not far away, which means that we should be in similar conditions of what we have just done.
  3. The measures for the current where done with a simple multimeter and looking at the LCD to note the value, therefore they are not very accurate, but they should give a good idea of where we are in terms of power.

The conclusion of this test shows that we reach the peak of current at boot up and in call.

The maximum power was less than 3W

Of course we will need to do something similar for the Beagle board and for the full hw implemenation when we will have something working, just to make sure that the steam engine will be able to cope with the power necessary to run the setup.

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