Monday, November 28, 2011

Beta of the Electron eata goes like a bought one!

Here she is!  And she's running like a beaut.
Here's a pic of the mercury switch...It now only switches a transistor on and off instead of switching the actual current load that energises the coil. But there is 2 advantages to that. 1 is that I can alter the amount of current that energises the coil with the use of a variable resistor...instead of having to add or subtract windings on the coil, and 2, when the mercury switch was carying the full current load, it was sparking inside and carbon from the 2 electrodes was coming off and blackening the glass. I put a tissue behind it so you can see the switch better...
Here's the transistor with standard resistors...Yeh I know it looks bodgee!
Here's how the mercury switch works...below...
There are 2 systems, the drive system and the time system. What the mercury switch is used for is turning on and off the coil(red thing at the bottom right), which impulses the pendulum and keeps the clock running.

In the first picture below, the pendulum (vertical bit on the right) is swinging from right to left, and the small horozontal arm has caught on of the teeth and is turning it anti clockwise. This action will eventually bring one of the cam lobes around on the black wheel, which will tip the backwards shaped tick arm, which then tips the arm that the mercury switch sits on. It works just like the points in an old cars distributer, because it only impulses the pendulum on and off at a time and duration determined by the shape of the lobe.

Here's how the time keeping system works. Each swing of the pendulum makes the horozontal arc shaped arm (below) catch a tooth on the small count wheel, which slowly tuns the black snail shaped wheel (it takes 1 minute to do one revolution) While the snail shaped wheel is turning it is lifting the black horozontal arm which is resting on it. There is a clear arm hanging from the black horozontal arm and it is lifting a tooth on the large count wheel.

When the snail wheel completes a full revolution, it drops the black arm and the arm clear arm hanging from the black arm drops to pick up the next tooth on the large count wheel.
Below you can see the vertical clear arm enguaged with the large count wheel. The large count wheel has 60 teeth for each minute of the hour. Sorry for the ugly bits of bluetack, but their needed for adding weight. It is a prototype afterall...
Hope you like the pics, I'll put a video up of it soon. It looks great when it's in motion!
cheers
rosco

Monday, November 7, 2011

Beta of the electron eater!

This is (I think) the final design to be made into the production model. Everything in flouro green (including the red and purple count wheels) has been altered because of design shortcomings discovered with the 1st prototype!
The red and purple count wheels went to the dentist to have their teeth reshaped so that the the backstop and pulling arm (respectively) fell into the wheels, not leaving a recess for backlash to occur. (see top right and bottom left yellow bits)

The face no longer supports the centre shafts, as it created too much friction of there was a small amount of twist in the clocks chassis. The new face design looks better too!


There have been 2 lobes added to the cam wheel (above), to make a total of 3 lobes. This will make the impulsing circuit energise the coil every 10 seconds, instead of every 30 seconds. I think that should be enough to keep it running. Only a long run like for an hour or 2 will tell, and I am yet to install the 3 lobe cam into the 1st prototype to see how it goes. Here is what the 1st proto type currently looks like...
I don't like the all black, it was just easier to cut all of the pieces in one cut. When this was first assembled, I wasn't feeling that is was going to all that successful. With the new mods made to the design, I am really confident that its going to run well! Fingers crossed.
cheers
rosco

LATEST UPDATE...
I think I am going to try a Mercury Switch!
Here is a design that could work. The mercury switch is the spaceship looking thing mid left. The long arm on the lever is to amplify the small lobe on the on the cam. We'll see