Various projects back to projects

tweeters
Two small tweeters built in a wooden enclosure, meant for "fidelity assistance" for computer speakers

 

Pumping water with electricity

This is what happens when you put current through the two electrodes (stainless steel) through an salt solution in water. The electrodes corrode very fast, leaving a brownish water color (probably a bit toxic due to the metals coming off the stanless steel), The water spins really fast with a strong permanent magnet below the two electrodes (the Lorenz force is responsible for this). Current was around 4 amps, which passed through at 25 volts.

 

Explanation on the working principle of the thermostat in refridgerators

Probably the most common problem with refridgerators is that the freeze part of the fridge is working fine but the cooler part is not cool enough and the fridge does not turn off anymore. it looks as if the thermostat is broken with this kind of problem but mostly it is not. More likely is that there is not enough cooling agent inside the system. Normally there should be enough of this to fill bith the freezer part and the cooler part but if there is lack of it there will be only enough to fiull the freezer an only a part of the cooler. "But now my cooler part is at the right temperature but still the fridge will not turn off" this is the intermediate state, there is just enough cooling agent to reach the cooler part but not enough to reacht the thermostat.
To explain this further we take a look at the thermostat.
This is a device that turns an electrical switch on and off depending of the temperature at the sensor. This sensor looks like a piece of copper wire, but there is some liquid inside that expands or shrinks depending on the temperature. Compare this with a normal thermometer with mercury.

Now this thermostat does not turn off when say 7 degrees celcius is reached, but at a much lower temperature! and it will turn on at at temperature of about 7 degrees. why is this the case: The compressor will work an will punt liquid gas inside the system. this gas will evaporate when it is heated but so absorbing this heat. so the element inside will cool down. this process will go on until the liguid gas has reached the thermostat and cools this to a low temperature (minus 10?) and switches off. then there is still some liquid gas inside the fridge and the cooling will continue. the fridge will cool down a little more then but of course not to minus ten degrees, the element has not enough capacity for that. Now the temperature rises to above the value at which the thermostat is setted and the cycle will continue. so the temperature at the sensor must be much lower than the temperature of the fridge, but that will never happen if there is not enough cooling agent in the system.

Sometines the cooling agent can be refilled, but with the fridges described here the agent is not environmentally friendly enough, so you will have to buy a new fridge.sorry.

 

How to install windows XP without booting windows XP

If it is not already there, put a bootable partition like DOS, windows 95 Windows 98 etc on the existing hard drive.
copy the windows XP installation files to the disk
make config.sys file and put "device=himem.sys" in it 
copy "himem.sys" and "smartdrv.exe" to the root of the disk (download it from internet or from another computer running dos,win95 or win98)
boot the computer
execute "smartdrv.exe" at the dos prompt
change to windows XP installation directory
change to \i386 execute "winnt.exe"

 

MSword paste special, Unformatted Text

Always wanted to assign CTRL+V to paste text only without formatting instead of always using paste special- unformatted text? then do the following:

Tools> macro> record new macro>give a name and press ok> type something> hit stop recording button>. press ALT F11 and replace all code by this:

Sub PasteUnformatted()
Selection.pastespecial Link:=False, DataType:=wdPasteText, Placement:= _
wdInLine, DisplayAsIcon:=False
End Sub

Save to normal and exit the Visual Basic editor.
Tools> customize>Keyboard>choose category edit>choose command EditPaste and delete the CTRL+V shortcut key, choose category macros and assign CTRL+V to your macro.

 

Acoustic decoration plates

These plates absorb acoustic energy, to be used to diminish reverberation. A stylistic effect is added in the form of integrated lights. when the lights are turned off the plates are barely distracting.

Different colors of light are possible. Light effects, such as individual dimming, patterns or color change are optional. Lights can be turned on and off with a switch, remote controlled or by proximity sensing depending on the type of panel.