Search found 11 matches

by Washout661
Tue Jan 25, 2011 6:55 pm
Forum: Off topic forum
Topic: How to build an electromagnet
Replies: 15
Views: 6935

Re: How to build an electromagnet

optocoupler (might also be called an optoisolator) is like a relay, but is solid state. Uses a light source on one side to control current flow on the other side. Seem to have lower power requirements than relays /solenoids but I've never had the opportunity to use one.
by Washout661
Tue Jan 25, 2011 12:36 pm
Forum: Off topic forum
Topic: How to build an electromagnet
Replies: 15
Views: 6935

Re: How to build an electromagnet

You will be severly limited by the voltage / current available. If the max current available is 70mA, and your mac voltage available is 1.75V, you will be limited to 24 ohms resistance in your system. This doesn't give you much to play with when building your circuit. Have you thought about using a ...
by Washout661
Wed Jan 19, 2011 12:39 pm
Forum: Off topic forum
Topic: How to build an electromagnet
Replies: 15
Views: 6935

Re: How to build an electromagnet

Force = ((N x I)^2 x k x A) / (2 x g^2) N = the number of turns in the solenoid I = the current, in amperes (A), running through the solenoid A = the cross-sectional area, in meters-squared, of the solenoidal magnet g = the distance, in meters, between the magnet and the piece of metal k = 4 x pi x ...
by Washout661
Wed Sep 29, 2010 11:54 am
Forum: Tools and Construction
Topic: 2D PJ Pressure analizer
Replies: 25
Views: 11992

Re: 2D PJ Pressure analizer

How realistic would it be to use 3 separate images as inputs to set the initial conditions? eg 1 each for initial pressure, temp & velocity. Separate outputs for each of these could be much easier to interpret for analysis. Also, if you are looking at importing in RGB for pressure & temp, would it b...
by Washout661
Mon Aug 16, 2010 12:07 pm
Forum: Jet Vehicles, All Types
Topic: Self launching glider packs a retractable jet engine
Replies: 2
Views: 2653

Re: Self launching glider packs a retractable jet engine

Being a fairly experienced winch launched gliding instructor, the idea of carying a retractable 'power pod' is always interesting, but I don't see the benefit of jet vs piston power. The speeds & altitudes flown at don't offset the massive difference in fuel consumption. Whilst it will obviously loo...
by Washout661
Wed Apr 08, 2009 11:50 am
Forum: Gas turbine forum
Topic: Parallel Spool engine - Has this been tried?
Replies: 3
Views: 2420

Parallel Spool engine - Has this been tried?

Most DIY engines are single spool, whether using cetrifugal or axial compressor/turbine. Twin spools are probably out of most 'normal' peoples ability due to the level of complexity involved as they require concentric shafts for the inner & outer stages. Has anyone ever tried using 2 completely sepa...
by Washout661
Wed Sep 17, 2008 6:27 pm
Forum: Off topic forum
Topic: Something I Suspect But Can't Prove
Replies: 7
Views: 2437

Re: Something I Suspect But Can't Prove

Putting my rusty physics head on again... Question 1, is it a standing wave or a travelling wave? This is a difficult one because of the relationship between the speed of the travelling wave, the desity of air which also defines this and the frequency and wavelength. Change one, and the others tend ...
by Washout661
Wed Sep 26, 2007 1:02 pm
Forum: Off topic forum
Topic: A steam generator with possible over unity
Replies: 32
Views: 16214

A steam generator with possible over unity

Could this be the effect of releasing energy stored in the water molecule? ie electrons dropping to lower energy levels within the atoms. This could be analogous to the HeNe laser where one atom is excited by RF and then passes the energy by collision to the other which emits at the appropriate freq...
by Washout661
Tue Feb 27, 2007 1:52 pm
Forum: Gas turbine forum
Topic: Johansson´s Pocketbike
Replies: 431
Views: 217674

Throttle lag - potentially daft idea

Would it be possible to connect a pressure release valve actuated by a solenoid to release excess fuel pressure when closing the throttle? Using a microswitch which is pressed when the throttle linkage is closed, momentarily actuating the solenoid and realeasing some fuel to allow the pressure to dr...
by Washout661
Fri Jan 26, 2007 12:58 am
Forum: Valveless pulsejet forum
Topic: New and Improved Lady Anne
Replies: 179
Views: 64003

Lady Anne

Larry Just a thought from an outsider trying to grasp at the concept of the engine... As far as I understand it, you are modelling the design of the engine based upon open ended pipe resonance in order to get favourable pressure nodes & antinodes to aid in the flow of gases through the system. Somet...
by Washout661
Fri Nov 17, 2006 1:05 pm
Forum: Off topic forum
Topic: Thrust without reaction mass?
Replies: 15
Views: 6557

re: Thrust without reaction mass?

Conservation of momentum, ie like torque reaction in a helicopter, recoil from a rifle / shotgun. By stopping the wheel, you are unbalancing the system so the vehicle moves in order to conserve momentum.... but then I finished uni a good few years back now so I could be wrong.... only taken me 6 mon...