Need help with circuit to delay reed switch triggering transistor.

[Inquorate]

thinking about it

I suggest reading the veljko milkovic oscillator violates 3rd law of motion thread, dr lindemann's how-to manual, see veljko milkovic's site and watch the videos. and build a small one for practice that is adjustable. Make it out of wood, drill lots of holes, use skateboard bearings after stripping the lubrication and replacing with sewing machine oil. 1/4 inch diameter bolts fit straight into the bearings (there's 8 in a skateboard) Getting the pendulum and lever in sync is an art.


@ all - is there a way to change the title of a thread. I'm thinking 'gravity mill'

Love and light

[Inquorate]

Circuit dramas

After having difficulties with the delay circuit, I'm going to take gyula's advice and use a 555 timer circuit.

I found this page

LM555 Timer Circuits

And will be trying this circuit tomorrow, with a 1 m ohm pot for fractions of a second. And hopefully it will be a square wave 'off' so I can get rid of the relay.

http://home.cogeco.ca/~rpaisley4/LM555Delays1.GIF

Love and light

[gyula]

Hi Inquorate,

I have to tell you life is not easy even with the 555 circuit you pointed at...
I have not considered seriously that your magnet will trigger twice: first at upswing and then again at return. And if you place the magnet just near to the apex then the reed may be kept ON for the time the pendulum is coming up and down to and from the peak. Maybe it is possible to tweak the distances by placing the reed further out from the course of the bob but even so the output pulse from the above circuits can be too wide to keep the electromagnet ON for unnecessary long.

So you would be better off if you could control the delay and the ON-time of the switch independently. And the circuit for this needs two 555 chips and the schematic is just under the Delayed recovery and negative recovery circuits you pointed at, entitled Two Stage Time Delay Circuit.

The first 555 (named A) makes just the delay time and the second 555 (B) determines the width of the output pulse that comes out after the delay. By making this output pulse as narrow as possible you can reduce the current consumption of the electromagnet to a certain degree (depending also on its main job needed of course). Of course if your single 555 monostable is good for your task then you do not need this two stage circuit.

I found two interesting links when you have time to go through, they maybe are some food for thoughts with respect to this topic.
The first is a circuit for a pendulum clock: http://www.geocities.com/~uwezi/elec.../pendulum.html
and the second is just a control of a pendulum with an electromagnet:
Arduino Perpetual Motion Machine (Pendulum)- aHT8pendu

rgds, Gyula

[Inquorate]

Dual 555 timer relay delayed switch on and pulse length circuit

Here's one video. I'll post the other link when it comes live

YouTube - pendulum push coil tuned up

[shlodo]

doog stuff mate

Here's one video. I'll post the other link when it comes live

YouTube - pendulum push coil tuned up

Great work mate, coming along nicely!

there's something about the pendulum. In theory it should be a perpetual motion machine
The potential energy is created by lifting pendulum, turns into kinetic back to potential. Minus air resistance. i like this design coz it seems that the large wieght on the other side is independant of wats happening in the pendulum.

All u have to do is negate air resistance. An object will travel in a direction forever unless a force is aced upon it. Wouldnt a piece of space debris flying in space forever be perpetual? of course until in smashed into something.

I wonder if the pendulum would go on forever in a Vacuum with no air resistance??

Inquoret, you will be losing energy in the bearing. Ever thought of using a wire/string... its more efficient

Good luck with it, ill be following this space! Wish i wasnt bogged down with uni, I'd build one myself - cant wait 4 holidays! Although we are studying pendulums ATM, will have to pay attention in that class!

-shlodo


EDIT: Lol! i meant to say GOOD stuff mate, not DOOG!

[shlodo]

pickup coils

As well as catching the radiant in that pulse coil u could have pickup coils along side the pendulums path.

Obviously Lenzs law would cause drag. anyone know how to make Lenzless coils?? im sure with thinnner wire it would help, only let voltage and little current through.

my thoughts anyway
-shlodo

[Inquorate]

Lenzless coil

@ Dodo I recently made comments in bedini sg thread or bedini self runner thread regarding a grounded coil (one end) with magnet passing very quickly over it... Other end of coil has neon to charge battery positive. Collapsing magnetic field should still produce radiant spike if use neons. many tubes of hollow metal in core to reduce drag. No Lenz's law as no current until voltage spike thru neon.

All theory so far.

Next video uploaded

YouTube - crazy purple flash staccato

YouTube - pendulum push coil tuned up

These videos are relevant to many discussions I've had on different threads. Hope no-one minds me cross posting :-)

[sucahyo]

Have you ever try to use the principle of joule thief? The transistor base is being activated by revert current.

The implementation to your pendulum would be by making the current generated by passing magnet attached to pendulum to activate the transistor. The delay timing can be done by placing the detector/activator coil in slighly later place than the pendulum mover coil. You can use two detector/activator coil with diode if you need to push to both direction.

This only work if the magnet or coil can generate voltage high enough to activate transistor.

The image just for illustration. Use the principle of current will pass between collector to emittor if there is voltage between base and emittor. connect the detector coil wire to the transistor base and emittor. Use two diode in each detector coil to make it detect only one direction.

[Inquorate]

Sucahyo

I investigated that, but at top of swing, magnet moves so slowly that barely got milliamps. Someone else may have different results though.

[sucahyo]

I investigated that, but at top of swing, magnet moves so slowly that barely got milliamps. Someone else may have different results though.

Can't you place it at bottom?

[Inquorate]

At the bottom

Yes, I made a pendulum with a coil at the bottom. But then I thought we don't push someone up at the bottom of swing on a swing. We push down / across at the apex. It's more efficient, as all the force transfers in the direction of travel.

also, pushing the pendulum up would interfere with the motion of the lever; just when the centrifugal force is pulling the pendulum side of the lever down, pushing it up would detract from this force..

Not to mention the difficulty of getting the pendulum to pass close to the coil, remember it is also going up and down.

I have had to move my coil for similar reasons posted here previously.

Just my opinion though, I may be wrong

[sucahyo]

I see, I forget the the pendulum is moving up and down too.

[Inquorate]

Up and down

Easy to miss, Sucahyo. I built one, got it in resonance and watched it for ages, pushing the pendulum. Then I put the coil in and watched it move (when I finally got the timing circuit worked out) but without the up and down.

When I took the clamp off the lever and everything clanked to a quick stop... Well, quite humbling.

I'm putting the coil on the lever, pendulum side and pushing a part of the pendulum that extends above the lever. More time to push the pendulum which was a problem; weighted pendulum gets out of electromagnet's range really quickly.

So the time the electromagnet is on will be quite a while, methinks.

So, another adjustable 555 timer circuit will be added to pulse the coil off/on/off/on instead of oooooon. That way, radiant spikes can be harvested, increasing efficiency.

[sucahyo]

I see. Placing the circuit at the pendulum holder is out of the question too?

[Inquorate]

Pendulum holder

I'm not sure what you mean by 'pendulum holder'. Do you mean the pivot point from where the pendulum swings???