First off Firemylaser amazing build here. Ive nearly finished a version similar to your original but hit a bit of a snag. Im using PWM to controll the motors but I have a bit of a problem with the circuit I chose to use. Found at DPRG: A Simple PWM Circuit Based on the 555 Timer.

I built my system using a common ground and differing positive leads so I tried to remove the Mosfet. One of the attached pics. The circuit works perfectly fine with a multimeter but fails when attached to a motor, guessing the 555 cant generate the correct current. So is there anything I can do to use the positive output pulse to create a positive pulse with the current that the motor needs?

Isn't that what transistors (like the MOSFET is one) are for?

You can't use the discharge output from the 555 IC for drive directly a motor ..... it's not a power output, it's just an open-collector pin for discharge the timing capacitor, and don't have the needed current too.

Use a NPN transistor or a mosfet as power stage ..... if you want to keep that circuit (that is basically my old PWM driver, but drawed incorrectly), and a simple transistor, disconnect the motor from the IC, connect the collector of the transistor on the motor, and the emitter to GND (the pin marked -V motor must be connected to the positive, too, not to the negative), then connect the base of the transistor where you had the motor connected before, through an 1Kohm resistor (left the 10 Kohm one connected to the IC pin, i mean, and from there go to the base of the transistor with a 1 Kohm resistor) ..... be sure that the transistor can hold the current needed from the motor, too, and if needed, heatsink it.

Also, remember that motors generates spikes and disturbs ..... connect a capacitor in parallel to the power supply, another capacitor, say, 100nF, in parallel to the motor, and a diode between the emitter and collector of the transistor, with the cathode on the collector side (motor wire) and the anode on the emitter side (GND).

This way it must be ok.

Okay so after a little digging around I believe I have found the answer to my problem. I believe this setup with the correct safety capacitors in place would do the trick. Correct me if I wrong haha.

That LED lead structure is pure awesomeness! Congratz! All that contacts, you're a genius
When I saw the video, I was like "MUST DO IT"
So I started thinking about how I could build my version of this, and decided to start from the core: the 3 LEDS+contacts and the central motor. And I failed hard.

I already have an idea for the other 2 axis contacts, but the center one, from the motor to the leds, i just cant think of anything good...

I made 2 circular PCB, one for the negative side, the other positive. The positive one I made a triangle of copper in the center, with resistors as the bridge to the LEDs. To extend the axis of the motor (a PS2 controller motor btw) I used the transparente tube from a pen charge. Finally, a coil spring (also from a pen) on both sides of the PCBs, with a wire connected to it (positive and negative)

So when the motor is running, tube+pcb are spinning, and the spring is statical and making contact with the pcb, resulting in a circle of spinning leds!

All good in theory, but the springs kept the motor from spinning

Any suggestions on how to make that contact?

Thanks! x)
http://img828.imageshack.us/i/dsc05865n.jpg/
http://img30.imageshack.us/i/dsc05866g.jpg/
http://img838.imageshack.us/i/dsc05870.jpg/

PS: you can see 2 motors here, but only the top 1 is functional, the other is just for counterweight and support. the springs go between the motor and the pcb, around the plastic tube.

if your having trouble with led's and getting the correct voltage and whatever, i suggest you get a jay car catalogue and theres a whole page with the specs for each type of led and how to calculate the correct resistors for them.

if you cant get one, heres the formula for finding the resistor needed:


Resistor= ( (Voltage source)-(Voltage drop of LED) )/(current draw of LED)

or in other notation;

R= (VS-Vf)/If

if you dont know the voltage drop and the current draw of the led you can just ask whoever you get them from and they should know

Oh no, I'm doin fine with turning the LEDs on, my main problem is how to make the slip contact

@Hardwired101: Uhm, i mean, more like the attached one (i have also a more stable version, but for a motor, this must be ok)

sorry yeti, that was directed @13579 from the last page but it must of posted later or something and for an answer to your question, try using only one spring and use the axle of the motor as the other contact in a sorta slip ring fashion. that way there shouldn't be so much force on the motor then.

A question for HIMNL9 about that last circuit diagram you posted, I get all the symbols you have used except for the one directly right of the 100 ohm resistor, it looks like 3 way switch but not quite sure what it is.

also, another general question. if your using a 470nf capacitor or similar, will it affect the circuit if you use a 100v capacitor when it only a 12dc circuit?

@ louige555: it's an N-channel mosfet

You can use a transistor, if you don't find a mosfet ..... just use one that can hold the current required from the motor, or also better a darlington (remember that under effort the motor current can be much more high than in free-running) ..... any "universal" npn darlington is ok, like TIP120, TIP121, TIP122, and so on.

If you decide to use the transistor in place of the mosfet, just connect the base to the 100ohm resistor, the emitter to GND and the collector to the motor.

thanks a dozen HIMNL9, probs gonna use a transistor as dont know many places to get a mosfet but defiantly set on using one now.

Thanks for the advice HIMNL9, Gona take a crack at this tonight. Hopefully new pics to follow soon.

@louige555

oh, sorry xP
imma try that later

Alright new development and a new problem. So I got both pwm circuits working perfectly (diode included pointing at positive) but when I tryed to fire up with the larger motor it worked for about 10 seconds and then the mosfet burned up. I was trying various resistors to attain the voltage I wanted at the motor but they either burned up or didnt really make it turn so I just connected the motor to test. any suggestions?

What mosfets are you using ? ..... you need low voltage high current mosfets, like IRF4905 or similars (anyway, at least 10 times the current rated for the motor current in free-running, cause under load the current of the motor increase a lot) ..... NOT high voltage mosfets, that are usually rated for low currents .....

Im currently using IRF510's on this build. I figured that they were the right choice but im not entirely sure.

IRF510 ..... RdsON 0,6 ohm, current 4A ..... not the better one, but i think it had to resist, at least if your motor don't need to make a lot of efforts for turn ,,,,, BTW, what motor are you using, normal DC small motor with a demoltiplication gearbox ? ..... or something that requires high currents ?

Anyway, IRF510 still need to be heatsinked, imho, cause with 600 milliohm of RdsON, it will produce a lot of heat (600mW each A, may not look so much, but are 600mw/SECOND, after all) ..... and a DC motor can require much more current under effort than the one rated for free-running (i have small DC motors that are rated 500mA in free running, that are also rated 4,5A in max torque cycle and 14A in stopped rotor condition, ofcourse this burn the motor in minutes, if you power up it with blocked rotor, but the currents are these ones).

A more powerful mosfet will be much better, like as example these ones (and remember that less is the RdsON, less is the power turned in heat from the mosfet itself in ON condition):

IRF1010: 60V, 84A max, 12 milliohm RdsON

IRF1104: 40V, 100A max, 9 milliohm RdsON

IRF2805: 55V, 75A max, 4.7 milliohm RdsON

IRF1503: 30V, 75A max, 3.3 ohm RdsON

and so on ..... still need a heatsink, imho, but these ones have also enough current for work without blow up in seconds also without a heatsink (also if probably they will become hot).

Also, if you can access an oscilloscope, try to check the waveform that drive the mosfet ..... more the fronts (up and down part of the waveform) are vertical and "quick", and with no spikes, and better it is ..... remember that a PWM circuit dissipate more energy in heat in the rising and falling times of the waveform, than in the ON state, so, more they are quick and clean, and better it is.

Alright after a little bit of work and some problems with balancing I present to you the led windmill. Thanks to everyone who helped me out with this.

http://www.youtube.com/watch?v=PHFkt8MwWME

I like it, a very unique look to it! Great job! Hopefully soon I'll start working on one myself.

Congratz hardwire! very cool

I'm using PS2 controller motors for my project, and here's the question: what's the voltage? I think it its 5v, but I wanna make sure

thanks

That is probably one of the coolest things I have ever seen a DIY'er make, you can definitely expect kipkay to copy this and call it a "led wood hack" or something.
Awesome job man!

Beautiful

With those clumsy two left meathooks of his? Not in a 1000 years....

Hi Folks.
First time here and I want to say how impressed I am with the orbs. They look fantastic.
Whilst reading the construction notes I could see similarities to issues I have with some of my projects (I do animatronics)

1. Communtators to transfer power. This is always an issue because you need something that will spin, as well as carry the power. I have found the 4 connector 2.5mm (and 3.5mm) video plugs and sockets great. You can use silicone grease for lubrication.
(Link here PRO SIGNAL|PSG01491|PLUG, 2.5MM JACK, 4POLE | Farnell United Kingdom PRO SIGNAL|MJ-069|SOCKET, 2.5MM JACK, 4POLE | Farnell United Kingdom )
That will give you 4 conductors. If you need more then put one at each end and use the motor with either gearing or a simple pulley and belt arrangement like in old cassette units, then you can have 8 links.

2. Easy solderable materials. I find that paper clips - straightened and then soldered gove a very strong result. Much stronger than standard component leads, plus they are very cheap. You can get a range of paper clip sizes and hence different thickness of wire.

Often I find that I need to control multiple LED's from a couple of wires. A 74HC154 is great because it can give you 4 to 16 lines to control the LED's (the 74HC138 is a 3 to 8, and the 74HC139 is a 2 to 4 decoder). As it has a Enable line on it you can use that for PWM and select the LED for lighting with the others Inputs. If you want to write some specialsed functions then use something like a PicAXE (which you can program in Basic) to give additional intelligence on the inner rings. You can work out your own communications but the PicAxe can handle serial, pulse length, IR, and A/D which gives you a lot of solutions.

Anyway - I'll keep looking around the site.
Take care.
Dave a.k.a. Marcwolf

Wow, that seems like it will solve many problems that I have ran into myself. I can't wait to try the video plug and socket technique. Thanks for the great tips!