Jason:

Thank you for the heads-up on finding these fairly inexpensive battery operated function generators specifically to drive the three phase oscillators. I sure am looking forward to your good work on verification of the usefulness of these function generators. Only thing is, like you say it's only good for 500k hz? Maybe a problem if we needed higher harmonics.

Please let us know your progress. If they work well, I will be getting 3 myself too!

Regards
chrisC

Jason:

Thanks again. can you vary the duty cycle on these?

chrisC

ps .. i cant download the vid from the link or other vid downloaders .. it keeps erroring .. may be a prob on my end.

devilzangel
..

No devilzangel, your correct, theres an issue with google videos, I just tried another d/ler as well.
That d/l link used to work, somethings changed.:- http://javimoya.com/blog/youtube_en.php

I just sent google video an email, telling them of the problem with there videos, hopefully will get an answer, will let you guys know.

@Otto, appreciate your guidance, thank you.

Dom

Hello all,

sorry I was a few days off line.

I saw the last video. A few comments:

1. there are 2 frequencies used and everything was OK. Then the 3. frequency added and nothing was OK!!!

When you use 3 frequencies, when you see that the 3rd frequency "disturbs" the other 2 frequencies then you MUST surch for better frequencies. The first 2 frequencies are NOT GOOD. You have to find a better frequency mix for your first 2 frequencies and then add the 3rd.

When all 3 frequencies are OK then you can swith off 1 frequency and the bulb shines NOT so bright as with all 3 of them. Then swith off 2 frequencies and the bulb is maybe only glowing.

In this case you know that all your 3 frequencies adds a littl power to the bulb. This is then the frequency mix you need.

This is then what I call a harmonic work off all 3 frequencies.

Otto

This is what I was thinking as well Otto...I agree. It does seem odd that the 3 frequencies would diminish the output, if adjusted properly.

Do you agree that the 3 frequencies should be harmonically related, and that the frequencies are fundamental, 1st harmonic, 2nd harmonic?

If so, I don't understand why no one is using the harmonic divider I designed, and then one only has to input one frequency. This will allow you to just sweep slowly from your chosen starting frequency, then adjust upwards for peak output power? 


Regards,
Darren

@Jason,

Earl is correct: remove the 1 nF condenser on Mosfet's Gate! It will only decrease the pulse rise-time in our case!   If I were you I'll remove the resistor either as it does not need except perhaps for safety rule.

Roberto

@ZPE,

If it may be of help to know  I'm currently almost finished the designing a Sync/Async triple oscillator programmable  (:3 - :9999)  just with DIP switches. The rationale is to use the Async mode to discover the 3 sweet freq and then switch to sync mode...with attention as I've already seen much more output when synched.  I'll post soon the complete design.

The unit is divided into 3 Subassembly:

1 - Assembly has a single little board containing the Master Oscillator (Xtal) and the 3 LSI CD4059 prog counter in serial connection. DIP Switches provide for: BCD freq progr., Mode progr, Load of setting, Asyn/Synch operation.

2 - Assembly are actually 3 very small board just to accomodate each the Mosfet driver and power Mosfet and his heathsink. The little board is designed to be set near the external Mobius ring.

3 - Assembly does contain only the 2 Mobius ring.

Roberto

Another chip that may be of use is a binary rate mulitplier or BRM, 7497 or cd4089 although ive not gone that way yet myself so have no design.

Peter

Hello All,

I'm finally back from my weekend trip and thought I would take the time to draw up the the circuit diagram for my control circuit.

It uses the mic4427 MOSFET drivers for the IRF840 MOSFETs. For those of you wondering where to order them, they can be purchased inexpensively from this website here:

http://www.arrow.com/

Search for mic4427BN. That is the correct chip.

I am currently modifying my control circuit to output extremely small duty cycle square waves (500 ns pulse width) to conserve input power. My firm view is that we only want to put in enough current to load the coil inductance and no more. Any extra input will simply be wasted. The attached circuit diagram does not include the ICs I will be using for the pulse width control but I will be using the 74HC423N chip. It is a Dual retriggerable monostable multivibrator which, using a resistor and capacitor allows you to vary the output pulse width from a minimum of 75ns and up. The mic4427NB drivers need a minimum 500ns pulse width to turn on and off properly.

As soon as I have finished the modifications to the control circuit, I will post an updated circuit diagram.

The board I have currently runs on a single 9V battery and the input frequencies are controlled by three separate battery-powered function generators, which I bought from here:

http://www.electronickits.com/kit/complete/meas/fg500k.htm

They have a range of 1Hz to 1MHz. Above, 500k, the square wave output really breaks down but since the FET drivers are comparator driven, it won't affect the switching of the MOSFETs.

That should be all you need to make this circuit. If you want to use 555 timers, make sure that you put some capacitors in parallel with the power supply inputs to the timer chips because the FET drivers draw a lot of power when they are running. If you have any problems, PM me and I'll see what I can do to help you.

God Bless,
Jason O

Thanks Jason, I'll get on it tonight. Hope I have the caps and resisters, prolly have to get a couple rat shack grab bags of resisters, I think I have the caps.

Rich