I'll not be drawn into an argument over it, I was merely stating something that a less experienced reader may not have appreciated... and for them to then build it at face value and wonder why it doesn't perhaps work as it was intended. Even you yourself acknowledge ,now it's been pointed out, that perhaps it won't perform as well as first thought.
And really, if you think I just sit on the sidelines and "heckle", then you have been very very selective in your reading of the threads and replies of mine over the months and years.
I am capable of designing a MOSFET driver. On balance, I chose to omit it.
I also looked at putting the transformer in the drain circuit...
I have also ignored the fact that TTL dislikes having outputs connected together.
Now you have an opportunity to submit an alternate circuit.
w
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Come on! I am trying to make a power supply which will put out a 35-50 Khz 1v AC sine wave. There are to be NO TRANSISTORS OR IC's!!!!!!
I wonder if it might be possible to use a 12v relay to buzz an automotive coil, which will run a Tesla circuit. This Tesla circuit would have a capacitor, automotive spark-plug, and that would make HF AC around 1-3 Mhz. That HF/HV AC would be stepped down with a small Tesla coil to 12-14v HF AC.
I don't know if that can work. But any ideas on how to make this would a spark gap?
I appreciate any help, thanks.
I wonder if it might be possible to use a 12v relay to buzz an automotive coil, which will run a Tesla circuit. This Tesla circuit would have a capacitor, automotive spark-plug, and that would make HF AC around 1-3 Mhz. That HF/HV AC would be stepped down with a small Tesla coil to 12-14v HF AC.
I don't know if that can work. But any ideas on how to make this would a spark gap?
I appreciate any help, thanks.
You have lost me on what you are trying to do.
35 to 50 khz at 1 volt amplitude, sinusoidal, using no transistors or IC's. You need active devices !
A 12 volt relay ? that will switch at most a few 10's of hz if connected to "interupt" it's own coil supply.
Wouldn't like to say what the output of an automotive coil would look like at that... it would probably wipe out radio and tv for quite some distance.
Maybe I don't understand what you are trying to do.
I am trying to make an audio magnetic amplifier. I am going off of instructions from this website:
Homemade Magnetic Audio Amplifier.
plus this video: YouTube - Homemade magnetic amplifiers made from common materials.
For the amp part I am going to try using the cores from a bunch of ATX power supplies. They have good 1:1 saturation reactors in them.
Now the prickly part nobody has a real answer for: it needs a 35+ Khz AC supply. You can use a triode tube according to this old paper:
http://www.aes.org/aeshc/pdf/how.the.aes.began/vincent_magnetic-audio-fundamentals.pdf
But it doesn't have any specifics as to build the thing! And Nobody I talk to in town has the foggiest notion what I am talking about. Google has been next to useless.
My aim is to build a stereo mag-amp using WWII era technology. To run headphones or small speakers. Why? Because its neat.
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Never mind Mooly, it's pretty obvious that the OP is not to be taken too seriously, which is why the circuit I posted is not to be taken too seriously.
I'm sorry if I was a bit short in my remarks to you, I hope you will forgive me...
w
High frequency alternators were used in the early days of radio, but they produced considerably higher voltages, and anyway, nobody would construct one nowadays.
I'm sorry if I was a bit short in my remarks to you, I hope you will forgive me...
w
High frequency alternators were used in the early days of radio, but they produced considerably higher voltages, and anyway, nobody would construct one nowadays.
You could use the Poulsen principle, but with a lower frequency tuned circuit.
The "active element" doesnt need to be a real arc, you could use some kind of low pressure spark-gap, like a surge arrester or similar. Some have breakdown voltage under 80V and have a substantial negative resistance.
A Working Poulsen Arc Oscillator
There are numerous straightforward ways in which a person with some technical education can make a considerable nuisance of themselves to those in their immediate vicinity, and even those at some remove.
Generally as people educate themselves they develop an awareness of how their activities can impact on others and this is usually accompanied by an element of self-restraint.
For this reason most radio amateurs, for example, are quick to give a few hints to an individual who is obviously striving to expand their technical knowledge, but are less quick to hand over details of how to construct a potentially antisocial device on the basis that owning one would be 'neat'.
w
CivicProtection
OK... I can understand the curiosity value of something like this so, and I think I mentioned this earlier (haven't read through it all again), but why not build it all up apart from the 35khz source and then in the first instance use an old amp or a power IC and variable sinewave oscillator and make sure the thing actually works as intended.
This way you have total control over the HF signal with regards to frequency/amplitude and can determine what works best for your components and magnetics etc.
Then look at ways of obtaining a signal you know works. Although I have zero experience of this circuit (never even heard of it before this) I bet getting the HF at some optimum value is the key to it's success.
OK... I can understand the curiosity value of something like this so, and I think I mentioned this earlier (haven't read through it all again), but why not build it all up apart from the 35khz source and then in the first instance use an old amp or a power IC and variable sinewave oscillator and make sure the thing actually works as intended.
This way you have total control over the HF signal with regards to frequency/amplitude and can determine what works best for your components and magnetics etc.
Then look at ways of obtaining a signal you know works. Although I have zero experience of this circuit (never even heard of it before this) I bet getting the HF at some optimum value is the key to it's success.
IMHO, a small gas-filled tube exciting a 35KHz resonant circuit is pretty harmless (to audio devices anyway) compared to mobile phones.
What can you do when 95% of the population is "antisocial".
Are you going to issue ASBOs to PLCs users?
Another approach:
Take a multipole stepper motor and drive it as an alternator from a suitable motor.
If the motor has a 1.8 degree step angle (200 steps/rev) then for 35Khz you need ~10,000 RPM (Easy with a smallish DC machine).
You could even use saturatable reactors to build a frequency doubler....
Regards, Dan.
Take a multipole stepper motor and drive it as an alternator from a suitable motor.
If the motor has a 1.8 degree step angle (200 steps/rev) then for 35Khz you need ~10,000 RPM (Easy with a smallish DC machine).
You could even use saturatable reactors to build a frequency doubler....
Regards, Dan.
CivicProtection, I'm not trying to discourage you or disspate some of your interest in magnetic amplifiers, but they were around in the age of vibrator switching power supplies. The reason practical circuits using these techniques are so hard to find these days is that newer technologies made them silly in a hurry long ago. Anyone that's ever used a vibrator switch, except maybe manufacturers of them, was happy to throw them out. Direct electromagnetic generation is probably the cleanest angle. A carefully designed multi-pole generator can supply highly sinusoidal output at high frequencies without very high shaft RPM, lower being quieter. You could look into the axial flux PM designs that are being built for home brew wind power. The examples on the net can be very primitive, but you might understand what you need to do for optimization in your application. Hand buidling high performance motors and generators is a serious project in itself, but it might be hard to obtain anything off the shelf that has quite sinusoidal output. The drive side for the genemotor could be from any over-specified AC induction motor so that it ran essentially synchronous. Large amounts of flyweight might be inherent and some damping in the coupled shaft can help keep drive harmonics out of the driven shaft. What a crazy project.
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My reason for building such an amplifier is not just because it is 'neat', I would like to see if it could be done. I've built other things, and this is more exotic.
Hey I thought of that, but I could only find sparse material on the mag-amp, and nothing on making HF with the same. Any ideas?
My reason for building such an amplifier is not just because it is 'neat'. I find the technology to be interesting, and I don't want to bore you going on and on about why I think it is 'cool'.
Also I would like to see if it could be done by me. I've built other things, and this is more exotic.
Dimming a bulb with saturatable reactors is possible, next is to amplify sound.
Also I would like to see if it could be done by me. I've built other things, and this is more exotic.
Dimming a bulb with saturatable reactors is possible, next is to amplify sound.
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IIRC there was an article in one of the UK hobby electronics mags (Elector, E&WW, someone like that) about building a 70Khz transmitter using this sort of thing during the anniversary of Marconi making his first Transatlantic contact.
Basically bias the core to near saturation in one direction with DC, inject the exciter power and as the core runs into and out of saturation you get harmonic generation.
It is not much used these days, active parts providing a much more efficient way to do this.
Regards, Dan.
Basically bias the core to near saturation in one direction with DC, inject the exciter power and as the core runs into and out of saturation you get harmonic generation.
It is not much used these days, active parts providing a much more efficient way to do this.
Regards, Dan.
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