Hero999

He mentioned antennae which implies he wants electromagnetic radiation. If he wants sound that would work but only to 10Hz with a decent subwoofer, not 0Hz.

All good ideas John but be warned about the ones which pass DC through the water which can cause corrosion problems due to electrolytic action.

It won't work because to radiate a significant amount of power the antenna needs to be a significant length compared to the wavelength you want to transmit with 1/4 of a wavelength being optimal. The wavelength of an electromagnetic wave can be calculated using the following formula: l = c/f l = wavelength c = speed of light in a vacuum = 299.8*106m/s which is nearly 300,000km per second. f = frequency in your case the maximum frequency is 1000Hz. l = 299.8*103/1000 = 299.8*103m = 299.8km So the ideal 1/4 antenna lengh is 299.8km/4 = 74.95km long - too big for your back garden even if you sacrificed efficiency and cut the length to 1/16 of a wavelength. At 10 Hz the ideal antenna length will be ten times that and at 0Hz you'll get a divide by zero error which indicates it's impossible to build an infinitely large antenna capable of transmitting DC power through empty space. I suggest you look into RF therory a bit more. What molecules are you hoping to vibrate at such low frequencies? You need much higher frequencies for that, in the order of 100THz and no molecular resonances occur below the micowave band. Is suggest you do more research into chemistry and molecular physics.

You haven't provided enough information. Why do you want to do this? You need to be aware that you can't directly transmit 0Hz through the air and transmitting frequencies below 100kHz or so is difficult. You can however transmit a much higher frequency i.e. 27MHz and superimpose the lower frequency signal on it; this is known as modulation and is used for TV and radio broadcasts. You should also know that it's not possible to efficiently transmit power from one place to another using RF so forget about transmitting the 8HP from your generator to a remote location via RF.

I'm glad you like it and hope you stary around and contribute to the community.

Read the license agreement to find out whether it's legal to redistribute it or not. If it doesn't have a license agreement assume you can't post it here unless you've sought permission from the copyright holder. You can upload your own avatar be clicking on the profile information section in the profile settings. Here's a link which should take you there http://www.electronics-lab.com/forum/index.php?action=profile;u=62678;sa=forumProfile This link will only work for you when you're logged in to the account you used to make your previous post.

Use a pot and ball cock to give a varible voltage depending on the depth. Use some comparators such as the LM339 to light the LEDs depending on the input voltage.

Your question makes no sense and a poll is equally pointless. Be more specific: what do you want to know? And turn off the capslock key.

You won't get 91.1k because it's not a standard value and at 10% tolerance it's impossible.

If it's too big then upload it to a file hosting site.

Yes and no doubt he'll ask the same question again and again.

It also has a variable oscillator and mixer to produce a fixed intermediate frequency so a high Q tuning circuit can be used to give excellant selecxtivity.

You should use a ferrite rod or loop aerial if you don't want to rely on an external earth connection.

Please post in English.

By using a formula which can be found using Google. http://www.google.co.uk/search?hl=en&client=opera&hs=4eV&rls=en&channel=suggest&q=inductance+calculation&aq=f&aqi=g7g-m3&aql=&oq=

I've never done it before so wouldn't be able to answer that question. What's the resistance and inductance of the coil? You should ensure the impedance of the capacitors and wiring is significantly less than that of the coil.

I'd be very careful if I were you, playing with the braking system is not a good idea: if your project goes wrong it could cause an accident. There are practical problems too: the breaks will wear down very quickly and fuel consumption sky-rocket. You'd be better off cutting power to the engine but even that can be dangerous if it goes wrong. The project is theoretically very simple, count the number of revolutionsover a fixed period of time using an encoder and apply the break or cut the engine power if it exceeds a certain limit. A single microcontroller could be used or a counter IC with some logic gates. It's just a bad idea for safety reasons.

You haven't provided enough information. I made a battery charger to charge two 14Ah sealed lead acid batteries connected in series in my shed using an LM317 which just served to limit the voltage from the panels. The charge current was well within the specification of the battery.

Why build a very inefficient class A amplifier when you can make an efficient class AB ampflieir which sounds as good? The only real use for a depletion power MOSFET is a normally open solid state relay.

Sorry no one's going to give you a project, the whole point is you design it yourself. If you make an effort and propose a design we might be able to point out where you've gone wrong and suggest improvements.

It sounds like you're not limiting the duty cycle so the inductor is saturating. Why not simply replace the light bulb with one designed to run on 12V? Using an SMPS to power something which can easily be changed to the correct voltage is bad design.

Just make the connections as short and as thick as possible. What are you using for back-EMF protection? Electrolytic capacitors don't like being charged in the reverse direction.

You really need to provide more information. It depends on the capacitance, voltage and rate of discharge.

Not if the circuit is assembled correctly. C1 AC couples the feedback from the inductor to the transistor. I'd be surprised if this circuit works at all with R1 at 1M. The proper way is to bias the transistor with a potential divider.

Did you click on either of the links in my previous post? One of the reasons you probably can't find any circuits is because there was no Internet when they were created. There are many ways to do this. One I can think of is to use two oscillators in the transmitter, each with slightly different frequencies and have filters in the receiver to decode the output. Different crystals can be both used as filters as well as oscillators.