Using a similar circuit to the LF block converter, I`ve made a Schumann Resonance Converter that moves the near-DC signals up to around 2 kHz for an ordinary soundcard. Here`s the maiden run plot: It seems to work! The fuzzy lines below 30 Hz are due to the Schumann Resonance. The image is from Spectrum Lab with an offset of 2. 048 kHz (the L. O. f
Click here to download the full size of the above Circuit.
requency). The 60 Hz is reduced by an unusual bridged-T notch filter that uses a little audio transformer as the inductor. I discovered that the inductance of such a transformer can be varied quite a bit with a very tiny current (or even a weak magnet). Only 100 uA of DC current will tune the filter many 10`s of Hz! Here`s a snapshot of the schematic so far: Circuit Starting on the left, the antenna should be a fairly long vertical mounted high in the air, away from trees. The lead-in cable will have significant capacitance, perhaps as much as 1000 pF, and that`s fine. (In fact, you might want to add a shunt capacitor if the hum is too big for the FET follower. If that`s the case, you might also try increasing the 220 pF capacitor, to, say, 470 pF, but that`s starting to eat into the gain at the higher Schumann resonance frequencies. ) The first 62 megohm bleeds charge off the antenna and the neon bulb or other gas discharge device limits the voltage. Those components are on my RF connector, not in the photo. The. 01 uF helps to isolate the JFET from the voltage and it should have a high breakdown voltage, just in case. The second pair of 62 megohm resistors bias the JFET gate to V/2, to give the source plenty of room to swing, since there`s likely to be a big AC hum signal. Those big resistors could be comprised of 3, 22 megohms in series. The 10 megohm is in the signal path, but its noise is well below the atmospheric...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
characters left: