Crystal oscillator and amplifier purchase

AI Thread Summary
The discussion revolves around the decision to purchase a crystal oscillator and amplifier for a project focused on wireless power transfer, aiming for 30-40 volts peak to peak at frequencies above 1 MHz. The TL08 series op-amps are considered, although concerns are raised about their gain at 1 MHz. The user plans to experiment with different output impedances and transmitter designs, starting with a 2-inch power transfer distance. The conversation highlights the importance of RF spectrum regulations and safe experimentation methods, including various coupling techniques for effective power transfer. Overall, the focus is on achieving efficient wireless power transfer while navigating technical and regulatory challenges.
TeeBeeBee
Messages
5
Reaction score
0
in my previous thread i was trying to build a sine oscillator and an amplifier. decided to give up on the idea and purchase. any chips out there that can give me 30-40volts peak to peak. the frequency is not an issue as long as it is above 1 MHz. i guess i can use any crystal oscillator as long as the amplifier can give me 30V. TL08 series seem like a good option.
 
Engineering news on Phys.org
What output impedance will your circuit be driving?
Will it drive 50 ohm coaxial cable or maybe 400 ohm parallel line?
 
im experimenting with wireless power transfer so the circuit will be connected to a transmitter coil. the impedance is not set yet. i will be experimenting, changing the transmitter and the receiver once i get the power supply. thank you
 
TeeBeeBee said:
im experimenting with wireless power transfer so the circuit will be connected to a transmitter coil.
Most experimentation is now done using numerical simulation. With the exception of ISM allocations, the RF spectrum is allocated to important services that must not be interrupted. Your frequency and power levels will be critical to the attention you will receive from the authorities.
Can you please give more details of your experiment. Over what range do you expect to transfer power?
 
  • Like
Likes davenn and berkeman
i am starting with a small distance of 2 inches and hope to improve it with tests. Yes i will be careful with RF spectrum. Thanks
 
Hint,
To get power transferred, it can be electrostatic coupling, a traveling electro-magnetic wave, or magnetic coupling. An E-M wave needs to be focused which means extraordinarily huge antennas or extraordinarily high frequencies. Very bad and somewhat dangerous to fool with (i.e. making a microwave oven run with the door open dangerous).
Look at any Tesla coil demonstration and you can see the effects of high voltage coupling.
The method that works really good over short distances (and I think I posted a circuit on here) is to use a resonate Royer converter to excite an LC tank up to high currents. You need considerable currents in the inductor to get any significant power transfer. i.e. amp per 20-50 mw at 1 inch.
The current "revolution" in power transfer uses flat transformer halves coupling through a short distance. Again, one half has to maintain a fairly high
current in the primary to get anything useful from the secondary.
PS - any jelly-bean op amp, like a TL08x, will not have useful gain at 1MHz. There are plenty of oscillator circuits out there, but they require some skill with transistors or logic used in an analog fashion.
 
  • Like
Likes davenn
Thread 'Weird near-field phenomenon I get in my EM simulation'
I recently made a basic simulation of wire antennas and I am not sure if the near field in my simulation is modeled correctly. One of the things that worry me is the fact that sometimes I see in my simulation "movements" in the near field that seems to be faster than the speed of wave propagation I defined (the speed of light in the simulation). Specifically I see "nodes" of low amplitude in the E field that are quickly "emitted" from the antenna and then slow down as they approach the far...
Hello dear reader, a brief introduction: Some 4 years ago someone started developing health related issues, apparently due to exposure to RF & ELF related frequencies and/or fields (Magnetic). This is currently becoming known as EHS. (Electromagnetic hypersensitivity is a claimed sensitivity to electromagnetic fields, to which adverse symptoms are attributed.) She experiences a deep burning sensation throughout her entire body, leaving her in pain and exhausted after a pulse has occurred...
Back
Top