Crystal oscillator and amplifier purchase

Click For Summary

Discussion Overview

The discussion revolves around the purchase of a crystal oscillator and amplifier suitable for a wireless power transfer experiment. Participants explore various components and their specifications, particularly focusing on achieving a peak-to-peak voltage of 30-40 volts at frequencies above 1 MHz.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • One participant expresses a desire to purchase chips capable of delivering 30-40 volts peak-to-peak, suggesting the TL08 series as a potential option.
  • Another participant inquires about the output impedance of the circuit, questioning whether it will drive a 50 ohm coaxial cable or a 400 ohm parallel line.
  • A participant mentions that their circuit will be connected to a transmitter coil for wireless power transfer, indicating that the impedance is not yet determined and will be adjusted during experimentation.
  • Further discussion highlights the importance of RF spectrum regulations and the need for careful consideration of frequency and power levels in wireless power transfer experiments.
  • One participant shares their initial goal of transferring power over a distance of 2 inches, expressing intent to improve this distance through testing.
  • Another participant provides insights on methods of power transfer, including electrostatic coupling, electromagnetic waves, and magnetic coupling, cautioning about the dangers associated with high voltage coupling.
  • Concerns are raised regarding the suitability of the TL08x op amp for high-frequency applications, suggesting that it may not provide useful gain at 1 MHz.

Areas of Agreement / Disagreement

Participants express various viewpoints on the components and methods for wireless power transfer, with no consensus reached on the best approach or specific components. The discussion remains unresolved regarding the optimal design and specifications for the circuit.

Contextual Notes

Participants mention the need for experimentation and adjustments in impedance and distance, indicating that the discussion is contingent on ongoing testing and exploration of different configurations.

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   Reactions: 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   Reactions: davenn

Similar threads

  • · Replies 12 ·
Replies
12
Views
3K
Replies
8
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 37 ·
2
Replies
37
Views
5K
  • · Replies 46 ·
2
Replies
46
Views
6K
  • · Replies 27 ·
Replies
27
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 41 ·
2
Replies
41
Views
8K
  • · Replies 28 ·
Replies
28
Views
6K
  • · Replies 28 ·
Replies
28
Views
3K