How do i do high voltage frequency?

Click For Summary

Discussion Overview

The discussion centers around generating high voltage square wave signals in the frequency range of 100 to 300 kHz, with a focus on the use of a 555 timer and the necessary amplification methods to achieve the desired voltage and current levels. Participants explore various components and safety considerations related to high voltage and frequency applications.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant seeks recommendations for generating high voltage square waves at specific frequencies using a 555 timer.
  • Another suggests using power MOSFETs to amplify the signal, emphasizing the need for components rated for the required power transfer.
  • Concerns are raised about the suitability of 600 watt MOSFETs from audio amplifiers for high frequency applications, with advice to check their datasheets.
  • A participant proposes that switching MOSFETs may be more appropriate for generating square wave signals compared to linear amplifying transistors.
  • Safety concerns are highlighted regarding working with high voltages, particularly for those new to electronics, recommending lower voltage ranges for beginners.
  • Discussion includes potential hazards associated with high frequency signals, including the risk of electric shock and unintended heating effects on nearby objects.
  • Clarifications are made regarding the frequency ranges and associated risks, with one participant correcting a misunderstanding about the frequency of concern.
  • A participant shares a personal anecdote related to high power transmission and the dangers involved.
  • Another participant expresses gratitude for the information and decides to avoid high power projects for the time being.

Areas of Agreement / Disagreement

Participants express a mix of technical suggestions and safety concerns, with no consensus on the best approach to achieve the desired high voltage frequency generation. Safety warnings regarding high voltage work are generally acknowledged, but opinions on component selection and design approaches vary.

Contextual Notes

Participants mention the importance of checking specifications for components and the potential risks associated with high voltage and frequency applications, but do not resolve the technical details or safety guidelines discussed.

Who May Find This Useful

This discussion may be useful for electronics enthusiasts, particularly those interested in high voltage applications, signal generation, and safety considerations in experimental setups.

flobro
Messages
4
Reaction score
0
how do i do high voltage frequency?

i have been working with a 555 timer but i want to do a square wave 100 to 300 khz at up to 100 volts and 3-6 amps so i need something much larger any recomendations? thanks
 
Engineering news on Phys.org
That is a lot of power. I think you can use the 555 timer as your small signal generator. You need to amplify this signal. Just putting it through a transformer will not be enough because the energy has to come from somewhere. You will need some power MOSFETs probably to amplify the signal to a high voltage, and these MOSFETS need to be rated for the amount of power you're trying to transfer (600 Watts). From this stage, depending on what voltage you amplified the original signal to, you can then pass the signal through a transformer to step up the voltage to what you need. The key is you need to amplify the original signal with an amplifier that can drive the power you need. Also you need to make sure there is minimal attenuation on your amplifier stages at the frequencies youre generating. I hope this sets you in the right direction, but there are some more experienced people here who can help you better.
 
thanks TheAnalogKid83 now i have something to work with
 
does anyone know if 600 watt mosfet's from an audio amplifier will work?
 
possibly, although those are in a design where the signals amplified are much lower frequencies than the frequencies youre talking about. Check the datasheet for their part number and see what frequencies they operate at.
 
also, I'm not the best at electronics, but if youre doing a square wave, a switching mosfet might be what youre looking for (i am assuming switching mosfets are on/off for square wave type waveforms instead of operating in the linear region of a transistor). A switching transistor is a lot easier to design than an amplifying transistor in my opinion, and this may be all that you need.
 
flobro said:
i have been working with a 555 timer but i want to do a square wave 100 to 300 khz at up to 100 volts and 3-6 amps so i need something much larger any recomendations? thanks

Why do you want to go to that high of a voltage? It's quite dangerous to be working with voltages over about 42V (Underwriter's Labs limit for low voltages), especially if you are just now learning about electronics. I'd strongly suggest that you stick with voltages more in the 30-40V range for now.
 
Yes. And these high frequencies can easily couple into objects; like your ring (glowing red hot almost instantaneously) and could boil you bodily fluids.

Berkeman, correct me if I'm wrong.
 
dlgoff said:
Yes. And these high frequencies can easily couple into objects; like your ring (glowing red hot almost instantaneously) and could boil you bodily fluids.

Berkeman, correct me if I'm wrong.

Not really at 300kHz. That would be more like microwave oven frequencies in the ISM band around 2.4GHz. The main risk of <1MHz high voltage AC waveforms (and the HV DC power supplies for powering the amplifier circuits) is from electric shock. Once you get into the MHz region, you add the issue that you are violating FCC rules about putting out harmful interfence with broadcast radio and other bands. You will get a very serious knock on your door if you do that.
 
  • #10
My bad. I saw MHz when the OP said kHz.

The ring thing came from a story a old ham told me when I was a kid. He was matching his transmitter to an antenna by taping a tuning coil. He said that he accidentally aligned his finger with the coil and the ring almost burned his finger off.
 
  • #11
dlgoff said:
My bad. I saw MHz when the OP said kHz.

The ring thing came from a story a old ham told me when I was a kid. He was matching his transmitter to an antenna by taping a tuning coil. He said that he accidentally aligned his finger with the coil and the ring almost burned his finger off.

Oh, baby! Yeah, when you're talking kW of transmit power, you've got to be pretty careful. Yeowtch!
 
  • #12
thanks for the concern and the good information, and i think i will leave the high power stuff for the experts, i found what i was looking for on ebay. this is a great forum though and i will be back
 

Similar threads

How to Safely Generate High Voltage for Capacitor Testing?
  • · Replies 49 ·
2
Replies
49
Views
5K
How Does Resonance Frequency Affect MEMS Accelerometer Performance?
  • · Replies 1 ·
Replies
1
Views
2K
How to figure the voltage drop at different points along a circuit?
  • · Replies 38 ·
2
Replies
38
Views
7K
Faraday disc voltage increase
  • · Replies 3 ·
Replies
3
Views
2K
Can Human Bodies Tolerate High Frequency Electrocution at 100 KHz?
  • · Replies 2 ·
Replies
2
Views
2K
Resistance of wet sponge with voltage
  • · Replies 10 ·
Replies
10
Views
2K
Choosing a pulse capacitor, ESR vs reactance at frequency
  • · Replies 5 ·
Replies
5
Views
2K
Can Resonant Frequency Disassociate Water Molecules?
  • · Replies 12 ·
Replies
12
Views
4K
I tried building an induction coil
  • · Replies 34 ·
2
Replies
34
Views
3K
AC to DC voltage doubler not working
  • · Replies 7 ·
Replies
7
Views
4K