Author Topic: The VIC with resonant cavity project by Steve..  (Read 81432 times)

0 Members and 3 Guests are viewing this topic.

Online Login to see usernames

  • Administrator
  • Hero member
  • ****
  • Posts: 4440
    • water structure and science
Re: The VIC with resonant cavity project by Steve..
« Reply #200 on: January 27, 2016, 21:57:39 pm »
Thanks guys!

How about this diode?   STTH15S12
Its used for boosting circuits....
Its a bit quicker in recovery Trr and also morr volts and amps....

Cheers

Offline Login to see usernames

  • Member
  • **
  • Posts: 184
Re: The VIC with resonant cavity project by Steve..
« Reply #201 on: January 27, 2016, 22:03:42 pm »
jumping in here. I tried the stth.  it got hot and smoked. the microwave diodes run cool, fwiw

I recently put a old car ignition coil on each side of my array and saw a nice improvement running at 3 ma.

kb

Offline Login to see usernames

  • Global Moderator
  • Hero member
  • ****
  • Posts: 3607
Re: The VIC with resonant cavity project by Steve..
« Reply #202 on: January 28, 2016, 01:53:28 am »
does anyone know how much reverse current is needed for a diode reach the piv to break?

on tvs the current can be very high... but i know some diodes are avalanch rated meaning if i understood well that if we apply a voltage greater than the reverse piv than there  is a current flow but also high power dissipation on the diode because the high voltage times reversed amp...

http://www.datasheetspdf.com/PDF/1N1198/532201/1

i work here with some tvs called 1,5ke400c this kind of is A POWER zenner and ultra fast too...basically as the voltage aproach the zenner voltage the current reach a point where above it it increase exponentialy... its used to protect my switching devices... unfortunatelty this is the most powerfull i could find here in brazil... there are better options outside here...   

i use them in series and parallel to increase the power it can handle here..

Offline Login to see usernames

  • Member
  • **
  • Posts: 176
Re: The VIC with resonant cavity project by Steve..
« Reply #203 on: January 28, 2016, 06:35:41 am »

you can look at data sheets of any diode
Im using 1.5KE18A
what are you protecting?

http://www.littelfuse.com/products/tvs-diodes/leaded/1_5ke.aspx






Online Login to see usernames

  • Administrator
  • Hero member
  • ****
  • Posts: 4440
    • water structure and science
Re: The VIC with resonant cavity project by Steve.. some thoughts about harmonic
« Reply #204 on: February 01, 2016, 15:58:50 pm »
Application of nonsinusoidal excitation voltages to transformers increase the iron lesses in the magnetic core of the transformer in much the same way as in a motor. A more serious effect of harmonic loads served by transformers is due to an increase in winding eddy current losses. Eddy currents are circulating currents in the conductors induced by the sweeping action of the leakage magnetic field on the conductors. Eddy current concentrations are higher at the ends of the transformer windings due to the crowding effect of the leakage magnetic fields at the coil extremities. The eddy current losses increase as the square of the current in the conductor and the square of its frequency. The increase in transformer eddy current loss due to harmonics has a significant effect on the operating temperature of the transformer. Transformers that are required to supply power to nonlinear loads must be derated based on the percentages of harmonic components in the load current and the rated winding eddy current loss.

Online Login to see usernames

  • Administrator
  • Hero member
  • ****
  • Posts: 4440
    • water structure and science
Re: The VIC with resonant cavity project by Steve..
« Reply #205 on: February 23, 2016, 00:11:50 am »
Hi,

Here a scopeshot of what i see acros my primary of the VIC. I was able to remove some nasty spikes at the beginning of the pulses.
I think it looks nice. Ron advised to spend lots of time on the primary...so i did. I added 3x 220ohms resistors across the prim and a fast switching diode as well. Hope it is good enough.
Tomorrow i need to tune the chokes. Take some windings off till certain lenght?
Any tips?

Cheers

Offline Login to see usernames

  • Global Moderator
  • Hero member
  • ****
  • Posts: 3607
Re: The VIC with resonant cavity project by Steve..
« Reply #206 on: February 23, 2016, 00:33:43 am »
Beautiful waveforms Steve

i never get that positive spike on mine maybe because i dont use a diode across the coil...

this seem like the current is not falling to zero on the coil..

Online Login to see usernames

  • Administrator
  • Hero member
  • ****
  • Posts: 4440
    • water structure and science
Re: The VIC with resonant cavity project by Steve..
« Reply #207 on: February 23, 2016, 00:40:15 am »
Beautiful waveforms Steve

i never get that positive spike on mine maybe because i dont use a diode across the coil...

this seem like the current is not falling to zero on the coil..

Well, if i remove that diode from across the prim, the totall waveform goes bad..
As far as i understood, a squarewave creates the most harmonics.
So, the better square it looks, the better it must be....