Welcome
Username or Email:

Password:


Missing Code




[ ]
[ ]
Online
  • Guests: 17
  • Members: 0
  • Newest Member: omjtest
  • Most ever online: 396
    Guests: 396, Members: 0 on 12 Jan : 12:51
Members Birthdays:
One birthday today, congrats!
GrantX (34)


Next birthdays
03/30 Adam Horden (39)
03/30 Mr.Warwickshire (23)
03/31 Swedish Coiler (41)
Contact
If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.


Special Thanks To:
  • Aaron Holmes
  • Aaron Wheeler
  • Adam Horden
  • Alan Scrimgeour
  • Andre
  • Andrew Haynes
  • Anonymous000
  • asabase
  • Austin Weil
  • barney
  • Barry
  • Bert Hickman
  • Bill Kukowski
  • Blitzorn
  • Brandon Paradelas
  • Bruce Bowling
  • BubeeMike
  • Byong Park
  • Cesiumsponge
  • Chris F.
  • Chris Hooper
  • Corey Worthington
  • Derek Woodroffe
  • Dalus
  • Dan Strother
  • Daniel Davis
  • Daniel Uhrenholt
  • datasheetarchive
  • Dave Billington
  • Dave Marshall
  • David F.
  • Dennis Rogers
  • drelectrix
  • Dr. John Gudenas
  • Dr. Spark
  • E.TexasTesla
  • eastvoltresearch
  • Eirik Taylor
  • Erik Dyakov
  • Erlend^SE
  • Finn Hammer
  • Firebug24k
  • GalliumMan
  • Gary Peterson
  • George Slade
  • GhostNull
  • Gordon Mcknight
  • Graham Armitage
  • Grant
  • GreySoul
  • Henry H
  • IamSmooth
  • In memory of Leo Powning
  • Jacob Cash
  • James Howells
  • James Pawson
  • Jeff Greenfield
  • Jeff Thomas
  • Jesse Frost
  • Jim Mitchell
  • jlr134
  • Joe Mastroianni
  • John Forcina
  • John Oberg
  • John Willcutt
  • Jon Newcomb
  • klugesmith
  • Leslie Wright
  • Lutz Hoffman
  • Mads Barnkob
  • Martin King
  • Mats Karlsson
  • Matt Gibson
  • Matthew Guidry
  • mbd
  • Michael D'Angelo
  • Mikkel
  • mileswaldron
  • mister_rf
  • Neil Foster
  • Nick de Smith
  • Nick Soroka
  • nicklenorp
  • Nik
  • Norman Stanley
  • Patrick Coleman
  • Paul Brodie
  • Paul Jordan
  • Paul Montgomery
  • Ped
  • Peter Krogen
  • Peter Terren
  • PhilGood
  • Richard Feldman
  • Robert Bush
  • Royce Bailey
  • Scott Fusare
  • Scott Newman
  • smiffy
  • Stella
  • Steven Busic
  • Steve Conner
  • Steve Jones
  • Steve Ward
  • Sulaiman
  • Thomas Coyle
  • Thomas A. Wallace
  • Thomas W
  • Timo
  • Torch
  • Ulf Jonsson
  • vasil
  • Vaxian
  • vladi mazzilli
  • wastehl
  • Weston
  • William Kim
  • William N.
  • William Stehl
  • Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Forums
4hv.org :: Forums :: Projects
« Previous topic | Next topic »   

Miniature wireless power demonstrator

Move Thread LAN_403
mister_rf
Tue Apr 24 2012, 11:29AM
mister_rf Registered Member #4465 Joined: Wed Apr 18 2012, 08:37AM
Location: Bucharest, Romania
Posts: 145
KrystaL wrote ...

Hello guys , i want to ask can we use 1.6MHz oscillator , and amplify its amplitude to that level , becoz these compionents are not easily available in my area
No, that's more complicated solution than the original version.
However, try to use other types of transistors. I have managed to test in circuit various MOSFET transistors. (Empirical tests only, not claim to scientific value. cheesey )

The initial setup:
• Vcc = 12V
• Rg = 100 ohms (R1, R2)
• Diode D1,D2 = STTH3R02 -ultrafast 200V/3A
• DiodeD3, D4 = SR810 schottky 100V/8A
• L = 1 turn/ 210 mm diameter/13 mm Copper tube
• capacitor C = 22nF/ FKP type 1000V

I have measured for each transistor:
•current consumption without external load = ' Io'
•the on load current = 'Is' ,(for a 50 mm clearance between transmitter and receiver coils).
•the maximum distance for light bulb filament still glowing => 'dmax'

And the results:
1. IRF520NPBF N-Ch 100V 9,7A 48W 0,20R TO220AB (• Turn-On Delay Time: 4.5ns • Turn-Off Delay Time: 32ns)
Io = 0.38A, Is = 0.78A, dmax= 490mm
2. IRF530PBF N-Ch 100V 14A 88W 0,16R TO220AB(• Turn-On Delay Time: 10ns • Turn-Off Delay Time: 23ns)
Io = 0.42A, Is = 0.85A, dmax= 470mm
3. IRF540NPBF N-Ch 100V 33A 130W 0,044R TO220A (• Turn-On Delay Time: 11ns• Turn-Off Delay Time: 39ns)
Io = 0.48A, Is = 0.95A, dmax= 470mm
4. IRF630PBF N-Ch 200V 9A 74W 0,4R TO220AB (• Turn-On Delay Time: 9.4ns• Turn-Off Delay Time: 39ns)
Io = 0.4A, Is = 0.85A, dmax= 470mm
5. IRF640NPB N-Ch 200V 18A 150W 0,15R TO220AB (• Turn-On Delay Time: 10ns • Turn-Off Delay Time: 23ns)
Io = 0.44A, Is = 0.9A, dmax= 460mm
6. IRF740PBF N-Ch 400V 10A 125W 0,55R TO220AB (• Turn-On Delay Time: 14ns • Turn-Off Delay Time: 50ns)
Io = 0.46A, Is = 0.92A, dmax= 450mm
7. IRF3808 N-Ch 75V 140A 330W 0,007R TO220AB
No results for the actual setup circuit…

• Next, the power supply voltage tests.
I have kept one pair of IRF520 on place, then start increasing the power supply voltage up to 30V. Maximum distance for the 12V/5W load (light bulb steady on condition) has increase up to 750mm, and the 'no load current' increase up to 0.8A. The only problem Rg=100 ohms went on fire!... cheesey By the other hand the minimum required voltage for the power supply: 7V-7.5V.

• The 'Rg' resistor test ('R1' and 'R2' in the actual schematic)
I have keep the original circuit configuration (IRF520, Vcc= 12V), and I have managed to increase 'Rg' value up to 720 ohms for a 'no load current' =0.23A. Finally all the IRF 520/530/540/630/640 and 740 transistors do the job using a 680 ohms (0.25W) standard resistor value.

• The diode test.
I have run some test for the diodes used to discharge the MOSFET gates, same setup circuit IRF520, Vcc=12V and Rg= 680 ohms.
The following diodes types were tested
- STTH3R02, those are running very cool, Io= 0.23A
- 1N4148. Not all the diodes I have tested can manage the situation OK, some are very hot, some were destroyed and 'Io' (the 'no load current') increase up to 0.35A
- MBRS1100T3G, running cool, 'Io' = 0.25A
- BA157, BA159 series, running OK, just a little warmer, 'Io'= 0.35A
- BYV27, running cool, 'Io' = 0.28A

And my final conclusion for these tests:
at 12V power supply we get perfect results using any of the transistors and diodes mentioned above. This allow to increase the 'Rg' resistors value and hence reducing power losses in resistors.
In any situation need to use always some very good capacitors, as the recommended FKS/FKP/MKS or MKP foil polyester series.
Back to top
THOMAS18
Tue Apr 24 2012, 01:06PM
THOMAS18 Registered Member #4267 Joined: Fri Dec 16 2011, 09:17AM
Location:
Posts: 16
mister_rf wrote ...

In order to power up a small DC fan you need to use a rectifier bridge.
The purpose of the rectifier section is to convert the incoming alternating current from the AC power source to some form of pulsating DC.
By the way, at this high frequencies some schottky diodes need to be used for.
For example I have managed to modify a small mobile phone in order to be recharged wirelessly form the Royer oscillator. See a video here:
Link2




I have a few of these laying around:

BYW29-200-E3/45 - Ultrafast Rectifier Diode

are Schottky Diodes essential in this application. Im guessing the slight amound of stored charge will delay a standard diode and create alot of head.

Thanks alot

Back to top
mister_rf
Tue Apr 24 2012, 01:36PM
mister_rf Registered Member #4465 Joined: Wed Apr 18 2012, 08:37AM
Location: Bucharest, Romania
Posts: 145
Pretty fast diodes, you should give it a try.
Back to top
Forty
Tue Apr 24 2012, 04:20PM
Forty Registered Member #3888 Joined: Sun May 15 2011, 09:50PM
Location: Erie, PA
Posts: 649
very nice data mister rf.
So basically everyone can change their resistor value to save a little power and not have it affect the results. pretty useful. I'm also surprised that such different mosfets yielded approximately the same results. One question though: what was your power supply and was it current limited?
Back to top
mister_rf
Tue Apr 24 2012, 09:25PM
mister_rf Registered Member #4465 Joined: Wed Apr 18 2012, 08:37AM
Location: Bucharest, Romania
Posts: 145
For the initial tests I have used a variable regulated power supply, 0-30V output, 3A current limiting.
Later I have used a 12V/2A power supply. (But you can use almost any 10-15V/1A power supply for this purpose).
Back to top
radhoo
Mon Apr 30 2012, 11:40AM
radhoo Registered Member #1938 Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 699
mister_rf wrote ...

In order to power up a small DC fan you need to use a rectifier bridge.
The purpose of the rectifier section is to convert the incoming alternating current from the AC power source to some form of pulsating DC.
By the way, at this high frequencies some schottky diodes need to be used for.
For example I have managed to modify a small mobile phone in order to be recharged wirelessly form the Royer oscillator. See a video here:
Yes but you still use a wire connected to the phone, so why not plug it to the wall directly?

The idea is to use a modified battery that also includes a small receiver coil, a capacitor and a fast rectifier.
Back to top
mister_rf
Tue May 01 2012, 08:12AM
mister_rf Registered Member #4465 Joined: Wed Apr 18 2012, 08:37AM
Location: Bucharest, Romania
Posts: 145
There are no wires outside the phone. That’s a wireless charger. cheesey
All items were included in the phone case = receiver coil + capacitor + schottky bridge rectifiers + 5V step-down converter (LM2678-5).

There’s only one major problem, because of the circuit high frequency (~1.6MHz) you need to place the receiver coil (that it’s inside phone case) very near to the transmitter coil. shades


1335859823 4465 FT74096 5v Ps
Back to top
radhoo
Wed May 02 2012, 08:50PM
radhoo Registered Member #1938 Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 699
In this case, congrats, you've got a compact wireless charger! Would love to see some pics of the inside of the phone.
Back to top
mister_rf
Thu May 03 2012, 06:52AM
mister_rf Registered Member #4465 Joined: Wed Apr 18 2012, 08:37AM
Location: Bucharest, Romania
Posts: 145
Need to mention this sort of experiment was not properly prepared at that time. wink
Normally, to get the best results, we may first try to adapt some sort of LC antenna into the phone case and second step to modify the transmitter frequency to match the receiver one. Otherwise it’s time consuming just finding proper capacitors to boost more energy.


Here are some phone pictures, (you can see this was not prepared for marketing cheesey ).

First a dc-dc converter assembly was squeezed in the place of the old speaker (no PCB, just wired on place, and the old speaker replaced by a smaller one).
Second, a picture of the first coil I have made the initial receiving tests.
And the last one, a picture of the new antenna made of some copper foil.

1336027764 4465 FT74096 C1

1336027765 4465 FT74096 C2

1336027765 4465 FT74096 C3
Back to top
Monir
Mon May 07 2012, 06:52PM
Monir Registered Member #3680 Joined: Wed Feb 09 2011, 12:48PM
Location: Porto Alegre - RS - Brasil
Posts: 3
mister_rf wrote ...

I have tested this circuit and it works very well. smile
In use :
-STP60NF10 power MOSFET transistors
Link2
-diodes: SR810 (100V/8A) and STTH3R02.
Link2
-Rg = 68 ohms/3W , but later increased to 100 ohms /2W
-Radio frequency chokes ~ 150uH.
You can see the results here:
Link2

1334754471 4465 FT74096 Sch Royer 2




Did you used on the video project the 12 relay and the capacitor C7? This itens are on the schematic but I 'cant find it on the video.

Thanks
Back to top

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob

Go to:

Powered by e107 Forum System
 
Legal Information
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.