The Voltage Intensifier Circuit (VIC) is the term Meyer used for the final components of his water fuel cell. These particular parts have caused a lot of consternation in the water fuel cell research community, as the physical design and electrical values of the components vary greatly, and can be manufactured and used in many ways. Here I’ll discuss my thoughts and efforts in this area. Please comment on this!
The first drawing is the minimalist example of the MOSFET drain-source circuit (driver circuits for MOSFET gating will not be discussed here, those can be very convoluted and the one I’m using for the Oscillation Overthruster is working just fine). In this circuit, a MOSFET gates a positive potential to ground. Nothing else is really needed. However, this leaves a lot of room for stray voltages from various sources, some will damage the MOSFET if left unchecked. A more “complete” version is shown in the augmented MOSFET output circuit, which includes
* a regulator diode, which ensures that total potential is never reversed
* a clipping diode, which “shorts out” reverse currents across the VIC primary due to magnetic feedback
* a “PTC” device, this is a “resettable fuse” which protects the MOSFET from over current at the price of a small amount of resistance
* a zener diode, this “shorts out” reverse voltages across the MOSFET drain/source. Some MOSFETs (like the STP8NK100Z) have internal zeners which perform this function.
Many would argue that some of these components would not be very beneficial, and would even hurt the purpose of the circuit, I do not dispute this. In particular, some experimenters would not use the clipping diode as clipping the buck feedback from the VIC primary will definitely affect performance. I’ve added the PTC myself, as the cost of these devices is far cheaper than MOSFETs, and turning the dwell up just a little too high is very easy. It’s all perspective, if you have a warehouse full of 20-year-old junk 10GB SCSI hard drive controller PCBs with BUZ11 MOSFETs all over them, then by all means… burn out as many MOSFETs as you want. If you’re paying $5 apiece for them, a 40 cent protection diode starts to look pretty good. Diodes, zeners, and PTCs that handle the wattages and voltages used here are not expensive. Some experimenters are using MOSFETs that I cannot find for under $25.
On the Oscillation Overthruster design, I’ve allowed a lot of freedom. Some components are not required, others can be shunted with bare wire, and I’ve allowed two sizes of PTC for mounting on the PCB. All of the heavy transistors are TO-220 types and can be socketed and (MUST be) heat sinked.
Next on the schematic, I show the quintessential Meyer VIC circuit. The bottom choke is adjustable, either through a wiper arm in contact with the wires along the side of the coil, or through multiple taps along the choke which can be switched manually.
The other drawings on this schematic show various ways to actually connect the water fuel cell to the MOSFET. You can use a VIC transformer, or not. You can use chokes, or not. The blocking diode is recommended, but is probably also optional (try and find out!). If you use a single choke device with two windings on it, I think it’s called a “bifilar” choke (I think it’s a term Tesla used?) and you can hook that up two ways.
Okay, lots more pictures now…
Left to right: roll of 1/2″ wide Scotch 92 kapton tape, small ‘E’ core with plastic bobbin, Epcos D-core 47mH 1.3A choke (Digikey 495-2790-ND), cheap measuring scale, JW Miller / Bourns 8116-RC 50mH 2.3A choke (Digikey M8911-ND), 3/8 x 4 inch ferrite rods
|POWERLITE C-cores with scale, label from Elna Magnetics.
Left to right: wrapped AMCC-100, two parts of AMCC-320 sitting on oiled anti-corrosion “gun” paper (note light rust on end), AMCC-100 set (this set is varnished with Corona Super Dope)
These are very strange things. They are made of nanocrystalline amorphous metal in the form of extremely thin ribbons of iron alloy wrapped to make the oval, then cut through the center. By extremely thin, I mean on the order of 25 micrometers. These are by Metglas and I got them through Elna Magnetics.
|POWERLITE C-cores – AMCC-100 closeup in sun. Notice the edges of the thin iron ribbons are somewhat visible on the edge. This is painted with Corona Super Dope.|
|Ferrite rods in the sun, see the shiny sparklies? Not really, it didn’t come out in the picture, but they do sparkle.
Two are 3/8 inch by 4 inches, the one on the right is 1/2 inch by 7 1/2 inches.
|Toroids: large yellow T400-26D (4 inch diameter) wrapped with Scotch 92 dielectric tape and a few turns of 20 AWG enameled copper wire, and Amidon ‘pulse’ toroid, pretty much the largest one they sold. The Amidon toroid is smooth and hard, makes a nice ring when struck lightly.
Honestly, I’m not sure if I can ever use these, they’re just too hard to wrap. I can make a jig I suppose, but my attempts at locating a reasonably priced toroid winding machine were futile.
|Left: various colors and gauges of copper magnet wire.
Right: 3 BUZ11 N-channel MOSFETs in the middle of a power supply PC board from a 10GB 50-pin SCSI hard disk drive, circa 1994. These will be harvested and reused. You thought I was joking, didn’t you? I just have this one, not a warehouse full
|TRIAD VPS10-8000 power transformer, front and back.
This is a 115VAC/230VAC to 5VAC/10VAC 80 watt power transformer. The ‘primary’ is made to take wall voltage 115/230 volts, and step that down to 5 or 10 volts. As shown, both sides are hooked in series, so it’s wired to take 230VAC and put out 10VAC. I use it backwards, so my input is 12V pulsing and output is… well, messy… but usually a few hundred volts with some very high spikes. Pulses go off the scope at 50 volts/division with 8 divisions.
Off topic: get a load of the cat hair stuck in the solder flux on the bottom right tab on the back.
|Ferrite rods, one raw, one wrapped with dielectric tape and then 2 windings (and again covered with dielectric tape) plus one small ‘pulse pickup’ winding with a relatively large gauge
I’m suspicious that this is too large, it measures 1.75 milliHenries a side. When I wrapped one of the 3/8″ rods, it measured 130μH a side, which seems more likely to be closer to a good value.
Not pictured: two sheets of 12″x12″ teflon, one 1/8″ thick and one 1/16″ thick. These are for use as insulators on the ferrites or the C-cores. They are white and square and boring, so I didn’t take a photo of them.
So I’m trying to get the TRIAD transformer to work. It’s not cooperating. I was hoping to use relatively simple off-the-shelf parts to get this working, that’s why I’m considering it at all. I don’t think this stuff is so hard that you can ONLY do it the SAME WAY, but I might be mistaken. Lots to try before giving up on that.
When I hook it up, the voltage just goes to naught. With the circuit off, I can verify very low resistance conductivity through the coils, I can verify the diode conducts only one way, everything seems to be just fine… but the actual voltage present on the water capacitor is a few millivolts. I’ll hook this up again and take another picture.
Quick edit: the rewiring is working, not sure what to make of it yet. Basically I’ve temporarily eliminated the hookup box I’ve been using so I can just plug wires into the breadboard.