Electrolysis is driven SOLELY by the current flowing through the cell. The lower the resistance of the cell, the lower the voltage required to produce a given amount of current.
For maximum efficiency you DO NOT want the cell to produce heat. This means that you'll need lot's of electrode surface-area in each cell.
You'll also need a GOOD electrolyte. A light Lye solution (sodium hydroxide) will work just fine.
You can make a simple cell by using two large stainless plates of equal size with a separator membrane (artificial chamois from the autoparts store). Leave about 1/8" of space between each plate and the membrane. You'll end up with about 3/8" overall distance between the plates.
The two plates must vent at the top into two different gas outlets that are isolated from eachother.
Place about 400uf (electrolytic) of capacitance across the two plates in that cell.
You can push about 10amps per square inch MAX before you start making heat and reducing the efficiency.
You power supply, for the best outcome, should be a pulsed DC supply. A standard PWM chip is used to control a power transistor to produce what you need.
The transistor emitter is connected to a heavy inductor. The other end of the inductor goes to the positive on the cell capacitor. A heavy current recifier diode is connected in reverse-bias mode with it's cathode connected to the transistor emitter and it's anode connected to the cell capacitor negative.
The negative lead from your power-supply is also connected directly to the cell-capacitor negative.
The power supply voltage is not critical in this instance, but using higher voltages will allow greater flexibility when you build the system larger.
Here's how you adjust it. Make all your initial adjustments with your scope across the inductor.
- Set your PWM duty-cycle and frequency to their minimum settings.
- Gradually turn your duty-cycle (ON time per pulse) up until you reach the point where you see the top of the waveform becoming a DC "flat-line". Then back off the duty-cycle to get rid of that DC line. This is your ABSOLUTE MAXIMUM position for duty-cycle before the system starts wasting power. Mark it and don't ever exceed it.
- Leaving the duty-cycle at the max setting, turn your frequency up gradually reduce the space between the pulses on the scope. Get the frequency as high as you can without letting the pulses overlap. This is your ABSOLUTE MAXIMUM frequency setting. Mark it and don't exceed it.
You should now see some gas being generated. You can place an ammeter in series between the capacitor and the cell plate to monitor cell amperage. If your cell is getting hot, back off on the frequency a little. Keep backing off until you don't see any cell temp increase. This is the most efficient gas production point.
If you want to further increase your gas production efficiency, find a way to introduce EXTERNAL warming of the cell(s) while they are running in this thermal "sweet spot".
4. Don't automatically believe most of what you read on the web about hydrogen production.
Try it this way and you'll see that most of those so-called hydrogen "experts" are overlooking some very basic principles in their haste.
For expanding the system, make more cells just like the first, with a single capacitor across the plates. Wire the cells in SERIES. Connect the positive pulse-supply output to the topmost cell positive and the supply-negative to the bottom-most cell negative.
Each cell needs a minimum of about 2 volts. So, for a 12v supply, use a max of 5 cells in series. This gives you a tiny bit of voltage overhead to account for resistance anomolies that might crop up from time to time in the cells.
Most important, don't blow yourself up. Homemade hydrogen and oxygen are dangerous toys.
I still believe you're better off just buying lots of batteries and storing your power in a relatively safe ionic solution. Easier to use this way too.
