Specifications:

• L: 3-3/4" W: 1-5/8" H: 1".
• Motor Speed Controlled via a potentiometer.
• For DC motors 12 to 32 Volts DC @ 5 Amps as constructed. The IRFZ44 Mosfets can handle up to a maximum 49Amps, but PCB trace capacity would have to be beefed up with some hookup wire (underneath the PCB) soldered between the MOFSET pins and the screw terminal blocks.  If you are running beyond 5 Amps and the MOFSETS are getting hot, bigger heatsinks should be used.  You can also dissipate heat with a cooling fan directed over the heat sinks.
• Requires operating voltage of 6 - 32 VDC.
  (Need a Power Supply?)

This PWM DC motor controller circuit can be used for generating hydrogen,

Oxygen Sensor Adjustment - General Information

Almost all modern vehicles, either fuel injected or carbureted, employ oxygen sensors to tell the vehicle's computer if the air/fuel mixture is too rich or too lean. The computer uses the information from the 02 sensor to determine if more or less fuel should be added to the mix in order to maintain the correct proportion.

Most vehicles are designed to operate at an air/fuel ratio of 14.7 to 1. When these proportions are being supplied to the engine, a certain amount of oxygen will be detected in the exhaust by the 02 sensor, and this information is fed into the vehicle's computer. If more oxygen is sensed, the computer thinks the mixture is too lean (not enough fuel), and adds fuel to the mix. Likewise, if less oxygen is sensed, the computer thinks the mixture is too rich (too much fuel) and cuts back on the fuel fed to the engine. This is actually an artificial relationship, but has been found to be workable with the existing techniques of burning fuel in your car's engine.

There's a big problem with this scenario as soon as you start adding a workable fuel efficiency device. For any given air/fuel ratio, burned more efficiently, the oxygen content in the exhaust will rise. If you have two or more efficiency devices installed, even more oxygen will be present in the exhaust. The oxygen content rises as the fuel is burned more efficiently for a number of reasons. Chief amongst these are a) less fuel is being used to produce an equivalent amount of horsepower, and b) less oxygen is being consumed to create carbon monoxide in the exhaust. The bottom line is there is more oxygen in the exhaust as the fuel burning efficiency is increased.

So, now that we have spent time and money to install a fuel efficiency device or two, and we are getting a more efficient fuel burn, what does the vehicle's computer do? It dumps gas into the mix in an attempt to get an oxygen reading in the exhaust equal to it's earlier, inefficient setup. This will then negate the fuel savings of just about any efficiency device, and in some cases will actually cause an increase in fuel consumption, despite having a workable fuel efficiency device.