The main function of the control unit is to provide the necessary PWM and other needed inputs to the HHO generator. This will allow us to test many different PWM configurations, leaving the electronic components unchanged. Changes to the PWM will be taken directly from program changes. In other words, PWN is controlled directly by a program.
The heart of the control unit is a programmable microcontroller which provide low current PWN signal. The duty cycle and frequency of the PWM signal is determined by the code that was programmed into the microcontroller. Later, a transistor is used to amplify the signal to the proper working current (which is limited only by car’s battery).
The system sketch looks pretty much like this:
All you need to do to change PWM values is to make minor changes in the program. In the future we will use to microcontroller to display important data to LCD screen during the work of the cell.
Part required for the HHO control unit:
1)Microcontroller – this a microprocessor system which contains program memory, parallel and serial input/output, timers and interrupts – all integrated into single chip that can be bought for as little as two dollars. To harness a microcontroller to our HHO mission basic digital logic understanding is required, plus C language knowledge is an advantage. It is possible to program a microcontroller both with assembly and C, but C is much straight forward option because it is easy to learn and remains the same even with different microcontrollers.
If you are new to microcontrollers you have nothing to worry, you can quickly close this gap because microcontrollers designed for easy learning and implementation. Plenty of learning material is available over the net and you can even read this fantastic book about microcontrollers for quick start:
Advanced PIC Microcontroller Projects in C: From USB to RTOS with the PIC 18F Series
This book helped me to become from total newbie to someone that can program his own microcontroller :]
The microcontroller of our choice is Microchip PIC18F8520 , info can be found here. It is cheap and is more than enough for our needs.
2)Mosfet Transistor - is a device used to amplify or switch electronic signals. It is used in the HHO control unit to amplify the PWM signal from the microcontroller using electric power from the battery. In this case the mosfet should be capable to work under load of at least 50 A x 12 V Continuously and at any given moment.
Data sheet of my current Mosfet transistor:
3) Set of connectors – needed to connect this HHO unit to the outer world.
4) Good metal box – can be any good looking box with enough space for components.
In future we will add to this control unit many important HHO features and the best part: no hardware changes will be required only C code supplemental.
- EFIE – In future this control unit will use as an EFIE device and will constantly find the appropriate air/fuel mixture need for HHO device.
- LCD screen – We plan to add a screen to receive valuable data output from the HHO device and/or the car work parameters.
Note: This device is not a must for running HHO system in the car but it will greatly help us to find the most economic and the most efficient regime. You can wait for our results and just implement them in you device without complications. stay tuned for updates…