by williamssteve » Wed May 28, 2008 8:44 pm
Hi
I'm running a smacks booster in my aging ford 2L OHC engine with 200,000+ km on it. So far I have seen an increase in power running
the HHO, but *no* fuel economy increase. It may be the car is old and this may stop any reall efficiencies, but the power is most welcome. The gas outlet is mounted in the air inlet to the carburetor.
I'm pulling 30 Amps when hot, about 20 when cold. I have built a PWM motor speed controller kit, I ripped out the lame 10 Amp MOSFET, and replaced it with one with 170 Amp capbility ( these MOSFETS are designed for car electronics like ABS control
MOSFET info :
International Rectifier IRF1405 MOSFET
Max voltage 55 Volts DC
max current 169 Amps DC ( max pulsed DC current 680 Amps )
BUT - YOU NEED A STONKING BIG 2 inch x 2 inch HEAT SINK TO ABSORB THE HEAT FROM THIS THING, ESPECIALLY AT LOW DUTY CYCLE. IT GETS DAMN HOT.
I have mounted the PWM contols and MOSFET inside the cab so on a hot day, the aircon will cool the unit or on a cool day you can turn on your normal heater fan to blow cool air across it.
I am going to do a gas output test on straight DC and PWM DC and will let you know. One thing to consider is making sure the tests are done one after the other quickly, as the water mixture in the booster will heat up and affect the results.
The other thing is the true RMS value of current througha PWM is different to stratight DC - from memory there is a calculation method that uses duty cycle and peak current to calculate the actual watts/sec power consumption. I ahve seen figures that suggest the indicated amps on an Ammeter measuring PWM current , measures the current approx 1/3 lower than what it really is, because of the nature of the current flow and the ammeter is an anlogue device.
Let me know how you go. I'll post my results soon.
Cheers
SW