DC Fuel Pump Controller
DC Fuel Pump Controller
(OP)
A hypothectical DC fuel pump is rated at 12volts/12amps and of sufficient power to maintain 39psi fuel rail pressure? The same pump is also safe to operate at 18volts.
With some kind of a controller (PWM?), could the pump then be run at 18volts/8amps and and still have enough power to maintain 39psi?
I'm not sure what kind of a trade off there is in rpm/torque with the two different configurations.
If it is possible, what are the advantages/disadvantages of the 18/8 config as opposed to the 12/12 config, if not, never mind!
....and yes of course, I don't know squat about electrical/electronic stuff!
Thanks/sorry!
John





RE: DC Fuel Pump Controller
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If we learn from our mistakes I'm getting a great education!
RE: DC Fuel Pump Controller
Thanks Scotty!
John
RE: DC Fuel Pump Controller
Keith Cress
kcress - http://www.flaminsystems.com
RE: DC Fuel Pump Controller
John
RE: DC Fuel Pump Controller
RE: DC Fuel Pump Controller
Hi Operahouse,
I once stayed at the Hilton Hanoi Opera hotel, right next door to the operahouse.....same one?
Anyway, 12A was used only as an example......I have no idea what it actually is.
I did have a returnless system in mind when I asked the questions.........I was trying to
understand the threory of operation of the Kenne-Bell BAP.
ht
I found this 2003 post from Kenne-Bell and posted it on a forum and subsequently got crucified for it!
"As an engineer, we hope you'd agree that higher voltage = less current (less heat), so as long as the voltage limit of the windings isn't exceeded, this will result in a cooler running motor and longer pump (motor) life. The BAP is the component in the system that does all the current handling on its input side to regulate and step-up the output voltage, so virtually all the heat is used up there, not in the pump. Everything we've seen to-date indicates the BAP is practically bullitt proof and is very safe for your fuel pump."
Oh well!
Thanks!
John
RE: DC Fuel Pump Controller
RE: DC Fuel Pump Controller
Actually this is in regards to a *returnless* fuel system......there is no old style regulator that returns excess fuel to the tank....its a one way trip. The "new regulator" consists of software in the EEC, a fuel pump driver module (FPDM) and a fuel rail pressure sensor. The BAP only kicks in at a certain manifold/boost pressure.
Thanks!
John
RE: DC Fuel Pump Controller
That thing is designed to increase the pump speed so that more fuel volume is available when it's needed.
RE: DC Fuel Pump Controller
Could a fixed voltage of 18v be used and then some kind of a control system be used to control pump speed/torque by limiting current?
This way 3 pumps could be used without overtaxing the existing wiring, connectors etc?
Thanks all!
John
RE: DC Fuel Pump Controller
RE: DC Fuel Pump Controller
Just know that running a 12V pump on 18V will be hard on it and it won't last as long. The pump will be seeing around 30% over design voltage.
RE: DC Fuel Pump Controller
There is no need to run it at 18V all the time. You could control it with the TPS or a boost switch like the BAP so it's only pumping hard when you're really into it.
Dan
RE: DC Fuel Pump Controller
I didn't comment before but I have no idea how doing this would allow 3 pumps to be installed and yet still lower the current draw on the existing wiring and connectors. When large amounts of fuel is required the pumps will need fairly high current to keep up.
RE: DC Fuel Pump Controller
John
RE: DC Fuel Pump Controller
Would not the power of a pump running at 18v/8a be the same as 12v/12a, but use less current?
Thanks!
John
RE: DC Fuel Pump Controller
Sure, the power would be the same but this is an impossible scenario. Like I mentioned earlier, a pump that draws 12A @12V would NOT draw 8A @18V. Current goes up or down with the voltage applied.
dan
RE: DC Fuel Pump Controller
John
RE: DC Fuel Pump Controller
RE: DC Fuel Pump Controller
You can not control the current without changing the voltage.
The voltage up = current down only applies to AC motors and it only applies over a small voltage change. In these motors the speed is fixed by the frequency so they are constant speed motors which means if they are driving a constant load they will be constant power. In AC, power is proportional to volts x amps - volts increasing means amps decreasing.
I hope that clears up your confusion.
RE: DC Fuel Pump Controller
I was checking out this a week or so ago:
http://www.freepatentsonline.com/6556778.html
Thus the questions!
In any case thanks for the explanation!
John