I have a 12V DC motor that I would like to reduce the voltage to. Instead of getting the 12V or 13.7V (when car is running) I want to be able to reduce it to 5-6V. Maybe even make it so I can adjust it with a knob.
I’ve thought of using resistors but, the motor pulls too much current and would beat them resisitors up FAST.
Lemmie know what you guys think. Thanks.
make a potentiometer and set it to the current you want?
Need more info. Yes a pot could work, but it will have to be big enough.
find a rheostat. Older model trains used larger ones. What type of current does it pull. What is the load (what are you using it on)
Based on that I can give you options
PWM (pulse width modulated) instead. doesnt reduce the torque but reduces the speed. search for PWM circuit and some sample designs should pop up.
whats this for and approx what current.
Brian
Voltage = 12.4V car not running/13.7V Car is running.
Current = 3-5A~? Im not 100% But, it says in the instructions to use a 6amp fuse. I guess I could check that today.
Its for the electric water pump for my IC on my car. I bought a pump that flows too fast :oops:
My options are to either buy a lower flow motor, or to make an adjustable voltage regulator. I think building the the regulator would be more fun. I have my prototype breadboard sitting here and trying different circuits using transistors, voltage reg, a 10k pot. But, need to figure out a circuit for higher current. THe reason I’d like it adjustable is, I plan on running a big resv. and might end up needing that extra flow.
Thanks Guys
Just need the primary transistor (3906??) to be able to handle the current (Make sure to put a heatsink on it!!!) otherwise it’s the same circuits as the low-power motor speed controllers.
http://solorb.com/elect/pwm/pwm1/
even have the transistor for 10A in there; should be more than enough…
simple google search; “PWM Motor”; first page that popped up.
What type of pump is it? It’d probably be allot easier to put a bypass valve, or restriction valve (depending on the pump style).
You could also just buy an electronic one http://www.electronickits.com/kit/complete/motor/ck1400.htm
If you really want to make your own, here is an article that explains how to do it pretty well http://homepages.which.net/~paul.hills/SpeedControl/SpeedControllersBody.html
The slower the pump goes, the less the water/methanol etc. will atomize when it comes out of the nozzle. It will probably make things worse. What you need to do is get nozzles with a finer spray pattern. Also, did you get a high-flow pump or a high-pressure pump? You need a high-pressure for this application otherwise a finer spray nozzle will still dribble.
I agree with Brians suggestion. A PWM circuit is the cleanest, and most efficient way to accomplish what you want. Spec it for 50% over running current. Maybe 7amps? Check tho.
I think he is running a closed loop water filled intercooler. He’s pumping as does a radiator, not a sprayer.
+1. Its just moving fluid in a circle.
Yup, no spray just water pumping. Since I’ve only ran water through the pump, I might try to be chummy with the people at the place I got the pump, see if they’d let me trplace it with a lower flow. If I had a few more bucks, I’d one of the many OEM pumps for…Cobalt SS, 'stang GT’s, Sy/Ty, ect
Ahh, makes sense. I was just remembering my hard time when I sprayed my intercooler.
Thanks BTW for the replys and links. 