variable resistor to control Shurflow?

[Alvin]

Anyone try to use a pot to control a shurflow pump? I would like incar adjustablity..

 

[salvageV6]

You'd prolly need something like a 0-2 ohm pot. rated for 100 watts.

One of those big knobs like they use in the old monster movies.

Nice fan cooled box to put it in.

PWM for variable control, maybe pick up a used SMC controller or make one.

For just one setting to lower the output try a .5 ohm resistor.

This is probably what I will use in my first stage M10 nozzle to avoid surging.

After that it's more nozzles and crank that pump WOT.

 

[Razor]

Here here.. resistors dont work well at controlling pump speeds. As the pressure goes up, so does the current it draws. The greater the current, the higher the voltage drop to the pump. Kinda ass backwards

PWM is the only way to fly.

 

[Alvin]

I've got an addition injector driver i could build, but would rather just slow the pump down a bit..

The idea is to do away from that pressure valve.. That pulsing can't be good..

I do have a nice regulated setup, it would be easy to do a boost referenced regulator too.. just the damn pump shutting on and off bothers me

 

[salvageV6]

Bothers me too.

I use a .5 ohm resistor at 50 watts and it works okay with an M10.

As the pressure goes up I want the voltage to go down.

Maybe they control better.

After the first stage M10 you don't need any control anyway.

 

[Alvin]

So i'm guessing radioshack doesn't have a variable resistor rated for this many amps?

How does a variable resister rated for household use work?

I guess some sort of switch for a power tool might work also.

 

[salvageV6]

What kind of variable resistor for household use are you talking about?

Dimmers are electronic, similar to PWM controls and made for A/C.

Junk and used parts houses have that stuff sometimes cheap.

A good brand new 100 0-2 ohm pot. is prolly around $80.

Junk suppliers if you can find one would have them for $5 or so.

You only need one or two points of control tops, use fixed resistors and a switch.

They are more readily available junkwise too.

 

[Torg]

It's also easy to go boost referenced pump speed, just tell Julio to set you up. Then you put it in, dial it in, & start grinnin.
Torg

www.alkycontrol.com