Does a BLDC motor require a motor controller?

I am in need of a very small, cheap water circulating pump that can run continuous. A brush DC might be an issue though. Est life cycle is 10,000hrs but probably will never touch that. I know of BLDC motors but I would rather run this device on straight DC power to simplify my life. I guess if I could find a cheap AC pump, I could do that too.

I have found some little BLDC pumps for use as PC coolers but not sure if they need a controller.

Look up bilge pump. Many are designed for continuous operation and are BLDC with built-in controllers.

Here is what they look like: http://www.sportsauthority.com/product/index.jsp?productId=2034602&mr:trackingCode=BBBE1342-D16B-E011-92EE-001B21631C34&mr:referralID=NA&mr:filter=24486676791&mr:adType=pla&mr:ad=30774699831&mr:match=&mr:keyword=&{copy:iq_id}=&{copy:camp}=


It will require some investigation to determine confidently that the pump you decide on is BLDC.

John

A bldc pump for your needs is no more complex than a brushed pump, just make sure that the pump in question either has built in, or comes with its controller.
A pc pump is much smaller than a bilge pump, unless your talking rc bilge pump.

Yeah, we need compact and moving only roughly .1-.25gpm is fine. I am a little concerned that a BLDC pump may have extra stuff to fail if it really does need a controller to operate. Would a small AC pump be available? Seems like finding one for another purpose is better than calling any "pump companies" who seem to want to "spec" us a pump or build one special. I would estimate we need this pump to fit in a 4" cube.

Depends on your outlook, however a bldc with a controller in my opinion will be a lot more reliable than a brushed or even an ac motor, the controllers seperate or built in are usually potted - totally encased in solid 'goop' so water and cack proof, a low volatge bldc is pretty hardened against moisture too electrically.

If you want a mains ac pump then you can salvage one from a washing m/c, the benefit with these is that the impellor is usually driven by a magnet, so you can stall the pump without a burnout.