Recommendation for replacement cool shirt pump

#1

My 2006-era Cool Shirt pump appears to have reached the end of life. It is an Attwood V500 pump, which a quick scan indicates is no longer made.

Any suggestions as to the simplest replacement pump I can get? I’m not interested in doing much if any fab work to get it housed in the cooler tank.

Ideally the pump output flange is roughly same diameter, so I don’t have to worry about sleeving or an adapter to get it to mate up.

#2

I’ve seen guys using ebay therapy coolers for about 60 bucks, and it comes with a flow control.

#3

http://www.iboats.com/Bilge-Pumps-Submersible-200-550-GPH/dm/attr_id.3326--cart_id.182098485--session_id.651458460--view_id.669457

#4

Ended up with a 1000GPH pump from Harbor Freight for $20. Flows so fast will probably have to wire in a rheostat to slow it down.

http://www.harborfreight.com/1000-gph-bilge-pump-66095.html (Item #66095)

#5

Factory dimmer knob might handle that. That’s what I use for my helmet blower.

#6

I’m not sure that the dimmer switch will handle the current.

When I was working on my helmet cooler project, 4yrs ago I think, I went thru a number of ideas to control fan speed. I ended up having to go with a couple big power resisters because I couldn’t find a reasonably priced rotary variable resister that could dump enough heat. I think I used 2x 10W power resisters fastened to a big heatsink and it’s worked fine ever since. Not adjustable tho.

I tried several times to make a variable speed fan using the biggest rotary variable resisters (potentiometers) I could find (@Mouser) at a reasonable price. But w/o a heatsink they couldn’t handle the heat. I tried several times to fasten a heatsink to the big variable resister, but the heatsink couldn’t handle the vibration and kept coming off. Each time heatsink came off the variable resister cooked.

In the AC world it’s easy to reduce power because there’s some semi-conductor thingee that chops off the tops of the sine waves, but in the DC world all you can do is add resistance and that means heat.

#7

FWIW it’s relatively easy to design a low voltage pulse width modulator (PWM) to set the average current in the DC realm ala the AC dimmer circuits used in lighting controls in your house. Big resistors make a lot of heat in a small area. A PWM is pretty efficient.

#8

Dude, be realistic. You’re likely the only EE here. So either you design it and spec the parts for us, or it doesn’t get done. I certainly can’t do it.

#9

Hmm, definitely way past my cave-man understanding of all things electrical. Perhaps I will start out by flicking the power on/off in a cyclical fashion and see how that works for me!

I predict being frozen solid by time session starts, yet out of ice entirely by lap 3. :wink:

#10

Au contraire mon ami. Any of the guys fiddling with Arduino boards could do it. Turbo could do it. But given all the help I’ve received from everyone here in the past, when I get a free weekend I’ll take a crack at it and post the BOM and schematics. If there’s sufficient interest I might be persuaded to learn how to use one of the online layout tools and order PCBs. Do you have any load info for your helmet fan blowers or the pump motors?

ctbimmer, LMAO.

#11

The dimmer switch I used was from a newer BMW. Not sure which one because It came out of my brothers toolbox. It has at least a few rheostats in it so you can maybe run it through them parallel.

I’m not sure why you wanted to double the pump size from the factory unless your adding cool pants or passenger cooling. I did have the idea to make a beer cooler that multiple people can plug into in the paddock. :slight_smile:

I use the donjoy cooler wired directly to 12v. I think the temp control on it bypasses the water back to the cooler, but I haven’t taken it apart. I’d be disappointed if it was just pinching the line.

#12

As promised. I haven’t had time to breadboard and test this yet so feel free to contact me if you do and run into trouble. If several people are interested maybe we can work something out. Be aware that the output FET (Q1) is only sized for up to a 3A load. Depending on the load it is connected to you may also want to heatsink it.

[attachment=1956]555PWMCtrl.jpg[/attachment]

#13

Update (nice work on the schematic, BTW) but you can buy a 20A PWM controller cheap on eBay. I got three of them for my in-progress cooling project, and they handle more than 6x the current of the 3A motor (600 GPH) I am using for my shirt, so plenty of headroom. Not that it wouldn’t be fun to build :slight_smile: , but you can get them for $10-12 each.