12V Pump Operating at Variable Speeds - Is It the Charger?

[HardHatMatt]

Had been hooking the blue bowl up to battery out on the back porch but finally cleared some space in the basement and decided I'd hook it straight to a charger. Trouble is, the pump seems to be operating at variable speeds...which is obviously less than ideal. The charger is a Schumacker 10A Charge/2A Maintainer. I'm suspecting that there is something about the "maintainer" aspect of the charger that is kicking the power down? Any advice is much appreciated.

 

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[Goldwasher]

Hook it up to a battery. I will steady the charge. Acts like a voltage regulator. I can't explain the science behind it lol. But, it's what I do. charger to battery and leads from bilge to battery. I just leave the negative Hooked up always. When running leave positive from charger on terminal and just disconnect lead from bilge to positive clip from charger as needed for on/off. I don't get any voltage surges.

 

[Nitric]

Probably!! I had to laugh when I saw the title! I've been through this on other things. Some charges go in "surges"(for lack of better words). I don't don't know the technical terms. I have some that came from equipment, they have a couple of settings. The maintain part of that charger can be left on something for ever without ever overcharging or hurting the battery. It has circuitry in it to boost or shutdown when it needs to.

Not sure if this is the same thing your experiencing but sure sounds like it. Something that will help is a small battery, to take up the "slack". Again, I kind of understand, just don't know the words.

 

[Nitric]

Hook it up to a battery. I will steady the charge. Acts like a voltage regulator. I can't explain the science behind it lol. But, it's what I do. charger to battery and leads from bilge to battery. I just leave the negative Hooked up always. When running leave positive from charger on terminal and just disconnect lead from bilge to positive clip from charger as needed for on/off. I don't get any voltage surges.

Hey I wasn't copying!! I posted and looked up and you posted the same thing...

Another thing that can be done, but gets too technical for me to try to even remember the terms or explain. A capacitor can be added, but I won't even attempt to try to understand or pretend to explain that one! Basically, is what the battery is doing, in a way......And can "fool" the charger. But you'll have to dig online to find what would work. Sometimes they are used in solar set-ups, and car audio and I'm sure many other things. It's been a long time since I've dealt with the problem. I'm not sure if there would be any kind of feed back, from the motor telling the charger to kick off. Probably depends on the charger and how it works. We had to experiment with caps and diodes to cure some of the problems. A small battery is the simplest cure.

Just throwing that in there, in case your like me and have piles of stuff from other projects, you might be able to make something work without buying something more...

Added...another thought! If you have some old wall plug adapters laying around, laptop chargers, older video game, and even slot car, train, etc(just to give the idea)...Some of those will work well enough to run the small bilge pumps. It's kind of hack! But some will work with no problems. the bilge pump doesn't normally have to run exactly at 12 volts DC, they will run in a "range" . Just keep an eye on things getting hot at first and if the pump doesn't run or runs backwards reverse the wires. I know it's "hack" but will work, and I'm the king of taking junk and making work somehow!! I'm stuck on those lines because I understand not wanting to have car batteries or similar charging in the house. I'm just guessing thats why you were using the charger alone in the first place..

 

[johnedoe]

Anytime you use a battery charger for a power source you really should have a battery in line.....JMHO

 

[russau]

you would think Commercial power 120 /240 volt a.c. is a steady power source BUt it isn't! Power 120 /240 volts fluctuate up and down at times.

 

[HardHatMatt]

Thanks all - very helpful all around and much appreciated!

 

[kcm]

Problem is, a battery charger may "seem" like it would work as a power supply, but it cannot. A battery charger has no means of controlling the frequency of the output. By frequency, in North America we use 60Hz, while in other parts of the world they use 50Hz for their electrical outlets. A battery can accept ANY frequency when charging, so regulating the frequency is not necessary. And since a battery charger takes 120V (+/- a few, as power grid is not constant) and turns it into 12V (actually about 14.4V), your frequency swings through the charger are amplified.

One way to vary speed on some electric motors is to control their frequency. Very common thing. Also, even though most any battery can be used in most situations like this, larger loads WILL REQUIRE a larger battery, otherwise the constant charging can heat up the battery, shortening its life or, in rare cases, overheating the battery. But for a small pump, even a battery for a riding lawnmower would probably work ok. But I would (personally) use a small car battery, or larger motorcycle battery.

 

[Goldwasher]

yep, mine is a from my old vw bug.

 

[Nitric]

Here's an article that kind of explains some of it.....

Comparing power supplies to battery chargers, explaining lead acid battery charging algorithms

 

[ClaimStake]

a few things here guys, only if the charger is a pulse charger is it going to surge. most nowadays are.

your mains power is rectified and the charger should have a voltage regulator. so if your house voltage swings by even 10-20 volts it will have no effect on the chargers output.

the only common DC motors that use frequencies. are brushless motors. here's an article;Brushless DC Motor, How it works ? ~ Learn Engineering

a simple and cheap way to get a power supply is to modify a computer power supply. they're switch mode and well filtered, lab grade power but way cheaper.

I have a couple of these rigged up for different uses works great.

to use one, make sure it's unplugged. than cut "all" the wires from it. but leave about 6 inches or so to work with.

here's the color codes for the wires. these are standard and should apply to all pc PS's;

black=ground(0v)
yellow= +12v
red= +5v
orange= +3.3v
green= power relay (turnes it on) there should be only one of these.
you don't need any of the other wires.

add a small 100ohm resistor to the green wire and connect "any" black wire to it (you can use a switch) this will power it on without it being plugged into a motherboard.

than group up all the yellow wires together and connect them to a single heavier gauge cable, like 8-10 gauge. run this cable to your water pump. positive pole(+).
do the same for the black ground wires (-0v) connect this to the negative pole of the pump.

leave 1 black wire for the green wire.

power on and you should be good to go.

put some elec. tape on the left over wires you don't use.

also loads on a circuit do not give feedback "persay". they act as resistors, which regulates the current draw from the power source. so if the resistance goes up and down than this will cause "noise" in the circuit.

feedback is actual power going back through the circuit.

 

[Nitric]

a few things here guys, only if the charger is a pulse charger is it going to surge. most nowadays are.

your mains power is rectified and the charger should have a voltage regulator. so if your house voltage swings by even 10-20 volts it will have no effect on the chargers output.

the only common DC motors that use frequencies. are brushless motors. here's an article;Brushless DC Motor, How it works ? ~ Learn Engineering

a simple and cheap way to get a power supply is to modify a computer power supply. they're switch mode and well filtered, lab grade power but way cheaper.

I have a couple of these rigged up for different uses works great.

to use one, make sure it's unplugged. than cut "all" the wires from it. but leave about 6 inches or so to work with.

here's the color codes for the wires. these are standard and should apply to all pc PS's;

black=ground(0v)
yellow= +12v
red= +5v
orange= +3.3v
green= power relay (turnes it on) there should be only one of these.
you don't need any of the other wires.

add a small 100ohm resistor to the green wire and connect "any" black wire to it (you can use a switch) this will power it on without it being plugged into a motherboard.

than group up all the yellow wires together and connect them to a single heavier gauge cable, like 8-10 gauge. run this cable to your water pump. positive pole(+).
do the same for the black ground wires (-0v) connect this to the negative pole of the pump.

leave 1 black wire for the green wire.

power on and you should be good to go.

put some elec. tape on the left over wires you don't use.

also loads on a circuit do not give feedback "persay". they act as resistors, which regulates the current draw from the power source. so if the resistance goes up and down than this will cause "noise" in the circuit.

feedback is actual power going back through the circuit.

Ya, Feedback was the wrong word. What I was trying to get at is the charger circuit sensing there was not enough. I wasn't sure if that circuit can "sense" if there isn't a load, or enough load. Or if that is just how they work.

We did something years back to "fool" the circuit in the charger. What ever it did, it stayed constant. Not sure how it worked, just knew what the charger was doing.

 

[ClaimStake]

"sense" would be the correct word.

if you put a resistor in line with the pump that should trick the charger into thinking the load, what would be a battery is low.

depends on the charger. specific design.

a battery is a power source so it does send feedback. more and more as it becomes charged. the lower the feedback the more the charger will think it's pushing a dead battery.

I would have to do some math to figure out what resistance to use. charger and pump specs are needed.

 

[kcm]

Not just DC motors. If you look at the nameplate ratings for 3-phase motors, most will have a different nominal speed for 60Hz and another for 50 Hz. There are some frequency speed controllers out there just for this purpose. ...But that's getting a bit more technical than this thread really needs, IMO.

 

[Nitric]

Not just DC motors. If you look at the nameplate ratings for 3-phase motors, most will have a different nominal speed for 60Hz and another for 50 Hz. There are some frequency speed controllers out there just for this purpose. ...But that's getting a bit more technical than this thread really needs, IMO.

I have a couple of old AC/DC Brush motors. Wonder why that never caught on. That would make life simpler!I took one apart to try to even understand how it could work on AC or DC with the same wiring. But I was completely lost! Way Way beyond my understanding, and they are fairly simple, no circuitry at all. Just windings and brushes. have a reverse lever/switch too. One day I'll have to try to understand how those work. And the only time I've seen any that would work on either AC or DC. One runs my watch lathe.

Sry. Off topic... Again.......

 

[kcm]

'Tis OK Nitric. ...Let's just go all out. Hell, who cares about topics, right?? Let's just turn this into an electronics thread.

Dang, it's been so long for me that I've forgotten most things. ...Is a good thing electricity hasn't changed much over the years or I'd be in REAL DEEP caca!!

 

[HardHatMatt]

As originator of the thread, can I officially sanction a deviation to general electrical "musings?" I enjoy trying to follow along and learn a few things. Even something as simple as attaching alligator clips to wire was intimidating for me at first...I don't know if it's the potential for shock or fire, but I've always been a little hesitant to experiment with anything electrical. Like anything else, once you understand a few basic things it is a little less daunting.

 

[Nitric]

As originator of the thread, can I officially sanction a deviation to general electrical "musings?" I enjoy trying to follow along and learn a few things. Even something as simple as attaching alligator clips to wire was intimidating for me at first...I don't know if it's the potential for shock or fire, but I've always been a little hesitant to experiment with anything electrical. Like anything else, once you understand a few basic things it is a little less daunting.

As a home "not know" anything experimenter! I can tell you a couple of things....Fire extinguishers and fuses or breakers are handy! And if you get shocked? Don't do that anymore, because that must have been the wrong way! Is something "smells" hot? It probably is don't touch it to confirm!

Most of what I learned was from trial and error! So, the above has happened many times! Call it......Shock therapy type learning! Most stuff we have around house that we play with isn't that scary. 220 or 240 still makes me nervous. And when you get into playing with solar type projects, the DC battery banks can get a little scary. You can weld tools to your project if not careful. (Not joking). I know!!! High amperage DC (and again I don't know terms) will suck you(tools) to it, ac will allow a release in a way. Ohh! And from experience? Don't play with the microwave!! I took one all apart before I learned that taking the magnets out of the magnetron(the back to the future flux capacitor of the microwave) I learned that the oxides from that can be very toxic! Beryllium oxide I think it was(can't remember).see how I tried to bring it back to prospecting topic?

 

[Capt Nemo]

All electric things run on smoke. Let the smoke out, and they don't run anymore.

I've let a lot of smoke out to get this!


When in doubt throw another megavolt across it!

 

[Nitric]

All electric things run on smoke. Let the smoke out, and they don't run anymore.

I've let a lot of smoke out to get this!
View attachment 1356078

When in doubt throw another megavolt across it!

I always wanted to build one of those!!!!!! I never learned enough!!