Can a 3v motor take 4.8v without blowing?

londonTiger

basically I have a 2xaa milk frother which I use for my coffee.

Even at 3v which is the max volts for 2xaa it doesn't do a good job of it, but I use rechargeable batteries which has max output of 1.2v but then it drops pretty fast to 1v.

I tested it a few hours ago, put 4 batteries in and then closed the circuit with a spoon. A lot more powerful and a lot more effective.

I'm thinking of buying two of these. http://www.ikea.com/gb/en/catalog/products/30100041/

And joining the battery packs together to fit 4xaa batteries. hehe.

Do these motors have tolerances to take these kinds of volts, or will the motor break down over time? I'm hoping this is very simple mechanics involved and it doesn't break down or anything. Any thoughts?

epninety

londonTiger wrote: »

Any thoughts?

Stop polluting your coffee with milk?

Chances are the motor will be fine in the short term, short runs means it probably won't overheat and damage itself. Accelerated brush wear due to overspeed is likely to be the biggest problem.

However, they cost a quid - go try it for a few weeks/months, then come back and tell us how you got on!

You can buy 3V AA batteries, but a dozen new frothers would be cheaper

londonTiger

epninety wrote: »

You can buy 3V AA batteries, but a dozen new frothers would be cheaper

yes I've considered that, but it's not really an affordable option. £6 for a pair.

rmg1

I agree with epninety.
The motor will be fine (it will just overspin and probably get hotter than it should) but I'm fairly sure you won't damage it.
As motors are fairly cheap anyway, I'd say give it a go ..... or "Stop polluting your coffee with milk"

londonTiger

i did it, i tried to cut right up the top of one and the bottom of the other, and i assumed it was going to do the trick, but I was left with about 5mm gap. so the joint wasn't as neat as I'd liked, i couldn't join it directly so I had to use another plastic piece to bridge the gap and then duct tape over it.

so far so good, rechargable batteries are on 0.1v so need to charge them up. its gonna be for very light use, maybe 1min max a day, so shouldn't get knackered..

btw. first time in ikea, picked a few bits and bobs up, took it home, then i realise how cheap that tat is, my god...looks decent in shops, and then you bring it ome and compare the quality against your non ikea stuff and realise what crap it is.

neilwoods

As said above, it will eventually destroy the motor and will run hotter than normal. By increasing the number of cells, you are also increasing the amperage, not much but enough.

paddyrg

neilwoods wrote: »

As said above, it will eventually destroy the motor and will run hotter than normal. By increasing the number of cells, you are also increasing the amperage, not much but enough.

The current (amperage) is a factor of the voltage and resistance. If you treat the motor as a simple fixed load, the current through the load will raise directly with voltage across it. The power consumed will vary with the square of the current, and it is this power which will potentially overheat the motor and shorten its life.

In reality, it's probably not going to be an issue, but there may be a reason why the manufacturer chose a 3V system as opposed to a 4.8V one...

Nilrem

If it's the sort of motor commonly used in toys, the chances are it's rated for a voltage between 1.5 and 6v, but may overheat if used too long, as IIRC the motors are meant to be aircooled, and normally when used at a higher voltage there will be an airgap or similar to let it cool (rather than having it snug in a plastic housing).

The chances are the manufacturer chose the voltage based largely on what would give it a reasonable RPM, and partly on the desired size of the battery housing (the batteries largely determine the size of small, simple devices, so making it to take 4 batteries instead of two, would likely nearly double the size of the unit).