EM set-up advice
EM set-up advice
(OP)
Hi,
I need a small portable battery powered EM that will hold about 75lbs. It is crucial that the EM and battery(s) it uses are absolutely as light as humanly possible. Will need to use it about 3 hours continuously. Battery will need to be rechargeable. Suggestions?
I need a small portable battery powered EM that will hold about 75lbs. It is crucial that the EM and battery(s) it uses are absolutely as light as humanly possible. Will need to use it about 3 hours continuously. Battery will need to be rechargeable. Suggestions?





RE: EM set-up advice
If it's going to be holding 75 lbs, then why does it need to be a lightweight electromagnet? Obviously the answer is 'for when it's not holding the 75 lbs.' But you can see why the designers of most such electromagnets probably don't spend a lot of time making them very lightweight.
The battery system should be easy these days. eBay is awash with inexpensive and powerful Li-ion cells, holders, rechargers, etc. You'll want to consider battery safety and cooling. Especially if this is going into a confined space along with humans, such as a mini-sub's ballast system.
Obviously, start your market search for the electromagnet. Meanwhile study the batteries on the market to coordinate their capacity.
RE: EM set-up advice
RE: EM set-up advice
Finding a solenoid is probably best approached with Google.
Meanwhile, go to ebay and review Li-Ion batteries. You can use the PN 18650 as a starting point, not necessarily the optimal choice. Beware that the OEMs and sellers tend to exaggerate the mA-hours a bit.
RE: EM set-up advice
RE: EM set-up advice
That PN is just an example of a high power Li-ion rechargeable cell that is very cost-effective (often only a few dollars each) and readily available from Internet vendors. That PN is a good initial placeholder for the top of the list of possible cells, if and until you find something better.
You could look into Li-Poly cells too. They might be lighter weight per unit power since they're often not wrapped in a metal case. They're a bit more dangerous.
PS: You've slipped back to using the word "hold" again, vice "pull".