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Topic: SORTED Looking for small electromagnet (Read 2787 times) previous topic - next topic

JimboZA

Dec 31, 2012, 11:58 am Last Edit: Dec 31, 2012, 01:36 pm by JimboZA Reason: 1
(OK, I know it's not a sensor, it's an actuator, so mods feel free to move this thread  :D)

I'm thinking of using an electromagnet on the end of a robot arm to pick stuff up. So far the smallest one I found is here (14kg lift) but a tiny one that can lift a few 100g would do.

I know I can make one with an old nail and some wire, would rather buy one.

Anyone know of suppliers of small ones please?

TIA,

Jim
Johannesburg hams call me: ZS6JMB on Highveld rep 145.7875 (-600 & 88.5 tone)
Dr Perry Cox: "Help me to help you, help me to help you...."
Your answer may already be here: https://forum.arduino.cc/index.php?topic=384198.0

dc42

Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

JimboZA

Thanks dc.... I always forget ebay!

But as it happens, I remembered there was one in my junk box. It came out of a copier / printer that I stripped- I think it was part of the door latch or some other kind of interlock safety thing.

It has no label so I took a flyer and threw about 10VDC into it and it seems to work.
Johannesburg hams call me: ZS6JMB on Highveld rep 145.7875 (-600 & 88.5 tone)
Dr Perry Cox: "Help me to help you, help me to help you...."
Your answer may already be here: https://forum.arduino.cc/index.php?topic=384198.0

MarkT

For a small electromagnet consider making your own ?

Either way remember to drive it like a relay with a big enough transistor/FET and a free-wheeling diode.
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JimboZA


Either way remember to drive it like a relay with a big enough transistor/FET and a free-wheeling diode.


Yep... I might not control it from the Arduino at all, might just switch it manually straight from its power.

Bit of a hassle that these things seem to be 12v (it has no label though), but I tested it at 6v which is what the rest of the kit will use and it does work... I suppose it might not be as strong at low voltages but I want it to be able to lift a few washers or panel pins is all.

Johannesburg hams call me: ZS6JMB on Highveld rep 145.7875 (-600 & 88.5 tone)
Dr Perry Cox: "Help me to help you, help me to help you...."
Your answer may already be here: https://forum.arduino.cc/index.php?topic=384198.0

MarkT



Either way remember to drive it like a relay with a big enough transistor/FET and a free-wheeling diode.


Yep... I might not control it from the Arduino at all, might just switch it manually straight from its power.

Bit of a hassle that these things seem to be 12v (it has no label though), but I tested it at 6v which is what the rest of the kit will use and it does work... I suppose it might not be as strong at low voltages but I want it to be able to lift a few washers or panel pins is all.



At half voltage it'll be about 1/2 the magnetic field and 1/4 the power dissipation - the power saving alone is probably
valuable.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

dc42

#6
Jan 01, 2013, 01:37 am Last Edit: Jan 01, 2013, 01:39 am by dc42 Reason: 1
At half the magnetic field.it will provide one quarter or the lifting force. You can buy 6V solenoids via ebay if you need more lifting force.
Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

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