Lifting Electromagnet Solenoid Project

[jsvwx]

Hi,

I'm looking to add this 88 LB (40kg) Magnet Electromagnet Solenoid to hold together this gate for a bike project. When magnetized, the electromagnet will hold the steel plate on the gate and when de-energized the gate will drop flat onto the ground.

I'm looking for a circuit diagram to wire this. Aside from a 12VDC battery source, a switch and the electromagnet, what else would I need? I'm guessing a relay, cap and diode maybe? Someone who I met once and had built one of these circuits gave me a 16VDC 33000uF cap to use, but I just want to verify this. Any help preferable with a circuit schematic will be appreciated. Also if you can provide the specs of the parts needed to make sure I buy the correct parts.

Thanks!

 

[kpatz]

Looks like in your application it's an electromagnet, not a solenoid. But for the purposes of discussing the circuit that doesn't matter.

What are you going to use to activate or deactivate the magnet? A switch? A button? A signal from something? That will largely dictate what kind of circuit you'll need.

If you're just using a switch (flip on, magnet engages, flip off, magnet disengages), all you'll need is the battery, the magnet, and the switch (make sure the switch is rated for the amount of current the coil draws).

You'll only need a relay if your switch can't handle the current, or you need to switch the magnet on and off electrically. You'll only need the diode if you are controlling the relay coil with a transistor or other semiconductor (IC, etc).

This looks to me like a starting gate for a bike, right? So, you would latch the gate (magnet on), and then when you're ready to go, hit a switch and the gate releases? A self-latching relay circuit would be ideal for this. When you set up the bike in the gate, you'd push one button to activate the electromagnet and close the gate. Then to release the gate, you'd press another button. Once the gate is released, the circuit stays off until you press the start button again. That way you save battery power once the gate is released.

Here's a sample schematic I found on the web:

In your case, you'd be using a 12V battery and relay instead of AC. For the start button (this activates the magnet), use a normally-open pushbutton, and for the stop button (releases the gate), use a normally-closed pushbutton.

 

[jsvwx]

Looks like in your application it's an electromagnet, not a solenoid. But for the purposes of discussing the circuit that doesn't matter.

What are you going to use to activate or deactivate the magnet? A switch? A button? A signal from something? That will largely dictate what kind of circuit you'll need.

If you're just using a switch (flip on, magnet engages, flip off, magnet disengages), all you'll need is the battery, the magnet, and the switch (make sure the switch is rated for the amount of current the coil draws).

You'll only need a relay if your switch can't handle the current, or you need to switch the magnet on and off electrically. You'll only need the diode if you are controlling the relay coil with a transistor or other semiconductor (IC, etc).

This looks to me like a starting gate for a bike, right? So, you would latch the gate (magnet on), and then when you're ready to go, hit a switch and the gate releases? A self-latching relay circuit would be ideal for this. When you set up the bike in the gate, you'd push one button to activate the electromagnet and close the gate. Then to release the gate, you'd press another button. Once the gate is released, the circuit stays off until you press the start button again. That way you save battery power once the gate is released.

Here's a sample schematic I found on the web:

In your case, you'd be using a 12V battery and relay instead of AC. For the start button (this activates the magnet), use a normally-open pushbutton, and for the stop button (releases the gate), use a normally-closed pushbutton.

Thanks!! That's exactly what it is - it's a BMX starting gate. So can you please verify what components I'll need. The electromagnet i found is the :

88 lbs (40kg) Lifting Force
12VDC, 10 Watts, Continuous Duty
Thread Size: M5 (mounting screw included)
Lead Length: approx. 10"

Aside from the electromagnet mentioned, I would need a 12VDC battery. Can I use a 12V HD lantern battery or similar? Also would I need the relay or are the NO and NC pushbotton switches enough? Do I also need a diode across the switches? Someone had also given me a 33000uF cap once to use for this circuit. Do I need the cap?

If possible, can you PLEASE list for me the exact parts I would need? I don't want to order the wrong items.

Thank you!

 

[kpatz]

A 12V lantern battery is typically around 7200 mAH (based on what I found on the internet). Your solenoid draws about 830 mA if the 10 watt rating is accurate. You'd get maybe 8 or 9 hours of on-time out of a lantern battery. If the gate is only going to be powered for a minute or so at a time, it should be good for 400-480 uses.

If you use the latching circuit you'll need a relay since that's what keeps the circuit energized after pressing the start button. Any DPDT (double-pole double-throw) relay, or DPST-NO (double-pole single-throw normally-open) relay with a 12V coil and 1+ amp contact rating will work.

Here's one example: http://www.mouser.com/ProductDetail...=sGAEpiMZZMtSzCF3XBhmW020aja5VPfLlRrzEBEm6Ig=

As for pushbutton switches, I can't recommend a particular one since they come in all different sizes, shapes, and colors. These ones at Radio Shack would work, though they're on the small side:

Normally Closed: http://www.radioshack.com/product/index.jsp?productId=2062540&clickid=prod_cs
Normally Open: http://www.radioshack.com/product/index.jsp?productId=2062539&clickid=prod_cs

They also carry a SPDT switch, these can be wired to be N/O or N/C: http://www.radioshack.com/product/index.jsp?productId=2062541

Whatever buttons you get, make sure they're the momentary kind and not the push-on-push-off kind.

If you're going to go to Radio Shack, you can get the relay there too: http://www.radioshack.com/product/index.jsp?productId=2049720

You won't need diodes or the capacitor.

 

[jsvwx]

A 12V lantern battery is typically around 7200 mAH (based on what I found on the internet). Your solenoid draws about 830 mA if the 10 watt rating is accurate. You'd get maybe 8 or 9 hours of on-time out of a lantern battery. If the gate is only going to be powered for a minute or so at a time, it should be good for 400-480 uses.

If you use the latching circuit you'll need a relay since that's what keeps the circuit energized after pressing the start button. Any DPDT (double-pole double-throw) relay, or DPST-NO (double-pole single-throw normally-open) relay with a 12V coil and 1+ amp contact rating will work.

Here's one example: http://www.mouser.com/ProductDetail...=sGAEpiMZZMtSzCF3XBhmW020aja5VPfLlRrzEBEm6Ig=

As for pushbutton switches, I can't recommend a particular one since they come in all different sizes, shapes, and colors. These ones at Radio Shack would work, though they're on the small side:

Normally Closed: http://www.radioshack.com/product/index.jsp?productId=2062540&clickid=prod_cs
Normally Open: http://www.radioshack.com/product/index.jsp?productId=2062539&clickid=prod_cs

They also carry a SPDT switch, these can be wired to be N/O or N/C: http://www.radioshack.com/product/index.jsp?productId=2062541

Whatever buttons you get, make sure they're the momentary kind and not the push-on-push-off kind.

If you're going to go to Radio Shack, you can get the relay there too: http://www.radioshack.com/product/index.jsp?productId=2049720

You won't need diodes or the capacitor.

Thank you very much!!