Make an LVDT with soda straws

Science Technology

Gareth Branwyn is a freelance writer and the former Editorial Director of Maker Media. He is the author or editor of over a dozen books on technology, DIY, and geek culture. He is currently a contributor to Boing Boing, Wink Books, and Wink Fun. His free weekly-ish maker tips newsletter can be found at garstipsandtools.com.

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November 17th, 2009 10

It’s the McLVDT, a linear variable differential transfomer, made from McDonald’s straws. The creator writes:

I made a primary coil on a normal sized straw, and made two secondary coils on the outside of the larger McDonald’s straw. Since the McStraw is large-bore (perfect for those thick high calorie shakes), the smaller straw with the primary winding fits nicely inside. The position of the inner straw can be determined by examining the amplitude and phase of the combined signals of the secondary coils, which is shown in raw form on the oscilloscope.

“Mc”LVDT

10 thoughts on “Make an LVDT with soda straws”

Matt Mets says:

November 17th, 2009 at 4:53 pm

Ha! This might make a nice linear movement sensor as well!

Bob D says:

November 18th, 2009 at 7:43 am

LVDTs are for measuring linear displacement.

Steve Poling says:

November 17th, 2009 at 9:32 pm

If you live in a town big enough to have a place to buy Bubble Tea, buy yourself a tasty beverage. And save the straw. If you think the McDonalds milkshake straws are large-bore, you’ve never enjoyed Bubble Tea.
Kevin Rouviere says:

November 18th, 2009 at 11:15 pm

Bubble Tea? I’ll have to check that out. Thanks!
Kevin Rouviere says:

November 27th, 2009 at 5:36 pm

I’ve since made a detailed article about this.

It can be found here

http://hackscape.wordpress.com/2009/11/27/mclvdt/

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Tagged Electronics Science

Make an LVDT with soda straws

By Gareth Branwyn