How-To: Phone Plug Tilt Switch

Cross-sections of phone plug tilt switch in open (left) and closed positions.

Here’s another cool improvised switch hack from Forrest Mims’ 1996 Sensor Projects mini-notebook for RadioShack (now available as a compilation with two other classic Mims books in Electronic Sensor Circuits & Projects).

All it requires is a spare tip/shield male connector with a removable housing, and a BB or other conductive metal ball. The version I built and photographed below uses RadioShack’s #274-286 1/8” mono phone plug (2-Pack) and a 7/32″ chrome steel ball (such as Amazon Supply’s BS-0219-C). The dimensions of the ball are not too critical.

To put it together, all you have to do is remove the housing, set the ball in place between the contacts, as shown, and then put the housing back on. I built two of these, for testing purposes; the first worked like a champ, and second one was a bit wonky until I polished the plug contacts with a Q-tip moistened with rubbing alcohol and then touched to a pile of table salt.

3 Responses to How-To: Phone Plug Tilt Switch

J. Schacher on February 26th, 2013 at 11:46 am said:

What is this? What does it do?

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- Gavin on February 27th, 2013 at 4:43 am said:
  
  Its a swich that if you connect wires to the different terminals (seperated by the sm. black line), then it allowes current to flow only if it is pointing down. otherwise, it wont allow power through.
  
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Zack Jones on February 27th, 2013 at 7:49 am said:

It could be used in app development as well. One could develop an app that does something when the phone is in the upright position ( upside-down for other models). Sure you are thinking, well what about my accelerometer and gyro? Can’t we just use those instead? Sure but this seems to be a better solution for a quick response. The accelerometer and gryo codes can sometimes be heavy and takes up plenty of the processing power due to their constant checking characteristics. In this case the code wouldn’t have to constantly check to see if the switch has been triggered, only after it shorts the connection would the program have to respond. This could be great for physical computing devices as well. Installing a headphone jack onto an Arduino prototype board is easy and you will be able to cut a system off whenever it falls or isn’t in the upright position. Similar systems are used in water pumps and also in your vehicles.

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