History of Open Dots
1928, US Patent 1,668,249, Frank Rich, “Automobile Riding Amusement Device”
The patent discloses the concept of a support surface with interspersed electrode strips of alternate polarity to supply power to a device resting upon it with a plurality of contacts to connect with the electrode strips of the support surface.
This patent discloses a large track support surface with alternately polarized electric strips upon which rideable electric cars pick up their power by dragging four electrical pickups. The patent discloses a relay method of preventing the pickups from shorting out the energized strips on the track support surface. The relays prevent shorting by forming a connection of the contacts into the circuit only when needed.
The rideable cars disclosed in this patent lose power if they are oriented at a significant angle from the direction of the strips. Because of the electrode strip spacing on the support surface, the cars lose power even when oriented parallel with the strips depending on the positioning.
The electrode strips on the support surface disclosed in this patent are energized with AC power, and the drive motors are AC motors
1930, US patent 1,779,052, Henri Souplis, “Electric Amusement Device”
Souplis described an amusement park bumper car with six contacts that dragged against the floor support surface, the floor support surface made of parallel conductive strips energized with alternate potentials. This combination of geometries guaranteed that no matter where the bumper car was positioned or oriented on the floor support surface, at least one contact would be on a “+” electrode, and another would be on a “-” electrode. Thus, electric power is conducted into the bumper car.
Souplis disclosed a method of energizing relays to close the correct contacts in order to bring power to the motor without presenting a short to the energized floor support surface. This was done with relays by necessity, because rectifier diodes were not available at the time. The strips were arranged closer together than Rich’s patent, so the connection to power was never lost regardless of the position and orientation of the electromechanical device.
Souplis’ method used AC power so that the car does not reverse direction depending on how it connects to the floor electrode strips.
The pattern of parallel electrode strips of alternate polarity, and the pattern of contacts closely resembles the Open Dots standard to a scale factor.
1955, US patent 2,717,557, Robert Seyffer, “Electrically Operated Track for Model Vehicles”
In this patent, Seyffer disclosed a track support surface employing parallel electrode strips energized with alternate electric polarity. Seyffer improved on Souplis’ complicated relay system by employing recently-available rectifier diodes to properly connect the four contact points in the vehicle to the on-board power rails. The arrangement of diodes is commonly referred to as a bridge rectifier and can be seen in his Figure 5 above.
Seyffer’s geometrical arrangement of contacts does not provide for an electrical connection to power at all orientations.
1963, US patent 3,205,618, Solomon Heytow, “Remote Control System for Toy Automobiles”.
Heytow discloses a track support surface of parallel electrode strips, and a vehicle that rests on the support surface with a plurality of contacts. Heytow’s patent disclosed an arrangement five contacts to ensure a connection regardless of the position or orientation of toy vehicle upon the track support surface.
Heytow disclosed a five-way bridge rectifier as shown to the left in his Figure 5 below.
The slotless electric slot car idea was used in the market in the 1970’s in the Heathkit product shown below.
1975, US patent 3,885,502, Sarno, Daugherty, and Schneidinger, “Entertainment Vehicle Ride”
In this patent the inventors disclose a track support surface of parallel electrodes alternately arranged with alternate polarity, and a vehicle with four contacts to pick up the power. The patent discloses a four-way bridge rectifier.
The above image highlights the four contacts labeled 70, 72, 74, and 76 that form the familiar “tetrahedron” shape used today in the Open Dots standard. This pattern combined with the parallel electrodes of the support surface allow power to be delivered regardless of the orientation or position of the device on the support surface.
The patent discloses that the system is energized with 50V of DC power.
1980, US patent 4,324,301, Jon Eyerly, “Bumper Car Amusement Ride”
This patent discloses a support surface of parallel electrodes energized with alternate polarity and a bumper car with four contacts. The contacts are connected via a four-way bridge rectifier. Three of the contacts are equally spaced to form the vertices of an equilateral triangle, with a fourth contact at the center of the triangle.
Bumper cars employing this technology have been in use for decades.
Some modern bumper cars continue to employ this technology as shown in the below image from 2011.
1996, US Patent 5,868,076, David Myus, “Slotless Electric Track for Vehicles”
This patent discloses a track support surface of parallel electrodes energized with alternate polarity. Four contact points are arranged to form the vertices and center of an equilateral triangle.
A slotless slotcar arcade game was introduced on the market called “Stockcar Showdown”.
Although not recommended, the Stockcar Challenge track can charge an Open Dots enabled iPhone 6. See the below video.
In 2007, conductive wire-free products were introduced into the marketplace using a support surface comprising parallel electrode strips energized with alternate polarity. Four contacts arranged as the vertices and center of an equilateral triangle pick up the power regardless of position or orientation. A four-way bridge rectifier is used to connect the four contacts to the on-board power rail.
When the product was introduced, it was recognized by TIME magazine as one of the best inventions of 2007.
In 2012 Chrysler released the Dodge Dart as the world’s first in-vehicle wireless charging system. The device used a support surface of parallel electrodes energized with alternate polarities that worked with devices using four contact points arranged as the vertices and center of an equilateral triangle. The support surface product was produced by JVIS-USA, LLC, a tier one auto supplier. The product was nominated AOL’s Automotive Technology of the Year at the 2013 Consumer Electronics Show.
In 2015 the Open Dots Alliance was formed publishing an open standard for the technology so that products from various companies would work together.
The technology offers the following advantages:
- Ultimate Safety: Does not employ electromagnetic fields.
- Free positioning: Devices run anywhere on a pad at any orientation.
- High power: Can power devices up to 160 Watts.
- Power Diverse: low and high power devices can run side-by-side.
- High efficiency: The technology can be made nearly 100% efficient.
- Low Cost: Implementation of the technology is inexpensive.