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AccraSpeed Sports Training Device Q and A’s


1. What does AccraSpeed do?


Accra Speed senses acceleration along its longitudinal axis. When the acceleration force, or “G” level, reaches a pre-settable level, an audible chirp is emitted until the level falls below the set limit. The acceleration can be linear along the axis or the result of rotary motion either along the arc or perpendicular to it (centripetal acceleration).


2. How can this help in sports training?


Virtually all sports involve motion, and motion that changes velocity. Any change in motion is a result of acceleration, either positive or negative. A karate thrust would be linear (sensed either as the thrust or the deceleration at impact, depending on mounting direction); a softball and baseball pitch,tennis stroke or golf swing are rotary. Knowledge of where the maximum acceleration occurs can be gained, the level you achieve can be recorded and used as a baseline for improved performance, the duration of acceleration above a lower preset level can indicate your tempo or follow through distance, a low set predetermined setting can be used to indicate too rapid a backswing in golf or bowling, warm-up settings can help control routines, etc. The applications are too numerous to list, and you can find many ways to adapt it to your performance.


3. How does it work?


The unit operates by utilizing Newton’s law of motion that states a body in motion tends to stay in motion, and a body at rest tends to stay at rest, unless acted upon by an external force. The device contains a spring supported, self battery powered element that is free to slide over a limited distance. Two spring loaded gold plated contact pins complete a circuit by contacting a gold plated ring when they move a short distance in response to a motion induced force, and trigger a chirping sound. The application of an acceleration force causes the element to overcome the main spring force and results in activation of the device.


4. Does the device measure or indicate speed?


The device has 56 indicated settings that provide indications of relative levels of acceleration. It is not intended to indicate specific quantitative acceleration levels, since this knowledge is not very relevant to sports applications. Specific speed readings in sports are useful when the ball or other object is monitored; the objective of Accra Speed is to monitor the athlete’s characteristics that propel the object, not the resulting speed. Remember that linear speed is the result of acceleration and time, and centripetal force is a function of rotary speed. Accra Speed is a viable tool for monitoring sports performance that results in improved athletic accomplishment. In short, speed is not measured directly.


5. Can you give some specific examples?


In softball and baseball users can use pre-determined settings to limit arm velocity during warm up, use low settings as an audible tempo reminder for catcher or infielder throws where rapidity is important, for batting swing monitoring to perfect follow through and swing speed, for pitcher arm speed velocity for change-ups to enhance batter deception, etc. With the device wrist mounted, you can verify that your fastball and change-up are thrown at the same wrist speed to deceive the batter, while the ball speed is varied by hand input.


Possible tennis applications are for a tennis service stroke warm-up, where a pre determined pattern of stroke settings is used to help work up to a full level. The full level setting is then used as a reference for performance enhancement. The duration of acceleration level is discernable by the player, and can be used to control over swinging. For ground strokes, both tempo and proper follow through can be monitored by using a low, predetermined setting. The player can monitor his swing easily.


For golf, a very low setting can be used for keeping your backswing speed below a desired level. Higher settings are useful for finding the point of reaching a predetermined radial centripetal acceleration (velocity), the duration of that level or the achievement of a higher level. This information can be translated into distances for wedges during practice sessions or for numerous other purposes. Lower settings can also be used as an audible reminder for swing tempo. Remember, the measurement is at the device’s location, not at the ball. For distance control, the golfer develops a swing velocity of his hands that when combined with club response results in a ball velocity. AccraSpeed provides the ability to develop proper swings for specific distances.


For bowling, the unit can be set to trigger at a pre-determined arm rotation speed for either swing direction, or as a follow through monitor.


There are numerous applications for other sports as well.


6. How does gravity affect AccraSpeed?


When held in a horizontal position, gravity does not affect the device. When it is turned to a vertical position with the adjustment end up, there is a negative 1“G” effect on the unit, and with the adjustment end down a +1”G” effect is applied. By adjusting the device to just trigger when held adjustment end down, then rotating it to the horizontal position, the output should stop as the effect of gravity is eliminated. This effect is a function of our earth’s environment, and it applies to all of our activities. For sports activities, AccraSpeed is used to measure relative acceleration levels, and the gravitational influence is at such a relatively low level that it is not detrimental to its uses.


7. How should AccraSpeed be stored?


AccraSpeed does not require a separate on/off switch. Whenever AccraSpeed is between uses the adjustment should be set to a level of three (3) or higher to prevent accidental triggering. If being stored for an extended period (a few months or more), the battery should be removed and stored separately.


8. What should I do if the unit stops functioning or becomes erratic?


Remove the adjustment end, hold the battery case and lightly tighten the slotted end cap to guarantee proper battery contact. Verify there is no debris or water in the case. If after reassembly the unit still malfunctions, try removing the battery and either test it or replace it.


9. How long should the battery last?


The power consumption is very low under normal usage, the battery is quite robust and should last for several months or years.