A Note from Digital Delay

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Digital Delay Electronics, Inc.

2036 Fillmore Street Davenport Iowa 52804

Phone 563-324-1046

The Piercing of Rumors Using Facts 2.

There have been rumors about people connecting a number of different input devices, such as an accelerometer or drive shaft counter, to our delay boxes. These alleged practices work with output devices, such as throttle stops or nitrous, to illegally control the vehicles ET. However easy this may sound, there are several reasons why this is not possible to do. Below are only a few of these reasons.

1. The first and main obstacle is the circuit design itself. All of the inputs, including the tach, have RF filters on them that limit a signalís bandwidth that can pass through to the processor. For example, all of the push-button inputs have a designed-in time delay on the press of the button, to eliminate button contact bounce. This delay amount is not a constant, but should fall in the range of .010 to .020 seconds. This means that no input device can send real time data to the processor.

2. Another obstacle is the limitations of the processor. When you view the block diagram of the processor, on page two, it looks covered with I/O (input/output), however only port A is associated with any timers. There are five timers on port A. They are OC1, OC2, OC3, OC4, and OC5. When we design new products, such as the Mega 450, the timers limit how much the unit can do at any one time. To get the most out of the unit, we break up the program into sections. Section one is while the car is staged, before the transbrake releases. During this time the five OC timers are configured as such, OC1 = Tap, OC2 = SLE, OC3 = Tach, OC4 = Crossover time, and OC5 = Delay 2. Section two is while the vehicle is going down the track. During this time the five OC timers are configured as such, OC1 = .01 second timer for playback tach, OC2 = Throttle timer 2, OC3 = Tach, OC4 = throttle timer 1, and OC5 = Shifter. As you can see we had to reconfigure the timers for each section just to get all of the features we could into the unit. While we would like to have added even more outputs, such as a straight RPM switch or a dedicated nitrous output, it was not possible because there are no timers left to perform these or any other operation while going down the track.

3. Another obstacle is all of the outputs of our delay boxes use relays, which are either on or off. To understand how this causes a problem, consider your street carís cruise control. Imagine how poorly it would work, if it only had full throttle or no throttle instead of a continuously variable throttle.

There are many more reasons including processor speed, available memory, and power requirements to name a few that provide insurmountable obstacles in changing the way one of our delay boxes functions. Also Digital Delay always uses one time programmable processors (OTP), which once programmed canít be changed, not even by us. This means that no one can alter the software in one of our processors.

The bottom line is, using one of our delay boxes to control a vehicleís ET is impossible.

Thank you, for taking the time to read this document.

Thank you,
Dwain C. May
President and Head Engineer

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