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The MSD Digital-7 Plus uses a high speed RISC microcontroller to control the ignitionís output while constantly analyzing the various inputs such as supply voltage, trigger signals and rpm. The high speed controller can make extremely quick compensations to the output voltage, multiple spark series, timing and rpm limits while maintaining accurate timing signals to within 1deg and 1% of the rpm limits.
The circuits and controller of the Digital-7 Plus have been thoroughly debounced and isolated to create protection against Electro Magnetic Interference (EMI).
The MSD Digital-7 Plus features a capacitive discharge ignition design. The majority of stock ignition systems are inductive ignitions.
In an inductive ignition, the coil must store and step up the voltage to maximum strength in between each firing. At higher rpm, since there is less time to charge the coil to full capacity, the voltage falls short of reaching maximum energy which results in a loss of power or top end miss.
The MSD Ignition features a capacitor which is quickly charged with 520 - 535 volts and stores it until the ignition is triggered. With the CD design, the voltage sent to the coil is always at full power even at high rpm.
The MSD produces full power multiple sparks for each firing of a plug. The number of multiple sparks that occur decreases as rpm increases, however the spark series always lasts for 20deg of crankshaft rotation. Above 3,300 rpm there is simply not enough ''time'' to fire the spark plug more than once, so there is only one powerful spark.
The MSD Digital-7 Plus has a built in reverse polarity protection circuit. This will protect the ignition in the event of wrong connections. It will also shut off for protection from a surge in power. The ignition will still operate once the surge or polarity is corrected.