Bowling Game

This circuit is used to sense the insertion of a penny. Before the penny is inserted, current is flowing through the detector (transistor) side of the optointerruptor, and Port M5 is HI. When the penny blocks the optointerruptor, Port M5 goes low. The hex inverter with Schmitt trigger (74HC14) ensures a clean digital signal from 0 to 5 V. The typi
Bowling Game - schematic

cal positive going threshold for the 74HC14 is 2. 38 V, while the negative going threshold is 1. 40 V. This simple switch circuit outputs high when the switch is pressed and low when the switch is not pressed. The resistance value was chosen so that the current through the switch wasnot too high. The maximum current is approximately 18. 5 mA, which is within the limits of the switch. This circuit is used as an analog input to the A/D controller in the C32. It is used to select the difficulty level of the game. A large total resistance was chosen because the potentiometer is only being used as a voltage reference, so it does not need to source or sink much current. A voltage divider was tied to the high side of the potentiometer because the A/D port of the C32 only accurately read voltage values up to about 2 V. This circuit is used to activate the solenoid. When Port AD5 is high, current runs through the solenoid and it is activated. The IRLZ34N was chosen as the transistor because it is able to tolerate a maximum drain-to-source voltage of 55 V, and up to 30 A of current. The resistance of the solenoid is 2 ©, the internal resistance of the IRLZ34N is 0. 035 ©, and the power resistor is 10 ©, so the current through the solenoid is 1. 08 A. The buzzer is activated when Port AD6 is high. The 2N7000 MOSFET is used because the current in this circuit is not too high (the resistance of the buzzer is 250 K). To activate the...

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