Week 8

We are back to the conceive and research stage and are looking into commanding the motor speed. We came up with a few possible ways and the week is spent in trying all the possible to see if the arduino commands the motor. Ways includes: digitalWrite, servo library signals and potential meter method.

After that we found that the signals sent by the servo library works best and has a smoother transition compared to the others. Integrating the system together proves to be a challenge again but it was easier to use.

We built a circuit that uses 2 transistors to control whether the solenoid is on or off for the parachute system.

There are two switches that are ganged together. We decided to use 2 slide switched as the ganged switches. When both switches are in the same direction, the circuit is either on or off.

There are 2 battery sources (1 is from the auxillary power to the parahute, the other is from the system main power to the drone). The left 12V is the auxillary power and the right 12V is the main power.

When the circuit detects main power failure, the transistor TIP110 (1) will turn off, and TIP110 (2) will turn on, therefore turning on solenoid, speaker and LED.

When the mercury switch is close circuit, indicating that the drone is plunging or flipping, the transistor TIP110 (1) will turn off, and TIP110 (2) will turn on, therefore turning on solenoid, speaker and LED, regardless whether there is main power failure or not.

During normal flight, the main power is on and the mercury switch is open circuit, the transistor TIP110 (1) will turn on, and TIP110 (2) will turn off, therefore turning off solenoid, speaker and LED.