Hillary Doucette

Hillary DoucetteUpdate 3/31/10This week I have continued focusing my efforts on the electrical units. OnWednesday, I received the wireless control circuit. Wednesday night I soldered thecircuit together and hooked it up to the power supply. After some time, I was able to getthe circuit trained to the transmitter and working properly. Thus, when a button on thetransmitter was pushed, a relay caused a 5V signal to be sent out of an output port. Thiscircuit had 4 outputs in all – the outputs corresponded to lift up, lift down, winch up, andwinch down.Thursday afternoon was spent at home depot shopping for more composite wood,electrical connectors, and additional paint. On Friday, I soldered extending wires on allof the electronics. This included extending the length of both the winch and lift motors,the 4 wires from the LED light, the photoelectric sensor, as well as the position switch.Once finished with that task, I assisted Steve in the spray painting of the car sides, as wellas spraying the metal connectors that will be placed on the track. Lastly, I assisted Stevein cutting composite wood for the track’s lift.The PCB arrived from advanced circuits on Monday. Monday night I soldered allpieces to the circuit, as well as began to solder wires onto the board for variousconnections to electronic parts. At the end of the night, I hooked up the PCB to the LEDlights, DC-DC converter, and power supply to test its functionality. By Monday evening,the PCB worked as planned.

Tuesday morning was spent soldering more wires to the PCB’s designated inputoutput ports. These wires were then connected to their corresponding electricalcomponent – wireless circuit control unit, motor control units, position sensor, and liftsensor. Once this was complete, the PCB was hooked up to a power supply again, andwas found to work properly. The last task on Tuesday was to hook up the PBC to the carbattery, and connect the motors to their corresponding motor drivers.After doing so, the PCB worked perfectly, but the motor driver for the winchmotor was slow and continued to stall. In an attempt to troubleshoot, I disconnected themotor drivers from the PCB and tested them on the power supply. They seemed to workproperly alone. I then swapped the motor drivers and hooked them back to the PCB, butthe same problem occurred. However, if I swapped the input signals to the drivers, theproblem for the winch motor dissipated, but the motor driver for the lift motor stoppedworking all together. To find out why this occurred, I detached the drivers again andtested the motor driver that stopped working on the plugged in power supply. After somework, it was apparent that the driver was overloaded with current and no longerfunctioned. Frustrated, I hooked up the remaining motor driver to the winch motor andtried to power it so that the winch would go in a reverse motion. However, a mistake Imade caused the winch to retract, and the second motor driver became overloaded withcurrent as well.After frying both motor control circuits, I wanted to find out if the initial problemwas related to my PCB. Thus, I detached everything but the wireless controls from thePCB and hooked it up to the power supply. When doing so, two wires underneath thePCB touched, and a circuit was shorted. From then on, the wireless controls stopped

working. Finally, to continue with bad luck, as I was cutting the two wires on the bottomof the PCB, I ended up scratching through a copper wire without realizing. As I hookedthe PCB back up, it fried as well.Early Wednesday morning, a new wireless control board was ordered and isexpected to arrive Friday. Also, two new motor drivers and two PCBs were ordered.Everything should arrive by Wednesday, March 6 th .Hours worked:Wednesday: 3Thursday: 1Friday: 3.5Monday: 7.5Tuesday: 15