Inventors Club Fall 2015

Constructing the cam assembly.

The Fall 2015 session of Inventors Club has begun, and what a start we’ve had.  In both the morning and afternoon groups we spent the first Saturday of the program discussing circuit diagrams and cams.  We talked about how to read a simple circuit diagram, and what some of the most common symbols mean.  This prepared everyone for working with the circuits needed for our big group project.  All that was needed was a conversation about cams.  After talking about what cams are, and various ways they can be used, everyone started making their own cam and switch assembly.  The goal of the project was that everyone has a cam on a motor which presses a switch when it turns.  Then, with the motor running, the switch spends half the time pressed and half the time released, and is connected to two LEDs so that when it goes between pressed and released the circuit alternates between lighting one LED or the other.  After the second Saturday of working on this we were able to put everyone’s LEDs together and watch them all blink in a fun sparkly display. 

Discussing the PWM circuit.

On the second day, the morning group continued working on the cams and switches, but in the afternoon we added a whole new piece.  The afternoon group used a more complicated circuit diagram to build a pulse width modulation (PWM) circuit.  As usual, we of course started with a discussion of PWM and how it can be used to control the speed of a motor.  Some of the mentors even used an oscilloscope to show the students what the electricity from a PWM circuit is doing and how it affects a motor.  The students added their PWM circuits to the cam circuits they already built, and we were able to not only blink the LEDs, but also control the rate of each pair’s blinking.

Now that we’re up to week 3 it’s time to start working on individual projects. The kids will spend the next 4 weeks designing, building, improving, and showing off their own creations. Bakken staff and mentors will help them create with our tools and materials whatever fun things they can imagine. Then, after showing it all off to parents, friends, and museum visitors, the students will take home their inventions.

Learning to use the materials and tools.