Prototypes

PROTOTYPES

We began our prototype building and basic testing on a bread board. The following circuit blocks for the feedback control loop were assembled in accordance with our first inverting topology schematic.

1. 555 Timer block (square wave output voltage)

2. Integrator block (expecting triangle wave output voltage)

3. Original prototype photograph with both blocks above

After quite a few revisions, we obtained our final schematic from our final working simulation. The images below of the second prototype are based on that simulation.

1. Whole feedback control block (555 and comparator)

2. Comparator output pulse (upper wave) obtained using three different feedback voltages and the 555 generated triangle pulse (lower wave)

Vfb=5volts ||| Vfb=6.5volts ||| Vfb=8volts

Notice how the frequency of the square wave stays constant, but the ON time duration of the pulse gets longer as Vfb increases.

3. High current block (switch, output capacitor, diode) and (inductor, paths)