5V to 9V Boost Converter
Sample Individual Project
Here's an example of an individual project for this course:
It is a 5V to 9V boost converter. It takes in an input voltage of 4.5V-6V and outputs 9V for driving a camera. The boost converter was part of a walker, it was used to convert 6V (4 AA batteries) up to 9V to drive a wireless camera. Four (x4) AA batteries were chosen instead of a single (x1) battery since AA batteries could supply charges longer than 9V could. Instead of wasting power in converting 9V to 5V to power the rest of the walker, it was chosen to upscale the voltage to 9V just for the camera and use 6V for the rest of the peripheries and motors of the walker (this solution was found to be more efficient and the batteries lasted longer).
The converter was built using through hole components. The though hole components were soldered on a perf board (instead of just using a bread-board) for mechanical rigidity, stability, and support of the circuit.
An example measurement of the walker is shown below:
The schematic of the 5V-9V boost converter is shown below:
The boost converter uses 3-main circuits, it takes advantage of the backward EMF of an inductor when its magnetic field is cut abruptly. To charge and discharge the magnetic field of the inductor, an oscillator (generated by the 555 timer) is used in conjunction with an NPN (2N3904) transistor (that acts as the switch) to open and close the flow of current to the inductor. A diode is used to rectify the switching circuit. A large bank cap (100 uF) is used to store and capture the large voltages generated by the collapsing EM fields. A regulator (7809) is then used to regulate, and smooth the output voltage to 9V. A 1k resistor is put at the output in addition with the load (as a safety measure) in the event if there is no load, no sparks fly across the large capacitor (100 uF) and that the capacitor has a pathway to safely discharge itself once the circuit is no longer being used and is off.
A sample design report of the above 5V-9V boost converter with full detail on how it operates can be found below:
*** Design report, schematic and all material related on this website to the boost converter is subject to copyright © by Shakeeb Abdullah and may not be changed, used or altered in any way shape or means, whether physically, or digitally (electronically) without prior permission of the author. Free for distribution for educational or non-profit purposes.