Week 8-Assignment : Power improvement

1.Electrophoresis variabie power supply

The electrophoresis power supply includes the following components:

1.1 Power supply PCB

1.2 PCB components

The fundamental components of the design are the MAX1771DC-DC controller (12), a MOSFET switch (9), an inductor (1), a

diode (13) and an output capacitor (19).

1.3 Controller control principle

In the design the controller regulates the output voltage via a Pulse-Frequency Modulated (PFM) signal applied to the gate

of the MOSFET. When this signal is high the MOSFET switch is turned on and when this signal is low the MOSFET is turned off. The controller adjusts the pulse rate of the PFM signal, based on feedback from the output,in order to maintain a constant output voltage.

2.Power improvement result:

After testing the electrophoresis power supply PCB(Printed Circuit Board ) can change an external 15V wall-wart power supply to an adjustable 15-100V output.