FY6900 Signal Generator Power Supply Modifications

The FY6900 Signal Generator in SDG Mailbag #029

In this article, the power supply module for the FY6900 is replaced with a custom-designed PCB with DC-DC converter modules followed by a linear regulator stage for improved noise performance.

The dubious AC-DC SMPSU

The original power supply module incorporated into the FY6900 generator is a generic ultra-low cost design. There are some immediate design aspects that would result in the power supply not passing UK approvals for safety and given that this unit may be powered up for considerable lengths of time, this is something I wanted to address.

SDG #077 – Walk-through of designing the DC-DC converter PCB in Proteus

The YouTube video explores the design of the new power supply PCB which has been implemented in the modified FY6900 signal generator.

The Schematics, Gerbers and Bill of Materials for the double-stack PCB design are attached below.

I cover the build and test of these PCBs in the two YouTube videos linked below. Consider using https://jlcpcb.com/ for your PCBs if you choose to duplicate this design.

The files linked above have been modified to correct the hole spacing in the PCBs

Testing the DC-DC Board
Finishing the PSU modifications