CD playes, radios, alarm clocks and microwave ovens often contain VFDs. VFDs recovered from equipment are often mounted on their own circuit boards with driver ICs, but require additional power supplies beyond that used by logic circuits, to power their filaments and grids/anodes.

The fluorescent displays may contain 7 segment numerals, multi-segment alpha-numeric characters, or dot matrix characters as well as other custom symbols. Each element has a phosphor coated surface a glows when appropriately driven by the controller. Basically they are triode vacuum tubes with multiple sets of anode, cathode and grid/screen electrodes, plus a heater/filament to heat the cathode to cause it to emit electrons. Which numeral/character/symbol is selected is controlled by voltage on its grid. The individual anode element within a character is made to glow by applying a voltage to attract the stream of electrons to that anode.

The heater and cathode are electrically the same element which can cause some complication because of the voltage drop from one end of the heater to the other.

As with most multi-character displays the characters are multiplexed to minimise the number of pins needed to drive it, so each character is turned on and off rapidly in succession, to give the illusion of a steady display.

On the sidebar there is a list of VFD modules that I have recovered from various pieces of scrap equipment and the linked pages include pinouts etc.

• https://en.wikipedia.org/wiki/Vacuum_fluorescent_display
• https://hackaday.com/tag/vacuum-fluorescent-display Quick and Dirty Driver Tips for Surplus VFDs
• https://www.instructables.com/id/Arduino-VFD-Display-Clock-Tutorial-A-Guide-To-VFD-/
• https://www.noritake-elec.com/technology/general-technical-information/vfd-operation
• AN-378.pdf, A Novel Process for Vacuum Fluorescent (VF) Display Drivers.
• AN-440.pdf, New CMOS Vacuum Fluorescent Drivers Enable Three Chip System to Provide Intelligent Control of Dot Matrix VF Display. (COPS424C, MM58341, MM58348)
• Re-using VFDs
• Overview of driver ICs for (VFD-)displays

If any referenced page no longer exists, try looking for its URL on http://archive.org.

• Futaba.com
• Futaba-EU
• Futaba.JP
• Futaba-HK

• noritake-elec
• noritake-itron
• itron-ise

• Samsungsdi.co.kr

• newhavendisplay

• Reverse engineering VFD-front panel from deceased Sony BluRay-player

If looking for obsolete modules, try archived versions of the manufacturers website on http://archive.org.