Anode power supply for VFD display ( 5v to 80v stepper PSU )

For my next project (another VFD clock ;), I need a small variable PSU. The main issue with the VFD display, is the power supply. In fact you need 2 differents PSU:

  • a 5v / 100mA for the filament
  • a variable 20 to 75v for anodes..

VFD tube like the IV18 need something like 20/30 volts in direct drive and 50/70 volts where they are muxed. As I can not use them in a direct drive, I need a psu that support output from 20 to 75v, by this way, I can dim the display easily and test the whole stuff in a direct.

I already have done several nixie PSU, but this time I want to build something small (doesn’t cost a lot) with really common parts. I decided to look at smaller mosfet, and I found the BS107 .. small TO92 package and 200v ;)

Here the schematic:

http://jkx.larsen-b.com/photos/VFDProjects/vfd_psu_schm.png

With this simple stuff, and a little microcontroler, you can step the output easily. You can use a 220uH inductor with a 5v VCC, or a smaller one 100uH if you have a PSU between 6v to 15v.

/Enjoy the next step

Related posts :

admin December 26th, 2006


One Response to “Anode power supply for VFD display ( 5v to 80v stepper PSU )”

  1. Jkxon 29 Dec 2006 at 1:39 pm

    The BS170 is another candidate, because the BS107 has a high Ron (~25 Ohm), and the BS170 not. But the BS170 max output is 60v..

Comments RSS

Leave a Reply