I lit up the IV-27M, which I bartered with a retro display tube enthusiast in Ukraine. For more information about the VDF I bartered with, please see here.
The IV-27M is a 13-digit VFD. It has 14 digits when you add the digits for minus and overflow indications.
It is very nice that the tube is transparent and the back side is transparent. I would like to make this VFD shine.
Pins of the heater
IV-27M has pins on both sides of the tube. I checked with a tester and found that pins 4 and 5 on the right side are the heater.
Voltage of the heater
Here is a translation of the IV-27M datasheet in Russian using Google Camera. We found out that the filament voltage is about 3V and the filament current is about 180mA.
Also, the anode voltage seems to be 24V.
When the voltage was increased with the stabilized power supply DPS605U, the current flowed 150mA when the heater voltage was set to 3.3V. The heater can be driven by the same voltage as the microcontroller, 3.3V.
Connect all the wires except the heater to 24V, and turn on the power.
It lights up!
The left side is brighter and the right side is dimmer because the heater is not driven by AC, but all the segments are lit.
It is very beautiful.
It's beautiful that it's transparent and you can see through the back. It is not dynamically lit, so it is quite bright. The orange light of the Nixie tube is nice, but the blue-green of the VFD is also a beautiful color.
Next time, I would like to try to display numbers with ESP32.