A project log for Modular Nixie Display

Modular nixie display board based on the soviet Russian IN-12A cold-cathode tubes.

johnnyJohnny 12/17/2015 at 08:053 Comments

I'm trying out the INS-1 indicator bulbs to replace the generic ones I use.

Datasheets are still in Russian, but google translate to the rescue!

DesignatorElectrode Type
1 - The smaller cylinderAnode
2 - The larger cylinderCathode

See the dark dot in the pinout diagram? This matches a dot on the envelope of the indicator (image below). The dot is next to the anode pin. Another way of tell the anode from the cathode, as the table above suggests, is finding the pin that connects to the smaller cylinder.

Parameter NameMinimumMaximum
Firing Voltage, in V6590
Sustaining Voltage, in V-55

Recommended current, providing sufficient brightness is 0.5mA.

Because the sustain voltage is about 55V, I'm using a 180V power supply and 0.5mA is required, about 270K current limiting resistor is used.


Ch Delannoy wrote 03/14/2022 at 16:51 point

hi, thanks for the informations,

I could make the indicator to light, but I have this problem: I needed more than 90V for firing, using a voltage-stabilized power supply and when it starts lighting, it seems to burn; not possible to low down the voltage without lighting off. Do you use a starter (as for neons) or something like this?


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colglover70 wrote 05/25/2019 at 21:29 point

Hi, shouldn't the resistor be nearer 250k?

I've used these tubes and they are pretty good 

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ark20 wrote 10/26/2018 at 16:56 point

Hi!  I love your work so much!

by the way, I'm wondering what wattage size of the resistor is used in the picture

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