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Need Help With Finding A Controller Circuit

RayRay1132

New Member
I recently got my hands on 60 mini neon indicator lamps and I plan to arrange them into 4 seven segment displays for a clock that I'm building. Any ideas on a good controller for this?
 

Visitor

Active Member
The 7441 or 74141 TTL nixie tube driver chips popped into my head, but they've gone unobtainium.

This reference may give you some ideas, as the voltage requirements for non bulbs are similar to those of nixie tubes.
 

gophert

Well-Known Member
Most Helpful Member
I recently got my hands on 60 mini neon indicator lamps and I plan to arrange them into 4 seven segment displays for a clock that I'm building. Any ideas on a good controller for this?
a neon will only light one electrode in the neon if you power with DC. Both will illuminate with AC power. 90v AC at a few milliamperes is typical. Do you know the ratings (or model number) of your bulbs?
 

gophert

Well-Known Member
Most Helpful Member
I recently got my hands on 60 mini neon indicator lamps and I plan to arrange them into 4 seven segment displays for a clock that I'm building. Any ideas on a good controller for this?
The few projects I've built with LEDs making each segment of a 7-segment display, I used three LEDs per segment (21 LEDs per digit). So, you'll need to limit to 2 bulbs per segment and it might look a bit odd unless you diffuse the light into a bar shape.
 

Visitor

Active Member
a neon will only light one electrode in the neon if you power with DC. Both will illuminate with AC power. 90v AC at a few milliamperes is typical. Do you know the ratings (or model number) of your bulbs?

Good point about AC vs DC.
 

RayRay1132

New Member
a neon will only light one electrode in the neon if you power with DC. Both will illuminate with AC power. 90v AC at a few milliamperes is typical. Do you know the ratings (or model number) of your bulbs?
I dont know the specifics of the bulbs exactly. However, I had an idea, would it be possible to connect a controller circuit to a whole bunch of relays connected to an ac source, that way instead of powering the bulbs directly from the controller I could power them indirectly from mains voltage with a resistor in between.
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
A reminder with Neon lamps. if you supply them with some voltage x, they will keep their state. You can change the state by briefly raising the voltage or lowering it.
 

gophert

Well-Known Member
Most Helpful Member
I dont know the specifics of the bulbs exactly. However, I had an idea, would it be possible to connect a controller circuit to a whole bunch of relays connected to an ac source, that way instead of powering the bulbs directly from the controller I could power them indirectly from mains voltage with a resistor in between.
Yes, that would work. But multiplexing may be difficult with relays because switching speed is slow so you may need 7 Segments x 4 digits = 28 output pins to make this happen. Also, you'll need 28 transistors or 4 ULN2004 transistor arrays to drive the coils on the relays.
 

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