Odd 7-segment display

Incandescent wires? RCA called them Numitrons.

Search for: IEE FFD21

Once upon a time there were incandescent 7-seg annunciator devices, under various names. Minitron and RCA's Numitron are two names, but do a google search on "incandescent" and "7-segment" for heaps of background.

Thanks.

No replacements available.

So, since this uses the MC14511 driver, which was designed for LED 7-segment displays, all I have to do is provide resistors to each element and rewire for a common-cathode LED display, right?

Thanks,

Does it heat up? Voltages?

When I was young and enthusiastic, I built a frequency counter that used these. I think it was a Practical Wireless design. It's still around somewhere ...

Arfa

Sounds like a Numitron incandescent filament display. These are getting very hard to come by.

James Sweet sez:

Purchasing LED 7-segment replacements and associated kit (resistors, etc.) tomorrow to convert to a 21st century technology.

A little clarification, please...

I'm all ready to start looking for a CC display, when I look at the data sheet for MC14511BCP and it has example circuit hookups for both CC and CA.

I thought a driver output was for one or the other "gender", either CC or CA.

Am I reading this right? Can I use either without further need of other configuration or circuitry? Seems too good to be true...

Thanks, Dave

The data sheet is here:

Due to bug in the data base, the previous link pointed to MC14512...

Thanks,

A second reading of the ds shows that, indeed, a transistor is needed to use a CA display with the MC14511.

I would do happier with you if you stopped changing thread titles.

Sorry, I didn't know this caused a break in thread. My reader simply inserts the re-titled post in the same thread, just with another title. I should have realized that not all reader apps behave the same.

Sincere apologies. Will avoid temptation in future.

Most readers use the message ID and work correctly.

I appreciate it. It is not so much a problem with broken threads, for me, as much as it is that I remember the thread title of threads I have been reading. When you change the thread title, I have to go back and review earlier messages to remember what subject we are talking about.

They used to be popular in petrol pumps in the UK (they are readable in quite bright sunlight).

single-digit

drivers on

available?

Ahh, yes, -when I was about 14 years old I built a digital clock out of TTL devices from a Popular Electronics plan, which would have featured Numitrons as the display elements. I made what must have been the ugliest printed circuit board ever - my school class used the Mactac and hobby knife approach for making PCBs, which gave incredibly crude results. Sadly, my troubleshooting skills were not up to overcoming my crude construction technique and I never got the darn thing to work - it wasn't until years later I found out the key difference between the 7447 display driver and the 7448 that the fellow at the electronics wholesaler sold me.

I may still have the Numitrons sitting in the basement somewhere..

Bill