Burroughs Beam-X BX-1000, up and running, counting from 0-5!

[Dekatron42]

Hi all,

 

I've finally had some time to hook up a burroughs Beam-X BX-1000 to a Nixie and some simple astable and monstable multivibrators to have it count. I modified the BX-1000 circuit so that it counts from 0-5, this was done by skipping two steps on each half of the ten counting steps, therefore using only steps 0,1,2,5,8,9 - the Nixie is then hooked up to display 0,1,2,3,4,5.

 

I used an old Burroughs DC-111 counting module that I bought several years ago as non working but a while ago I spotted the problem, one dry joint on a capacitor and one broken resistor on the tube socket. With new components replacing the broken ones it started up as it should. The dry joint did not show until I pulled on the components, I also spotted the broken resistor while pulling at it. They were connected to one spade each so the tube did not work properly as they are needed for the beam to step properly.

 

While I was repairing the DC-111 I decided to modify it so it would count like the tens in a minute counter. The documents available on the Internet described how it could be done but it took me a long time to understand how it was done and why/how it worked, but I finally succeded in modifying it so now I can build a clock in the future. Similar modifications can be done to have the hour counters count in 12 or 24 hour mode, but they will also require a common reset pulse to reset to 00 for the 24 hour clock or to 01 for the 12 hour clock.

 

Here's a very short video showing the current breadboard design: http://www.youtube.com/watch?v=O-JPo_Se10A .

 

/Martin

[threeneurons]

Good work !

5 more, and you have a working clock !

A note on the carbon comp resistors, on those modules. Check each one of them. They can go way out of tolerance, just sitting there, all these years.

[Dekatron42]

Thanks!

 

I only have two of these but I used them to test 40 BX-1000 yesterday and all were working, not at the top rated speed but well enough to be used in a 110KHz counter like the DC-111 module was designed for.

 

Fortunately all components on these two modules were within spec so they ran as they should. The only drawback with these tubes is the spacing that you'll have to put them at and also their sensitivity to magnetic fields, so I'll have to shield the transformers and I'll design a new PCB with all BX-1000's spaced correctly.

 

I just made a new short film showing the other module counting from 0-9, this module has not been modified so it counts in a cycle without any skipped steps: http://www.youtube.com/watch?v=4x8fR1NGFVA .

 

/Martin