FAQ - NIM - SPECS - HISTORY ongoing and updated

If you have a question about this topic, the answer is probably in here!
User avatar
Richard Hull
Posts: 11427
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Re: FAQ - NIM - SPECS - HISTORY ongoing and updated

Post by Richard Hull » Sun Jan 08, 2006 6:25 pm

6V in a bin is very rare! 6V bus wiring, output test jacks on front, etc. are common. Most 6V was generated by 6V power supply plugins (2 wide) and went onto the bin buss, thus enabling it. LRS (Lecroy Reserach Systems) modules regularly used the + and - 6v bus for their more complicated nim modules as did BNC (Berkley Nuclear Corp.).

For those with +/-6 Volt test pins on the front power panel, but with no +/-6 volts measured, here is the explanation. The 6 volt buss receives it power and transmits it on pins #10 and #11 to all modules. (see the origianl posting in this thread for the pinouts) NIM bins with the test pins have the 6 volt buss wiring. You will need to buy the nim modules that use the 120 volt line voltage into them to generate +/-6volts within them and output these voltages from their pins 10 and 11. Once plugged in and turned on, the +/-6 volt busses are now powered up.

Nim module makers worked almost exclusively in circuit design to avoid using any 6 volt power within their modules. The thinking was that if they did, it would involve extra expense for the purchaser of their module as they would be forced to power their buss with another module.

Why have 6 volts at all? Well, when the first NIM culture developed there were a lot of germanium transistors still in use and power consumption could be kept low by doing a lot of the electronics on a lower voltage buss. Silicon transitor technology was booming and was the future so 12 volt and 24 volt busses were also used in the main buss power. Very quickly the 6 volt buss fell into disuse. By the 1970's IC's, mainly DTL and especially TTL were the norm and the 6 volt buss came back into its own as the 5 volts needed for these systems fit the 6 volt, multiamp buss perfectly.

The upshot is that the earliest Nim modules might be found in need of 6 volts and a few of the last or latest might also need 6 volts. Still, most makers avoid the 6 volt buss like the plague.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

Posts: 1482
Joined: Wed Oct 24, 2001 6:14 pm
Real name:

Re: FAQ - NIM - SPECS - HISTORY ongoing and updated

Post by Starfire » Sun Jan 08, 2006 9:33 pm

Tks Richard - that explains why it was difficult to trace the 6v's in the regulators. Your experience is as always, valued and respected.

Posts: 13
Joined: Wed Sep 23, 2015 7:17 am
Real name: Juan Dosio

Re: FAQ - NIM - SPECS - HISTORY ongoing and updated

Post by JuanDosio » Thu May 26, 2016 5:39 am

Thanks again for a great FAQ ! don't wish to be a bother but would anyone be willing into going into more detail regarding specific nim modules. Would quite enjoy knowing what is of use and what is not.


Post Reply