-- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
Only 4000 resistor P/Ns? I just checked or schematic entry system. There are 104 part numbers for 1K resistors, 24 for 0402s alone. :-(
Are there actually 24 different 1K 0402's?
-- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
Or do they add new numbers without checking existing stock? Different stock numbers from different vendors?
Yep. Every one has a different vendor part number. Something like a third of them (I'd have to count) are from one vendor (Panasonic). I checked for that. The system requires a 1:1 mapping (more insanity) so I really didn't need to check.
The system forces a 1:1 vendorinternal part number, so there are no duplicates in the list.
Absolutely. It's nuts but that's the way the business works. Can't change vendors (or part number within vendor) of *any* part without a complete requalification. Fortunately, that's not my job (would piss me off royally).
As screwed up as the Microdyne system was, it allowed for second sourcing for most parts without a lot of paperwork. Basicly, get samples, send them to engineering and one of the ETs would qualify them. More complex parts would be stuffed on one roduction board for additional testing like when Motorola dropped a support chip for the
68340 and we had to switch to Hitachi as it was the only second source.
Yikes. We have a Highland part number (7-digit telephone number sort of thing) that goes on BOMs. It has a bin in the stockroom and a database entry. In the database is a list of qualified manufacturers or distributors and their part numbers. There's also a link to a folder that has data sheets, notes, test data, photos, web links, whatever.
I checked: we have 40 different 1K resistors, including surfmount, axial, power, pots, and networks. But they are all different.
We do NOT stock a 1K 0402!
-- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
I have reels of 1K in 0603 (20,000 Susumi .1%) & 2512 (3322, Vishay
1%). Probably a few more reels on hand. I still have about 150 reels to sort & inventory.
Thanks! Gotta get me some of those..
Best regards, Spehro Pefhany
-- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
At my last job the system was much more sane (actually, quite good - engineering was allowed to design most of it). Simple parts like resistors could be substituted, parameter for parameter, without engineering intervention. Capacitors could have a tick-mark checked in the control system so that engineering had to be involved for any substitution, or not. Production control couldn't be trusted with things like dielectric type so if it mattered, the box got checked.
Here, there are no substitutions allowed. There are also Asian parts in the system which aren't readily available here. It's a bloody mess. Fortunately, I just have to figure out how to get around the system to get my stuff done.
That's the way it should be (though I don't like your phone number system). We've gone over this territory before, though.
We have that. Supposedly. The truth is that since there is a forced
1:1 mapping between part numbers, if someone in another division has already used the part, we have to use the same part number but none of that information will be in our databases.
Amazing. I probably use ten times as many of each 100ohm, 1K, and 10K resistors as all others combined. All 0402s. Some others I use 0603s because they're easier to change and solder wires to. Yeah, there are a few 1206s where I need power but they're usually really low resistance (shunts or jumpers).
No way to retire useless stock numbers?
Short answer, no. No part numbers are ever retired, even from the schematic capture system. Can't be done. ...and it gets worse from there.
Longer answer, in this case it wouldn't matter. The Asian parts are useful parts, just terribly useful for us. Since we share the databases (a whole 'nother rant) their parts show up in our databases (and ours, theirs, I'm sure). With most parts this doesn't matter (ICs are ICs and resistors are resistors). Primarily the problem is capacitors. They JIS tempcos, rather than EIA. Discrete part number availability is somewhat different, too.
We were able to flag items as obsolete, and they became a reference only. We were looking into a new inventory system, but the fool in charge of engineering wanted to use a three digit part number for resistors and capacitors, with a preceding letter. He insisted that a resistor was a resistor, and a capacitor is a capacitor. Then he hired a woman with degree in Philosophy as our component engineer. She didn't even know what a databook was for. neither were there, very long.
My thought on the system was to create possible numbers for an entire series, and make them active as needed. That way everything would stay in a logical order.
Sounds like a fun place to work. AIUI, one components engineer wanted to straighten things out and got fired for his efforts. Hey, if they want me to take a day to find a useful diode, fine.
Exactly. Encode the value in the P/N so it can easily be read. Leading and trailing digits can describe the type and series. These digits don't have to have any direct meaning (a 'C' for capacitor, or 'D' for diode, would be nice). We do some of that, but it's the vendor part number that's buried in the P/N, sometimes.
At the PPoE they had a system like that, except some bright database programmer decided that sequential part numbers were somehow better so they changed in the middle. Idiot.
Try
FYI, partial reels...
Cheers
Programmers should have psych testing done before they are allowed to write each new program.
Nothing narrow enough. :(
Thanks, and I see that it's a Veteran owned business.
Transformer tape.
Just one source:
Some places will custom slit tapes to whatever width you specify. But you'd have to buy like $200 worth.
They might have it OTS tho in single rolls.
Mil and industrial surplus stores sometimes have transformer tapes. A quarter inch std width would work on tape and reel no problem. Used to use it that way.
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