25 Jul
2018
25 Jul
'18
1:41 a.m.
Hi,
I need to replace several broken lamps from our HP-2116B front panel. The
old/original ones are CM-345 or OL-345. This makes sense, they are rated
6V 40mA 10000 hours.
BUT:
The maintenance manual says something different and is even wrong and
inconsistent.
HP part number is 2140-0035, description "Lamp, Incadescent, 6.3V, 0.75A"
This can't be true. 92*0.75A would be 400W alone for the front panel
lights...
The manufacturer code is 71744 (Chicago Miniature Lamp Works), mfg part
number 1775. That is indeed a 6.3V lamp, but 0.075A (better!). Problem:
that is a midget _screw_ base lamp, so wrong socket and only rated for
1000h. The panel and switches need a midget flanged base lamp. Who wrote
that manual? Was he drunk? ;-)
Christian
25 Jul
25 Jul
2:24 a.m.
Christian, when I was restoring the HP Computer Museum's 2116A I ordered a
bunch of these 345 bulbs from 1000bulbs.com - but it seems they no longer
stock them.
I did find this listing though which looks current...
https://www.lighting-pros.com/eiko-345-t-1-3-4-midget-flanged-sx6s-case-of-1
0
They are around 0.04A current draw - not 0.75A!
Hope that helps,
David Collins
www.hpmuseum.net
-----Original Message-----
From: cctalk <cctalk-bounces at classiccmp.org> On Behalf Of Christian Corti
via cctalk
Sent: Wednesday, 25 July 2018 6:41 PM
To: cctalk at classiccmp.org
Subject: HP-2116 front panel lamps
Hi,
I need to replace several broken lamps from our HP-2116B front panel. The
old/original ones are CM-345 or OL-345. This makes sense, they are rated 6V
40mA 10000 hours.
BUT:
The maintenance manual says something different and is even wrong and
inconsistent.
HP part number is 2140-0035, description "Lamp, Incadescent, 6.3V, 0.75A"
This can't be true. 92*0.75A would be 400W alone for the front panel
lights...
The manufacturer code is 71744 (Chicago Miniature Lamp Works), mfg part
number 1775. That is indeed a 6.3V lamp, but 0.075A (better!). Problem:
that is a midget _screw_ base lamp, so wrong socket and only rated for
1000h. The panel and switches need a midget flanged base lamp. Who wrote
that manual? Was he drunk? ;-)
Christian
6:47 a.m.
On Wed, 25 Jul 2018, it was written
Christian, when I was restoring the HP Computer
Museum's 2116A I ordered a
bunch of these 345 bulbs from 1000bulbs.com - but it seems they no longer
stock them.
I did find this listing though which looks current...
https://www.lighting-pros.com/eiko-345-t-1-3-4-midget-flanged-sx6s-case-of-1
0
They are around 0.04A current draw - not 0.75A!
Yes, the Installation and Maintenance Manual on bitsavers
(02116-9153_2116B_Vol2_Oct70.pdf) contains several errors.
Interesting enough, my printed copy of this manual from 1968 (that is
completely different from the 1970 one; it only has parts lists and
schematics, the chapters for installation and maintenance are simply not
there) is right: 2140-0035 6.3V 0.04A
In the meantime I've ordered a bunch of JKL 345 from Mouser (60 Ecent/piece)
:-)
Christian
8:21 a.m.
On 2018-Jul-25, at 6:47 AM, Christian Corti via cctalk wrote:
On Wed, 25 Jul 2018, it was written
To mention, they are actually run below-spec in the processor, which of course improves
longevity and reduces the heat next to the plastic front panel.
Christian, when I was restoring the HP Computer
Museum's 2116A I ordered a
bunch of these 345 bulbs from 1000bulbs.com - but it seems they no longer
stock them.
I did find this listing though which looks current...
https://www.lighting-pros.com/eiko-345-t-1-3-4-midget-flanged-sx6s-case-of-1
0
They are around 0.04A current draw - not 0.75A!
Yes, the Installation and Maintenance Manual on bitsavers
(02116-9153_2116B_Vol2_Oct70.pdf) contains several errors.
Interesting enough, my printed copy of this manual from 1968 (that is completely
different from the 1970 one; it only has parts lists and schematics, the chapters for
installation and maintenance are simply not there) is right: 2140-0035 6.3V 0.04A
In the meantime I've ordered a bunch of JKL 345 from Mouser (60 Ecent/piece) From actual measurements in my 2116C the lamps (CM345)
draw:
register-bit positions: ~ 31ma @ 4.1V
inside the push-buttons: ~ 36mA @ 5.4V
compared to the spec: 40mA @ 6V
( I obtained CM345s from Mouser in 2013. "95 in stock", that would have left 83
after my purchase).
9:42 a.m.
It might be worth saving the bases and buying "grain of wheat" lamps to rebuild
the lights. I see ~70ma 6v lamps available. That sounds similar to the original
specification.
Dwight
________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Brent Hilpert via
cctalk <cctalk at classiccmp.org>
Sent: Wednesday, July 25, 2018 8:21:58 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: HP-2116 front panel lamps
On 2018-Jul-25, at 6:47 AM, Christian Corti via cctalk wrote:
On Wed, 25 Jul 2018, it was written
To mention, they are actually run below-spec in the processor, which of course improves
longevity and reduces the heat next to the plastic front panel.
Christian, when I was restoring the HP Computer
Museum's 2116A I ordered a
bunch of these 345 bulbs from 1000bulbs.com - but it seems they no longer
stock them.
I did find this listing though which looks current...
https://www.lighting-pros.com/eiko-345-t-1-3-4-midget-flanged-sx6s-case-of-1
0
They are around 0.04A current draw - not 0.75A!
Yes, the Installation and Maintenance Manual on bitsavers
(02116-9153_2116B_Vol2_Oct70.pdf) contains several errors.
Interesting enough, my printed copy of this manual from 1968 (that is completely
different from the 1970 one; it only has parts lists and schematics, the chapters for
installation and maintenance are simply not there) is right: 2140-0035 6.3V 0.04A
In the meantime I've ordered a bunch of JKL 345 from Mouser (60 Ecent/piece) From actual measurements in my 2116C the lamps (CM345)
draw:
register-bit positions: ~ 31ma @ 4.1V
inside the push-buttons: ~ 36mA @ 5.4V
compared to the spec: 40mA @ 6V
( I obtained CM345s from Mouser in 2013. "95 in stock", that would have left 83
after my purchase).
2342
days inactive
2342
days old
4 comments
4 participants
participants (4)
-
bhilpert＠shaw.ca -
cc＠informatik.uni-stuttgart.de -
davidkcollins2＠gmail.com -
dkelvey＠hotmail.com