Re: [SLUG] spelunkers of the world ...
At risk of teaching how to suck eggs: It's normal to pull something like a solenoid down to ground using an N-channel MOSFET. For logic level gate drive the MOSFET neets to be a logic-level device - something everyday like an IRF-540 won't completely turn on at 5V - you need an IRL- version. I guess in your case it's in a package, and hopefully as such it is logic level! In order to avoid a negative voltage spike from the inductive solenoid, a diode should be reverse-connected across the solenoid. If that wasn't done your MOSFET will be fried. Otherwise, you don't need to have a diode in series, only if you have to guard against reverse connection of your 24 V. Maybe the 24 V is AC? In which case there should be no diodes and the switch is a triac, generally driven by a trigger device, normally an optocoupler. hth Kevin. On Thu, 2011-02-17 at 13:36 +0800, James wrote: Hi My kingdom to anyone who can id the parts U15 and U16 They are marked '44108' 'SA1delta' 'W97k' http://tigger.ws/downloads/img_1329.jpg Why this is not wildly OT: I'm making these POS (Micros 2010) run linux. The CashDraw solonoid takes a diode to +V, the IC to somewhere to control it and a connector to the cash drawer solonoid I think they are transistors, or OC logic gates (high voltage since the drawer is 24V) but I cannot find anything useful. Thanks James -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] Interviews from FOSDEM
Hi Sluggers, The recent FOSDEM has some interesting 'lightning interviews' on their website: http://fosdem.org/2011/interviews Brett. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] spelunkers of the world ...
Did you notice that pins 5,6,7,8 are all soldered together? I think that rules out the chips being triacs, but my searches for 441 and 44108 turned up nothing likely. Nick. -- PGP Key ID = 0x418487E7 http://www.nick-andrew.net/ PGP Key fingerprint = B3ED 6894 8E49 1770 C24A 67E3 6266 6EB9 4184 87E7 -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Ubuntu 10.4 desktop freezes
Replacing drives with smart errors and reinstalling seems to have fixed
things, and the machine boots much faster now.
Thanks all
Ken
On 14/02/11 08:15, Jon and Hannah wrote:
Hi,
Have you:
Run a disk check (fsck?) and checked the SMART status of your drives?
Run a RAM check - using the ful live CD, you can run that for a few hours and
tell you if your RAM is ok.
The above two have given me the same problem in the past.
The current thing giving me that problem is a rubbish graphics card, which I
notice getting to 98degC and has caused the computer to lock up, and the
screen to go blank. It replaced another rubbish grphics card which did the
same thing, but the screen remained visible, just didn't change.
cheers
Jon
On Sat, 12 Feb 2011 10:44:17 pm you wrote:
I have a problem with an Ubuntu 10.4 desktop.
It regularly ends up unresposive, with a blank screen, often after being
left alone for a while, a few hours or overnight. But can happen while
using machine, where it just stops being able to respond to mouse or
keyboard with no recovery.
No response to keyboard or mouse.
[ctl] [alt] [backspace] has no effect.
Only able to recover by hard shutdown.
I initially thought it might be firefox so shut that down when I left
the machine, it still happened.
I removed some backup software that I no longer used incase I had
misconfigured it as at times I got a message on booting that /etc was
full and had a memory of /etc being the default place for creating some
backups. df did not show /etc was full. Still happens.
Reinstalled /, (have separate /home partition), still happens.
Output of dmesg after a restart contains many repeats of below sequence,
as does dmesg command output done at other times.
Is this a clue to something?
Are their other places that I should be looking?
[11017.517434] ata1.00: status: { DRDY DRQ }
[11017.517446] ata1: soft resetting link
[11017.868242] ata1.00: configured for UDMA/100
[11017.868268] ata1: EH complete
[12817.481237] ata1: drained 32768 bytes to clear DRQ.
[12817.516675] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6
frozen
[12817.516681] ata1.00: failed command: SMART
[12817.516689] ata1.00: cmd b0/d1:01:00:4f:c2/00:00:00:00:00/00 tag 0
pio 512 in
[12817.516690] res 58/00:00:00:4f:c2/00:00:00:00:00/00 Emask
0x2 (HSM violation)
[12817.516694] ata1.00: status: { DRDY DRQ }
[12817.516705] ata1: soft resetting link
[12817.864267] ata1.00: configured for UDMA/100
[12817.864297] ata1: EH complete
[14617.476629] ata1: drained 32768 bytes to clear DRQ.
[14617.512669] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6
frozen
[14617.512676] ata1.00: failed command: SMART
[14617.512684] ata1.00: cmd b0/d1:01:00:4f:c2/00:00:00:00:00/00 tag 0
pio 512 in
[14617.512685] res 58/00:00:00:4f:c2/00:00:00:00:00/00 Emask
0x2 (HSM violation)
[14617.512690] ata1.00: status: { DRDY DRQ }
[14617.512700] ata1: soft resetting link
[14617.860228] ata1.00: configured for UDMA/100
[14617.860246] ata1: EH complete
--
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Re: [SLUG] spelunkers of the world ...
On Saturday 19 February 2011 09:00:04 slug-requ...@slug.org.au wrote: At risk of teaching how to suck eggs: It's normal to pull something like a solenoid down to ground using an N-channel MOSFET. For logic level gate drive the MOSFET neets to be a logic-level device - something everyday like an IRF-540 won't completely turn on at 5V - you need an IRL- version. I guess in your case it's in a package, and hopefully as such it is logic level! In order to avoid a negative voltage spike from the inductive solenoid, a diode should be reverse-connected across the solenoid. If that wasn't done your MOSFET will be fried. Otherwise, you don't need to have a diode in series, only if you have to guard against reverse connection of your 24 V. Maybe the 24 V is AC? In which case there should be no diodes and the switch is a triac, generally driven by a trigger device, normally an optocoupler. On Thu, 2011-02-17 at 13:36 +0800, James wrote: Hi My kingdom to anyone who can id the parts U15 and U16 They are marked '44108' 'SA1delta' 'W97k' http://tigger.ws/downloads/img_1329.jpg Why this is not wildly OT: I'm making these POS (Micros 2010) run linux. The CashDraw solonoid takes a diode to +V, the IC to somewhere to control it and a connector to the cash drawer solonoid I think they are transistors, or OC logic gates (high voltage since the drawer is 24V) but I cannot find anything useful. Alas I get to keep my kingdom. but thanks to Nick and to Kevin for research and suggestions. Tracing out the circuit shows that the mysterious part must switch to ground in response to a logic signal, so I'll walk past and not be stumped James -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
