Re: [time-nuts] HP105B HP 105B 1 amp fuse blowing
On Fri, Oct 11, 2019 at 10:00 PM Dana Whitlow wrote: > > I once read that Supercapacitors come up short in handling really short > spikes, > and that this is not due to physical inductance arising from the > structure. Rather, > the issue was of a subtle (to me) electrochemical nature. > > Can anyone either confirm or refute this? Inquiring minds want to know. > > Dana > Granted the usage is different, but some time ago most HPE/Dell RAID controllers moved from using battery (usually NiCad) backed cache modules, to using flash backed cache with a supercapacitor to power the transfer from cache to flash. One would hope that as these are used to protect data integrity, that HPE and Dell did their homework. I certainly have appreciated no longer having to replace failed battery packs in servers (-: Cheers Arne ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] HP105B HP 105B 1 amp fuse blowing
I once read that Supercapacitors come up short in handling really short spikes, and that this is not due to physical inductance arising from the structure. Rather, the issue was of a subtle (to me) electrochemical nature. Can anyone either confirm or refute this? Inquiring minds want to know. Dana On Fri, Oct 11, 2019 at 2:01 PM Bob kb8tq wrote: > Hi > > Indeed, the unit seems to work fine without batteries. > > --- > > If filtering and short duration spikes are the concern, one could > replace the batteries with super capacitors. One would *hope* they > are a bit less likely to create problems. …… > > - > > While it is a good idea to keep OCXO’s on power, a half hour or > couple hour outage is not that big a deal. They will settle back down > pretty fast after that sort of interruption. Unless the rest of the lab is > on backup power, there may not be a major need for the 105 to stay > up and running …. > > Bob > > > On Oct 11, 2019, at 11:59 AM, Jeremy Nichols wrote: > > > > The 105A was built without a battery. The 105B has a battery and charger. > > > > I have a 105B that had the failed battery removed before I bought it. It > > works fine. I have it on a UPS; it survived our just-finished NorCal > power > > shutdown just fine. > > > > Jeremy > > > > > > On Fri, Oct 11, 2019 at 7:01 AM Scott McGrath > wrote: > > > >> As one who owns a 105 i had the battery properly rebuilt and basically > >> have it on low rate charge and periodically discharge the battery > >> > >> When rebuilding a 105 battery it’s important to replicate its > >> characteristics > >> > >> Remember HP also intended I believe that the battery would also serve > as a > >> filter for the power supply. As I dont recall any version of the 105 > >> without a battery. > >> > >> > >> > >> On Oct 10, 2019, at 4:50 PM, Taka Kamiya via time-nuts < > >> time-nuts@lists.febo.com> wrote: > >> > >> The fact that 25V supply is dropping to 23.4V shows it is drawing far > more > >> current than it is rated. I am assuming this is a regulated power > supply. > >> Does the power brick actually shuts down at 500mA or does it let the the > >> voltage drop and try to supply what it can? Maybe one or more Nicad > has an > >> internal short? That will cause and over-voltage situation per battery > and > >> thus over-current. I've recently seen a brick power supply go into > >> oscillation and produce 3x rated voltage when too much current was > drawn. > >> (and blew the circuit) > >> > >> Also, different batteries has different charging rates. As far as 105B > >> document goes, it says 24V 0.5Amp supply but that is for default > >> configuration. Designed charge rate is 390mA (page 3-4) and is current > >> controlled by A5Q3. > >> > >> I would actually measure how much current is drawn there. Since the > fuse > >> is already blown, just put an am-meter across the fuse and see > >> > >> --- > >> (Mr.) Taka Kamiya > >> KB4EMF / ex JF2DKG > >> > >> > >> On Thursday, October 10, 2019, 4:00:41 PM EDT, Roy Thistle < > >> roy.this...@mail.utoronto.ca> wrote: > >> > >> Hi All: > >> A 105B (quartz oscillator) is blowing the 1A fuse, after it is on about > 1 > >> hour. > >> The fuse appears to have just melted (not a black mark as the result of > a > >> flash, in the case of a high current short.)… just looks like the fuse > wire > >> (inside the glass capsule) melted into some little blobs, for about 1/4 > >> the fuse length, near the middle. It wasn't a fast-blo or slow-blo > fuse... > >> just the normal kind. > >> I think the unit is drawing just a little too much current, as the > result > >> of the batteries needing charging (I had the fast charge option on when > the > >> fuse blew.) And so, the fuse heated up, and finally melted. Not sure why > >> the batteries were not charging normally... but 20.1 volts is what I > >> measured across the pack, initially, and 23.4 V after about 45 min of > >> charging. > >> I am charging the batters, from a power cube, at 510 ma, and dropping > >> (cube gives 25V, 500mA max)… the batteries are 20 C size NiCads, wired > in > >> series... that of course is a retrofit. > >> I don't want to put another fuse in, and blow that too, without some > >> reasonable explanation of why the first one failed! > >> Please, any comments, or hints/suggestions... much appreciated. > >> ___ > >> time-nuts mailing list -- time-nuts@lists.febo.com > >> To unsubscribe, go to > >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > >> and follow the instructions there. > >> ___ > >> time-nuts mailing list -- time-nuts@lists.febo.com > >> To unsubscribe, go to > >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > >> and follow the instructions there. > >> > >> ___ > >> time-nuts mailing list -- time-nuts@lists.febo.com > >> To
Re: [time-nuts] HP105B HP 105B 1 amp fuse blowing
Hi Indeed, the unit seems to work fine without batteries. --- If filtering and short duration spikes are the concern, one could replace the batteries with super capacitors. One would *hope* they are a bit less likely to create problems. …… - While it is a good idea to keep OCXO’s on power, a half hour or couple hour outage is not that big a deal. They will settle back down pretty fast after that sort of interruption. Unless the rest of the lab is on backup power, there may not be a major need for the 105 to stay up and running …. Bob > On Oct 11, 2019, at 11:59 AM, Jeremy Nichols wrote: > > The 105A was built without a battery. The 105B has a battery and charger. > > I have a 105B that had the failed battery removed before I bought it. It > works fine. I have it on a UPS; it survived our just-finished NorCal power > shutdown just fine. > > Jeremy > > > On Fri, Oct 11, 2019 at 7:01 AM Scott McGrath wrote: > >> As one who owns a 105 i had the battery properly rebuilt and basically >> have it on low rate charge and periodically discharge the battery >> >> When rebuilding a 105 battery it’s important to replicate its >> characteristics >> >> Remember HP also intended I believe that the battery would also serve as a >> filter for the power supply. As I dont recall any version of the 105 >> without a battery. >> >> >> >> On Oct 10, 2019, at 4:50 PM, Taka Kamiya via time-nuts < >> time-nuts@lists.febo.com> wrote: >> >> The fact that 25V supply is dropping to 23.4V shows it is drawing far more >> current than it is rated. I am assuming this is a regulated power supply. >> Does the power brick actually shuts down at 500mA or does it let the the >> voltage drop and try to supply what it can? Maybe one or more Nicad has an >> internal short? That will cause and over-voltage situation per battery and >> thus over-current. I've recently seen a brick power supply go into >> oscillation and produce 3x rated voltage when too much current was drawn. >> (and blew the circuit) >> >> Also, different batteries has different charging rates. As far as 105B >> document goes, it says 24V 0.5Amp supply but that is for default >> configuration. Designed charge rate is 390mA (page 3-4) and is current >> controlled by A5Q3. >> >> I would actually measure how much current is drawn there. Since the fuse >> is already blown, just put an am-meter across the fuse and see >> >> --- >> (Mr.) Taka Kamiya >> KB4EMF / ex JF2DKG >> >> >> On Thursday, October 10, 2019, 4:00:41 PM EDT, Roy Thistle < >> roy.this...@mail.utoronto.ca> wrote: >> >> Hi All: >> A 105B (quartz oscillator) is blowing the 1A fuse, after it is on about 1 >> hour. >> The fuse appears to have just melted (not a black mark as the result of a >> flash, in the case of a high current short.)… just looks like the fuse wire >> (inside the glass capsule) melted into some little blobs, for about 1/4 >> the fuse length, near the middle. It wasn't a fast-blo or slow-blo fuse... >> just the normal kind. >> I think the unit is drawing just a little too much current, as the result >> of the batteries needing charging (I had the fast charge option on when the >> fuse blew.) And so, the fuse heated up, and finally melted. Not sure why >> the batteries were not charging normally... but 20.1 volts is what I >> measured across the pack, initially, and 23.4 V after about 45 min of >> charging. >> I am charging the batters, from a power cube, at 510 ma, and dropping >> (cube gives 25V, 500mA max)… the batteries are 20 C size NiCads, wired in >> series... that of course is a retrofit. >> I don't want to put another fuse in, and blow that too, without some >> reasonable explanation of why the first one failed! >> Please, any comments, or hints/suggestions... much appreciated. >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > -- > Jeremy Nichols > Sent from my iPad 6. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to
Re: [time-nuts] HP105B HP 105B 1 amp fuse blowing
The 105A was built without a battery. The 105B has a battery and charger. I have a 105B that had the failed battery removed before I bought it. It works fine. I have it on a UPS; it survived our just-finished NorCal power shutdown just fine. Jeremy On Fri, Oct 11, 2019 at 7:01 AM Scott McGrath wrote: > As one who owns a 105 i had the battery properly rebuilt and basically > have it on low rate charge and periodically discharge the battery > > When rebuilding a 105 battery it’s important to replicate its > characteristics > > Remember HP also intended I believe that the battery would also serve as a > filter for the power supply. As I dont recall any version of the 105 > without a battery. > > > > On Oct 10, 2019, at 4:50 PM, Taka Kamiya via time-nuts < > time-nuts@lists.febo.com> wrote: > > The fact that 25V supply is dropping to 23.4V shows it is drawing far more > current than it is rated. I am assuming this is a regulated power supply. > Does the power brick actually shuts down at 500mA or does it let the the > voltage drop and try to supply what it can? Maybe one or more Nicad has an > internal short? That will cause and over-voltage situation per battery and > thus over-current. I've recently seen a brick power supply go into > oscillation and produce 3x rated voltage when too much current was drawn. > (and blew the circuit) > > Also, different batteries has different charging rates. As far as 105B > document goes, it says 24V 0.5Amp supply but that is for default > configuration. Designed charge rate is 390mA (page 3-4) and is current > controlled by A5Q3. > > I would actually measure how much current is drawn there. Since the fuse > is already blown, just put an am-meter across the fuse and see > > --- > (Mr.) Taka Kamiya > KB4EMF / ex JF2DKG > > >On Thursday, October 10, 2019, 4:00:41 PM EDT, Roy Thistle < > roy.this...@mail.utoronto.ca> wrote: > > Hi All: > A 105B (quartz oscillator) is blowing the 1A fuse, after it is on about 1 > hour. > The fuse appears to have just melted (not a black mark as the result of a > flash, in the case of a high current short.)… just looks like the fuse wire > (inside the glass capsule) melted into some little blobs, for about 1/4 > the fuse length, near the middle. It wasn't a fast-blo or slow-blo fuse... > just the normal kind. > I think the unit is drawing just a little too much current, as the result > of the batteries needing charging (I had the fast charge option on when the > fuse blew.) And so, the fuse heated up, and finally melted. Not sure why > the batteries were not charging normally... but 20.1 volts is what I > measured across the pack, initially, and 23.4 V after about 45 min of > charging. > I am charging the batters, from a power cube, at 510 ma, and dropping > (cube gives 25V, 500mA max)… the batteries are 20 C size NiCads, wired in > series... that of course is a retrofit. > I don't want to put another fuse in, and blow that too, without some > reasonable explanation of why the first one failed! > Please, any comments, or hints/suggestions... much appreciated. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > -- Jeremy Nichols Sent from my iPad 6. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] HP105B HP 105B 1 amp fuse blowing
As one who owns a 105 i had the battery properly rebuilt and basically have it on low rate charge and periodically discharge the battery When rebuilding a 105 battery it’s important to replicate its characteristics Remember HP also intended I believe that the battery would also serve as a filter for the power supply. As I dont recall any version of the 105 without a battery. On Oct 10, 2019, at 4:50 PM, Taka Kamiya via time-nuts wrote: The fact that 25V supply is dropping to 23.4V shows it is drawing far more current than it is rated. I am assuming this is a regulated power supply. Does the power brick actually shuts down at 500mA or does it let the the voltage drop and try to supply what it can? Maybe one or more Nicad has an internal short? That will cause and over-voltage situation per battery and thus over-current. I've recently seen a brick power supply go into oscillation and produce 3x rated voltage when too much current was drawn. (and blew the circuit) Also, different batteries has different charging rates. As far as 105B document goes, it says 24V 0.5Amp supply but that is for default configuration. Designed charge rate is 390mA (page 3-4) and is current controlled by A5Q3. I would actually measure how much current is drawn there. Since the fuse is already blown, just put an am-meter across the fuse and see --- (Mr.) Taka Kamiya KB4EMF / ex JF2DKG On Thursday, October 10, 2019, 4:00:41 PM EDT, Roy Thistle wrote: Hi All: A 105B (quartz oscillator) is blowing the 1A fuse, after it is on about 1 hour. The fuse appears to have just melted (not a black mark as the result of a flash, in the case of a high current short.)… just looks like the fuse wire (inside the glass capsule) melted into some little blobs, for about 1/4 the fuse length, near the middle. It wasn't a fast-blo or slow-blo fuse... just the normal kind. I think the unit is drawing just a little too much current, as the result of the batteries needing charging (I had the fast charge option on when the fuse blew.) And so, the fuse heated up, and finally melted. Not sure why the batteries were not charging normally... but 20.1 volts is what I measured across the pack, initially, and 23.4 V after about 45 min of charging. I am charging the batters, from a power cube, at 510 ma, and dropping (cube gives 25V, 500mA max)… the batteries are 20 C size NiCads, wired in series... that of course is a retrofit. I don't want to put another fuse in, and blow that too, without some reasonable explanation of why the first one failed! Please, any comments, or hints/suggestions... much appreciated. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] HP105B HP 105B 1 amp fuse blowing
I'd take Taka's suggestions regarding the actual battery and charger characteristics. A gross over-current means something's wrong, but a random fuse blowout after many years shouldn't be too surprising either, presuming everything seems normal otherwise. If it's not a battery/charger issue, one thing I can think of is one or more shorted turns in the oven heater winding. This would still allow for heating, but maybe takes too much current while getting to the setpoint. A little bigger fuse may get it past such a marginal condition, and once the setpoint is attained, the average current should drop to a safe zone. This is one of the common failure modes I've seen in device heating ovens - another being burned open, which is worse. Another deal killer is if the heater winding shorts through its insulation to the oven case, whether all the time, or only when it gets hot - that pretty much ruins it. I have an HP740A reference diode oven like that. If the fuse clearing always happens after a certain time range, then a simple check is to keep upping the fuse to maybe no more than twice the proper rating, and try to monitor what's going on, hopefully catching it at the right moment. If it's not battery/charger/heater element resistance-related, then you may have a dreaded heater to case short, which changes everything. In this case, as with an open, you can get try to put some other sort of heating system around it all, but it won't be quite the same. Ed ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] HP105B HP 105B 1 amp fuse blowing
The fact that 25V supply is dropping to 23.4V shows it is drawing far more current than it is rated. I am assuming this is a regulated power supply. Does the power brick actually shuts down at 500mA or does it let the the voltage drop and try to supply what it can? Maybe one or more Nicad has an internal short? That will cause and over-voltage situation per battery and thus over-current. I've recently seen a brick power supply go into oscillation and produce 3x rated voltage when too much current was drawn. (and blew the circuit) Also, different batteries has different charging rates. As far as 105B document goes, it says 24V 0.5Amp supply but that is for default configuration. Designed charge rate is 390mA (page 3-4) and is current controlled by A5Q3. I would actually measure how much current is drawn there. Since the fuse is already blown, just put an am-meter across the fuse and see --- (Mr.) Taka Kamiya KB4EMF / ex JF2DKG On Thursday, October 10, 2019, 4:00:41 PM EDT, Roy Thistle wrote: Hi All: A 105B (quartz oscillator) is blowing the 1A fuse, after it is on about 1 hour. The fuse appears to have just melted (not a black mark as the result of a flash, in the case of a high current short.)… just looks like the fuse wire (inside the glass capsule) melted into some little blobs, for about 1/4 the fuse length, near the middle. It wasn't a fast-blo or slow-blo fuse... just the normal kind. I think the unit is drawing just a little too much current, as the result of the batteries needing charging (I had the fast charge option on when the fuse blew.) And so, the fuse heated up, and finally melted. Not sure why the batteries were not charging normally... but 20.1 volts is what I measured across the pack, initially, and 23.4 V after about 45 min of charging. I am charging the batters, from a power cube, at 510 ma, and dropping (cube gives 25V, 500mA max)… the batteries are 20 C size NiCads, wired in series... that of course is a retrofit. I don't want to put another fuse in, and blow that too, without some reasonable explanation of why the first one failed! Please, any comments, or hints/suggestions... much appreciated. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] HP105B HP 105B 1 amp fuse blowing
Hi I would dump the batteries. If you need backup, run a UPS or some sort of external DC setup. Batteries inside something like the 105 only seem to lead to messy problems down the road. Bob > On Oct 10, 2019, at 2:10 PM, Roy Thistle wrote: > > Hi All: > A 105B (quartz oscillator) is blowing the 1A fuse, after it is on about 1 > hour. > The fuse appears to have just melted (not a black mark as the result of a > flash, in the case of a high current short.)… just looks like the fuse wire > (inside the glass capsule) melted into some little blobs, for about 1/4 the > fuse length, near the middle. It wasn't a fast-blo or slow-blo fuse... just > the normal kind. > I think the unit is drawing just a little too much current, as the result of > the batteries needing charging (I had the fast charge option on when the fuse > blew.) And so, the fuse heated up, and finally melted. Not sure why the > batteries were not charging normally... but 20.1 volts is what I measured > across the pack, initially, and 23.4 V after about 45 min of charging. > I am charging the batters, from a power cube, at 510 ma, and dropping (cube > gives 25V, 500mA max)… the batteries are 20 C size NiCads, wired in series... > that of course is a retrofit. > I don't want to put another fuse in, and blow that too, without some > reasonable explanation of why the first one failed! > Please, any comments, or hints/suggestions... much appreciated. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
