Gemini 2 unit resets to default??
开云体育Hi Magnus,There’s a known bug in the clock chip (this isn’t something that Losmandy can fix with a firmware update). ?When the battery is changed and it loses the date & time, it starts in a state that causes it to drain power rapidly UNTIL you set the date/time (and then everything is normal again). There are a few techniques to change the battery to avoid this. 1) ?Replace the battery with the unit powered off. ?Once the new battery is installed, immediately power up the Gemini and set the date/time. ? BTW, you do not need to have the Gemini connected to the mount when you do this. ?So if the mount is in an observatory but you’d rather do this inside where it’s warm … just disconnected RA/Dec cables, remove the Gemini module from the mount and bring it in to change it. ?It will likely complain that the motors aren’t working but… this wont affect your ability to set the date and time (and you know the reason the motors aren’t responding is because they aren’t connected. 2) ?Replace the battery while the unit is powered on (running on 12v power). ?Take care here to not touch any of the exposed electronics, ?But since the unit technically never lost power it will still have the date/time set. I typically just do method #1 and I always immediately re-order a spare battery (I find local stores tend to not have these sizes so I never want to get caught with a dead battery and no spare). Scott has a YouTube video where he shows how to swap the battery. ?He uses a simple piece of scotch tape so that when he lifts the battery retaining spring he can just pull on the tape and the battery comes out easily. As for voltage… The mount runs on 12v-18v power. ?The electronics are completely happy with 12v power. ?BUT… if you run the mount on higher voltage then you get more torque to the motors (especially useful if you have a heavy load). ?If you are running a light load … go ahead and stick with 12v power. ?? Clear Skies, Tim
|
|
I just changed the battery in my gemini 2 mini and I used my gps module from losmandy when I powered it back up and it reset time and date pretty quick.? I did this because I'm using a TP-link and my ip address on one startup is 192.168.0.111 and the next time may be 192.168.0.100 which affects connecting. The battery did not solve this. I have 3.2 volts according to a meter and the web interface. ( Which is really really cool). What is the best thing to get to increase voltage to the gemini to improve the torque if you guys dont mind me asking here?
Greg |
开云体育I just purchased a waterproof 12V -> 18V DC-DC converter from eBay with a ?8A rated capacity – works fine.? They’re still selling them for about USD20 or so (see eBay item number 162987841478). ? I couldn’t begin to make one for that price!!! ? David From: [email protected] [mailto:[email protected]] On Behalf Of Greg via Groups.Io ? I just changed the battery in my gemini 2 mini and I used my gps module from losmandy when I powered it back up and it reset time and date pretty quick.? I did this because I'm using a TP-link and my ip address on one startup is 192.168.0.111 and the next time may be 192.168.0.100 which affects connecting. The battery did not solve this. I have 3.2 volts according to a meter and the web interface. ( Which is really really cool). What is the best thing to get to increase voltage to the gemini to improve the torque if you guys dont mind me asking here? |
|
The converters are a nice idea. It pumps ~12V DC input, to the correct polarity 17V output (adjustable internally) to the Gemini unit.? It has also has an output voltage and output current meter on it, so I know if there is a motor or gear jam issue by unusual current above normal.? It acts like a power dashboard for my Gemini units.? It aids in worm adjustment also by showing if the worm is jamming.? With the voltage booster I also provide a? 115VAC to DC 12V 5amp unit. Also, a simple cigarette lighter cord unit can provide field power ~12V, and this gets pumped to 17V for better DC motor torque. I have the cigarette adaptor cords too.?? Anyway, let me know privately if interested.? All the best, Michael On Thu, Oct 3, 2019, 10:03 AM Brian Valente <bvalente@...> wrote:
|
开云体育I've run my systems on 12v power for years... but recognize that "12v" is a bit of a colloquialism (12v power is seldom *actually* 12 volts). ?A fully charged lead acid battery is always delivering over 13 volts ... e.g. 13.8v for a new lead-acid battery at full charge. ?After a few years the same battery maybe only charges up to 13.4 volts.... (give or take). ?But if a lead-acid battery wont charge to better than 13 volts... it's probably time to think about replacing it. ?It might be fair to say that your "12v" battery is supplying somewhere around 13.5?? ?The best way to know is to use a meter to test it.I've never had an issue with my mount... but somewhat recently I made some changes. 1. ?I switched from lead-acid (which weighs a ton) to Lithium packs (much lighter). ?But the problem is the Lithium packs (not sure if it's just my particular model or if this is generally a "a thing" with Lithium batteries) is that when FULLY charged, they just barely supply 12v (I've measured it at just 11.9) and as they drain, it can drop to around 10.8. ?But it's Lithium... so I can run them down to empty. 2. ?I bought a new optical tube and this optical tube weighs in at 45 lbs. ?By the time you add other accessories (cameras, finder scope, etc.) it's a bit over 50 lbs (I have 53 lbs of counterweight). ? So I'm thinking ... maybe upping the voltage a touch wouldn't be such a bad idea even though I have never had an issue. So I bought one of these: SMAKN Waterproof DC/DC Converte 12V (9V-13V) Step UP to 15V/15A 15V 15A 225W Power Supply Module by SMAKN: https://www.amazon.com/dp/B00UYCU0A4/ref=cm_sw_em_r_mt_dp_U_RWMLDbWJSB04N I do not believe in using the "cigarette lighter" style plug -- the only electric receptacle that was actually designed so that thing you plug into can self-eject. ?I'm thinking I want something that has a better connection. ?I converted to Anderson "Power Pole" style plugs (I've been converting my friends over to these things one by one... and everyone loves them). ?I can't take credit for this discovery... I'm told HAM radio operators have been using them for years. Keep in mind that the "Gemini" controller (the electronics) is TOTALLY happy with 12v power. ?You will not improve reliability of the electronics by upping the voltage (that will just get converted right back down to whatever the voltage is that runs the Gemini internally ... I'm not sure if it's a 5v system or a 3.3v system and possibly someone here can answer that, but I suspect the boards in the Gemini do not run on 18 volts. When I bought my Losmandy StarLapse ... it was either Scott or Tanya (probably Tanya) who told em that the StarLapse (they no longer make this system) is actually the RA motor from the GM8 mount ... but modified to attach to a photo tripod. ?Also since it's just an RA drive, it doesn't use a Gemini... it has it's only small box that lets you set the direction and drive rate. ?Anyway, they told THAT system runs on ANYWHERE from 7 - 18 volts (quite a range) and that the ONLY thing you get from running a higher voltage is more torque at the motors ... and this assumes you have a load heavy enough to where having the torque is an advantage. ?If you don't have a heavy load ... you don't need the torque. When I bought my heavier scope... I adjusted the max slew speed to 600 (down from the 800 which I think was the factory default). In addition to the G11 mount ... I also own a GM8. ?The GM8 has my TeleVue refractor on it. ?It uses the 7 lb counterweight (even with cameras). ?So I figure I'm probably not in much danger of overloading the thing. ?I didn't bother to up the voltage or slow the slewing rate. On Oct 3, 2019, at 4:00 PM, Brendan Smith <brenatlilydale@...> wrote:
|
开云体育I think you mean piqued … ? David ? From: [email protected] [mailto:[email protected]] On Behalf Of Greg via Groups.Io ? ?Brian no I have no problem with torque. It just peeked my interest. |
|
Magnus, I just got a Gemini-1 unit with similar issue: ?it was going back to default values at boot up, because the backup battery was always going dead.? I think it has a bad BAT54 schottky barrier diode, so the 5V power when on, or ground voltage when off, was going directly to the backup battery, killing the battery. But it would boot up fine, just always with default values!? ?On the G1 design the BAT54 is supposed to isolate the battery from the 5V power...but when that fails, the battery is either drained to ground, or overdriven by 5V. ? So remove and check your backup battery... See if it is reading a good voltage. If not, maybe the Gemini-2 circuit has a problem.? Brendan Smilth in Australia is a genius with the G1 systems, and so is David Partridge in the UK.? Maybe they can speak to the G2 circuit behavior that might cause a similar behavior. ? Anyway... just another idea as to your weird G2 behavior... ?(I have never examined its circuitry...only G1s...) Best, Michael On Fri, Oct 4, 2019 at 4:25 AM Tony Gabriele via Groups.Io <tgabriele73=[email protected]> wrote: Would it be possible to get a link to the video you referred to in your reply? --
|
Timothy Campbell
Greg
David C. Partridge
Michael Herman