Derrickearly Posted November 20, 2019 Report Posted November 20, 2019 My oem clock stops running when the master switch is off. If I let it run continuously by routing power from the battery directly, will I regret this? Quote
EricJ Posted November 20, 2019 Report Posted November 20, 2019 7 minutes ago, Derrickearly said: My oem clock stops running when the master switch is off. If I let it run continuously by routing power from the battery directly, will I regret this? Which clock do you have? Some draw more current than others. An LCD clock like the AstroTech LC-2 draws almost no current and could be fine, but others draw a significant amount and could drain your battery over time. Quote
Derrickearly Posted November 20, 2019 Author Report Posted November 20, 2019 My clock is at the top right. I'm thinking that it is powered only when the master is on for a reason. Quote
Bolter Posted November 20, 2019 Report Posted November 20, 2019 On my J (1983 model) the clock has its own unswitched power with a small inline fuse, from the factory. Without it, the clock will not keep time, as it has not battery of its own. I think the circuit is shared with the interior lights that if left on will drain your battery. The clock has not made an impact on battery life, even with some unplanned longer parking over 30 days. YMMV, -dan 1 Quote
Hank Posted November 20, 2019 Report Posted November 20, 2019 The clock in my Mooney is powered every time I repetitively twist the setting arm on the lower left, without lifting it up to move the hands. Runs for several days. This action is on my Pre-Takeoff checklist; in cold weather, I wind it and put on my Halos between pumping the throttle and turning the key, to give the cold fuel more time to evaporate. 1 2 Quote
RLCarter Posted November 21, 2019 Report Posted November 21, 2019 2 hours ago, Hank said: The clock in my Mooney is powered every time I repetitively twist the setting arm on the lower left, without lifting it up to move the hands. Runs for several days. +1 for Spring Power 1 Quote
MBDiagMan Posted November 21, 2019 Report Posted November 21, 2019 (edited) I have an electric LCD clock like that in my Cessna. It runs all the time, master on or not and has no significant current draw. Keeps absolutely perfect time too. My suggestion is to wire it into the battery properly and enjoy having correct time all the time. That said, if you fly with iXXX gadgets, do you need it anyway? Do you use the sweep second hand for your IFR timer? Edited November 21, 2019 by MBDiagMan Quote
carusoam Posted November 21, 2019 Report Posted November 21, 2019 I like the classic wind-up as Hank has covered... What is getting lost in the discussion of power used, and battery capacity... Any electric motor built in the style of the 70’s, will drain any battery you have connected to it... even if the battery is built in the style of the 90s... If the clock has real mechanical hands and you didn’t have to wind it up... it is driven by a small inefficient electric motor... The same thing would happen with cars built in the 70s... It probably doesn’t get noticed if the vehicle gets used every week... It becomes noticeable if it is a one day a week car, or the battery gets a bit weak... skip a day of use, 13 days later you are trying to start on a very low charge... The OP’s PO probably figured this out and disconnected the hot wire, and accepted the fact setting the clock prior to use was best for him... Digital clocks are much more efficient, electrically... as long as they don’t have a light left on them... electric motors and old light sources are great at generating lots of heat for each useful thing they do... Efficiency is everything... Best regards, -a- 1 Quote
Derrickearly Posted November 21, 2019 Author Report Posted November 21, 2019 Just a pet peeve of mine to have a clock read the correct time when you look at it. Quote
carusoam Posted November 21, 2019 Report Posted November 21, 2019 Compare one pet peeve to the next... which is more annoying... resetting the clock before flying charging the battery before flying Swap out the old clock for a fancy new clock... have you seen the price of a decent clock lately? Then make sure it knows daylight savings time, and time zones... and advises you when it has updated... Best regards, -a- 1 Quote
flyboy0681 Posted November 21, 2019 Report Posted November 21, 2019 19 hours ago, Dan at S43 said: On my J (1983 model) the clock has its own unswitched power with a small inline fuse, from the factory. Without it, the clock will not keep time, as it has not battery of its own. I think the circuit is shared with the interior lights that if left on will drain your battery. The clock has not made an impact on battery life, even with some unplanned longer parking over 30 days. YMMV, -dan Oddly, the fuse to the clock on my '83 is located at the battery terminal. I would have thought it would be located somewhere under the panel. Quote
Derrickearly Posted November 21, 2019 Author Report Posted November 21, 2019 4 hours ago, carusoam said: Compare one pet peeve to the next... which is more annoying... resetting the clock before flying charging the battery before flying Swap out the old clock for a fancy new clock... have you seen the price of a decent clock lately? Then make sure it knows daylight savings time, and time zones... and advises you when it has updated... Best regards, -a- Any recommendations on a new clock? Quote
Bolter Posted November 21, 2019 Report Posted November 21, 2019 54 minutes ago, flyboy0681 said: Oddly, the fuse to the clock on my '83 is located at the battery terminal. I would have thought it would be located somewhere under the panel. Yes. That is how mine is, as well. The inline fuse is near the battery. Quote
EricJ Posted November 21, 2019 Report Posted November 21, 2019 3 hours ago, flyboy0681 said: Oddly, the fuse to the clock on my '83 is located at the battery terminal. I would have thought it would be located somewhere under the panel. Since it bypasses the master switch and busses, the wiring to the clock isn't protected by the fuses or circuit breakers associated with those. In order to protect the wiring, the fuse/circuit breaker has to be near the source of the power, since any short between the fuse and power source won't be protected. Since the clock is driven directly from the battery, the fuse needs to be as close as possible to that. Same thing for battery tenders; the fuse or circuit breaker needs to be as close to the battery connection as possible. 2 Quote
carusoam Posted November 22, 2019 Report Posted November 22, 2019 9 hours ago, Derrickearly said: Any recommendations on a new clock? https://mooneyspace.com/search/?&q=Clock&page=2&search_and_or=or&sortby=relevancy The search has also uncovered the ‘hot keep alive’ circuitry, and what else may be attached to it... briefly... Around MS... you will find people that like their clocks... From... Wakmann 8 day clocks... Astro-tech LC-2 Aerovonics AV20, AV30 (fancy back-up AI with the clock) Davtron 811B A13A1 ? Mid continent MD93 that has USB ports on the front.... Aviation clocks are expensive jewelry, since my iPad does all the timing functions I need... Might as well get something certified, digital, and comes with extra skills... The aerovonics entry has many skills... but don’t trust the sensorless AOAi for anything but a parlor trick... PP thoughts only, stuff I have read about here... Best regards, -a- 1 Quote
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