Cold protection

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   You tell me about temperature. One day it's misty, fog and rain and the next, 5 degrees below zero. These boxes then start behaving at their own discretion!

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BigDPS Members Profile Send Private Message Find Members Posts Add to Buddy List Beta Testers Joined: 13 Dec 2007 Online Status: Offline Posts: 471	Quote Reply Topic: Cold protection Posted: 12 Dec 2011 at 5:53pm
	You tell me about temperature. One day it's misty, fog and rain and the next, 5 degrees below zero. These boxes then start behaving at their own discretion!


LightsOnLogan Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 11 Oct 2007 Online Status: Offline Posts: 3187	Quote Reply Posted: 12 Dec 2011 at 8:50am
	So far keeping 200 watts of light (2 100W bulbs) attached to a thermostat and sitting on the side of the Q-Spot nearest the microcontroller is doing the trick at getting the Q-Spot to start up each day. When the show begins I turn off the "heater lights". During the night I have the channel set to be on for 10 minutes of every hour (minimal heating to prevent frost), and around midday I have the channel set to turn on continuous leading up to the show. The thermostat is set to 75F so once it hits that it starts cycling based on temperature. I have no idea why it became temperamental this year. In the past I've been able to start it up in single degree weather without any problem. Michael


LightsOnLogan Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 11 Oct 2007 Online Status: Offline Posts: 3187	Quote Reply Posted: 12 Dec 2011 at 8:42am
	As for RS-485 chips, I've been happy with Maxim 13082E this year. They are not MIL spec, but I figured I would give them a shot since the recommendation which led me to them came from Canada. Michael


LightChristmas Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Beta Testers Joined: 15 Oct 2007 Location: Equality, IL Online Status: Offline Posts: 993	Quote Reply Posted: 11 Dec 2011 at 5:31pm
	Minis are doing the trick. Think I now know how that UAV went down in Iran! Mil-Spec - lowest cost, worst reliability.


BigDPS Members Profile Send Private Message Find Members Posts Add to Buddy List Beta Testers Joined: 13 Dec 2007 Online Status: Offline Posts: 471	Quote Reply Posted: 11 Dec 2011 at 2:57pm
	Isn't it the way for things to happen, your display dies when you are the furthest away?


LightChristmas Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Beta Testers Joined: 15 Oct 2007 Location: Equality, IL Online Status: Offline Posts: 993	Quote Reply Posted: 09 Dec 2011 at 8:37pm
	Well, now I'm having temperature problems! The Mil-Spec -32F RS485 driver chips I replaced after last years debacle are doing the same thing the cheap Intersil chips were doing - killing the unit ID. Guess I'll have to stuff the enclosures with minis again this year. Of course, it decides to do this while I'm 50mi away at work.


LightsOnLogan Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 11 Oct 2007 Online Status: Offline Posts: 3187	Quote Reply Posted: 09 Dec 2011 at 9:31am
	I'm questioning the power supply damage. The unit completely froze up last night... to the point that even after turning it off and unplugging it entirely the text was stuck on the LCD (apparently being powered by an internal capacitor or battery) for 20 minutes. Only then was I able to reset the unit, and it started freezing during startup once again. It took 2 hours before I had it running again. I opened it up and inspected for cold solder joints, etc, but didn't find anything visibly amiss. There was a single dead ladybug on the mobo, but it wasn't contacting anything so I doubt the bug was an issue. Eventually it just started working again. Honestly, it is acting like a malfunctioning microprocessor (maybe damaged in the cold?). I'm going to move the heating lights to the area of the unit closest to the microprocessor and see if that helps. Michael


LightChristmas Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Beta Testers Joined: 15 Oct 2007 Location: Equality, IL Online Status: Offline Posts: 993	Quote Reply Posted: 08 Dec 2011 at 1:11pm
	There's no telling how badly abused the unit was before you got it. I'd keep the bulb as a "dire emergency" spare, though. Good thing the power supply wasn't damaged.


LightsOnLogan Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 11 Oct 2007 Online Status: Offline Posts: 3187	Quote Reply Posted: 08 Dec 2011 at 12:42pm
	I just replaced the lamp and it ignited right away in 38 degree weather, so hopefully that solves the problem. Inspection of the bulb envelope on the old bulb looks far better than I expected. The inner envelope is mostly clear except for some black near the electrode on the left in the picture (not sure if that one is the cathode or anode). That electrode looks to be in very bad shape though. There are numerous pits and blobs on the electrode... arc wander maybe? Michael Edited by LightsOnLogan - 08 Dec 2011 at 12:43pm


LightsOnLogan Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 11 Oct 2007 Online Status: Offline Posts: 3187	Quote Reply Posted: 04 Dec 2011 at 8:42pm
	I haven't taken apart the bulb housing yet (a real pain in the neck). I need a spare on hand anyway (single point of failure to mitigate), so I'm going to order a new bulb. I will check and/or replace it when the new bulb arrives. I should only have about 400 hours on the 2000 hour bulb, but I did buy the Q-Spot as a factory refurb and don't know for certain how many hours were already on the bulb when I got it. Keeping the plexiglass rain enclosure warm is helping (I don't have to take it in the house to warm it up), but only if I can keep the temp above 70F or so in there (which is certainly not normal). Yesterday it successfully started up on its own, but today it got past the row of blocks on the display and locked up with the word "Resetting..." on the display. The head made it to the home position, but the bulb did not ignite. A single power cycle brought it back to life and the bulb ignited that time. It did take about 12 seconds after the ignitor click before I saw the glow flicker on and start warming up. Michael