---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 04/02/21: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:33 PM - Re: Poor Man's Battery Tester (user9253) 2. 04:10 PM - Garmin 400 series display replacement (GTH) ________________________________ Message 1 _____________________________________ Time: 02:33:33 PM PST US Subject: AeroElectric-List: Re: Poor Man's Battery Tester From: "user9253" XH-M609 Low voltage shut off I purchased this module for about $5 on eBay from a seller in China. The relay is SPST. The digital display is not steady but flickers or oscillates between a higher and lower digit. That is annoying. The displayed voltage is 0.5 volts lower than the actual voltage. The module did not come with any instructions. I learned how to use it via trial and error. There are two things that need to be set, hysteresis and low voltage shut off. Press and release the button on the right to see the hysteresis set-point. To change the set-point, push the right button twice while the set-point is displayed. The decimal point will flash, indicating that it is in set mode. Press the buttons labeled + and to raise or lower the hysteresis set-point. I set mine at 1.5 volts. If set too high, the relay will not energize. Dont dawdle because the display will revert back to battery voltage after a few seconds. Press and release the button on the left to see the low voltage shutoff set-point. To change the set-point, push the left button twice while the set-point is displayed. The decimal point will flash, indicating it is in set mode. Press the buttons labeled + and to raise or lower the low voltage set-point. I set mine at 10.5 volts which is actually 11 volts because the display is a half volt lower than the actual voltage. As suggested by Bob, I used two series diodes (1N4148) in parallel with the clock to limit the clock voltage to 1.5 volts. A 2K ohm series resistor limits diode and battery current to 50ma. I did not want to damage the clock by soldering. So I cut a wooden dowel to the same length as an AA battery. I installed this wooden battery into the clock along with the clock power wires pinched between the wood and battery contacts. Do not make the mistake that I did and use too small wires between the battery and XH-M609. The relay chattered because too much voltage was dropped across the battery wires. The XH-M609 saw low voltage and shut off the relay. With the load shut off, the voltage increased, the relay energized. This repeated over and over. The relay sounded like a buzzer. I then used 14AWG wires and all was well. The load that I used is an old automotive incandescent fog light. With a battery connected to the test circuit, the clock ran for 70 minutes before it shut off. Although the XH-M609 has its faults, it worked as intended to shut off the load when battery voltage dropped to 11 volts. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=501213#501213 Attachments: http://forums.matronics.com//files/battery_load_tester___221.png http://forums.matronics.com//files/battery_load_tester__157.jpg ________________________________ Message 2 _____________________________________ Time: 04:10:15 PM PST US From: GTH Subject: AeroElectric-List: Garmin 400 series display replacement Hello all, Our Garmin GPS 400 memory battery was successfully replaced some months ago, thanks to the advices on the list. Here is a small summary which could help (only in French at the moment, but if you ask...) http://contrails.free.fr/instruments_bat_gps.php Now another issue : the display begins to show some faded areas. Question : does someone on the list know of a source for a replacement screen? Any input appreciated, Thanks in advance, -- Best regards, Gilles http://contrails.free.fr http://lapierre.skunkworks.free.fr ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.