Hi Ian, Goodonya mate.
How nice it is to see a bit of creditable, authoritative, advice offered up here gratis. Keep up the good work. Incidentally, many years ago, I recall a fellow club member having a cockpit fire in his glider due to an electrical fault, which resulted in the burning wire insulation generating huge amounts of dense chocking fumes in the cockpit, over a VERY short time frame. He survived – just, because he was directly above the airfield, at about 1000’ and was able to quickly land the glider. Your comments here would be very much appreciated. Regards, Gary From: Aus-soaring [mailto:[email protected]] On Behalf Of Ian Mc Phee Sent: Sunday, 5 March 2017 11:29 PM To: Discussion of issues relating to Soaring in Australia. Subject: Re: [Aus-soaring] Voltage drop I like 18gauge aviation wire for single seaters and prefer 16gauge for 2 seaters so guess rear fin battery may need 14gauge.. Fuse quality can also cause voltage drop and in rare occasions switches. With 3 batteries I like a C&K 7211 switch which you can call ON ON ON a 3 position switch. Personally I would look for 0.2 volts maybe 0.3 volts drop when transmit between volts at battery and volts at instrument panel. A few years ago there was a German factory wired glider had 1volt drop between battery and panel and it had its battery at the base of the panel so very short wire run. The owner was shocked Re aerial wire I like RG400 rather than the more usual RG58 but it is expensive. Regretfully when a glider gets a broken back on several occasions the coax is stretched considerably. . The coax is repaired but the SWR is not checked Ian McPhee 0428847642 Box 657 Byron Bay NSW 2481 On 5 Mar 2017 1:13 pm, "Mike Borgelt" <[email protected]> wrote: Well you can size the wiring properly by referring to the tables in AC43. Nobody here seems to know what reference the German glider manufacturers use, if any. Bernard could presumably just ask Schleichers. In any case, just measure at the battery terminals and at the instrument with the same load. As Bob Dircks says, there can be drop in switches, connectors and fuses. In any case what matters operationally is what voltage appears at the instrument because that is what will stop it working when it gets too low. So I'd just set the offset to zero. I've seen too many dodgy wiring installations. If you have to wiggle the connector to get it to work it is no good and probably won't work for long. In one memorable instance about 20 years ago a club had some vario problems. After investigating they found 12 volts at the battery and 8 volts at the instrument. After re-wiring they let me know that everything now worked fine, including the radio which hadn't been working properly SINCE THE FIRE DOWN THE BACK 18 MONTHS BEFORE. Mike At 11:38 AM 3/5/2017, you wrote: naturally the germans involved would...ask a silly question, even a rhetoric one. On 5 Mar 2017, at 11:58 AM, Mike Borgelt < [email protected] <mailto:[email protected]> > wrote: Refer to AC43 but measure anyway. Who knows what the German glider manufacturers do with wiring. Mike At 10:52 AM 3/5/2017, you wrote: Hi Bob Many thanks for your quick reply. I realise that the size of the wiring comes into it but I was working on the assumption that the electronic specialists amongst us would know what wiring the manufacturers usually use for this applications. BTW, I’m not blaming the wiring, I just need to arrive at a realistic figure for the offset in my LX 9000. Kind regards Bernard On 5 Mar 2017, at 11:11 am, Bob Dircks <[email protected]> wrote: In order to calculate the voltage drop, we would need to know the exact conductor size of the wiring. Of course the circuit is actually going to be 22m in length. You can (fairly) easily measure the voltage drop with a voltmeter, to measure the voltage at both locations while the load is applied. Normally one would not expect a significant drop at 0.9 A over 11m of a wire chosen carefully for the job. However, all joints in the wiring, including switches and breakers need to be considered, before blaming the wiring. Bob Dircks On Sun, Mar 5, 2017 at 11:32 AM, Future Aviation Pty. Ltd. <[email protected] > wrote: Good morning all Today I have a question for the electronic specialists on this forum. My new ASH 30 Mi has approx. 11m of electrical cable between the avionics battery in the top of the fin and the front instrument panel. What voltage drop can be expected at the panel if the combined avionics draw approx. 900 mA? This information would be helpful to properly adjust the voltage offset in the LX 9000. Many thanks in advance for your help and assistance. Bernard _______________________________________________ Aus-soaring mailing list [email protected] http://lists.base64.com.au/listinfo/aus-soaring _______________________________________________ Aus-soaring mailing list [email protected] http://lists.base64.com.au/listinfo/aus-soaring _______________________________________________ Aus-soaring mailing list [email protected] http://lists.base64.com.au/listinfo/aus-soaring Borgelt Instruments - design & manufacture of quality soaring instrumentation since 1978 www.borgeltinstruments.com <http://www.borgeltinstruments.com/> tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784 : int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia _______________________________________________ Aus-soaring mailing list [email protected] http://lists.base64.com.au/listinfo/aus-soaring _______________________________________________ Aus-soaring mailing list [email protected] http://lists.base64.com.au/listinfo/aus-soaring Borgelt Instruments - design & manufacture of quality soaring instrumentation since 1978 www.borgeltinstruments.com <http://www.borgeltinstruments.com/> tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784 : int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia _______________________________________________ Aus-soaring mailing list [email protected] http://lists.base64.com.au/listinfo/aus-soaring
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