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#1
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On 7/29/11 4:51 PM, Tony V wrote:
With modern avionics/electronics you really should not need this. Modern radios, transponders, etc. have built in switch mode power supplies that effectively do the same as this device does, but usually more efficiently. Thanks, Darrell. The reason that I ask is that after flying for a few hours with a new 9Ahr battery, the LCDs on my radio (Dittel FSG71M) blank out when I transmit - which gets out OK. Other than the radio, I'm only running a Cambridge 302 and an iPaq. Tony V. Its hard to see what would be drawing so much power to drop the Dittel below its speced operating voltage. There was a recall/repair on some of these radios but I though that only affected the RF board, not sure that could affect the display like this but I don't know. Was yours affected? - check here http://www.cumulus-soaring.com/dittel.htm Other Dittel users can comment if they ever see this display problem at reasonable supply voltages. I've never owned a Dittel radio. I'd want to check that the 9Ah battery is not faulty or not getting fully charged (the charger may be faulty or incorrectly sized etc), something else/hidden is drawing power or the Ditel has a problem. It would be nice to do a discharge test on the battery after charging it as you normally would and see exactly what power it is storing. You can do this maually but much easier with a discharge tester like the West Mountain Radio CBT III. Improper charging is not an uncommon problem-check your charger is the right type, and sized for the battery and if it has indicators for charge/complete or float stage do they show as expected (and you still need to leave the battery on charge for many hours after that to top up the last ~10% or so). But if you can't do that at least measure the current your equipment is drawing and measure the voltage under load (all avionics on and transmit key pressed) when the Ditel starts misbehaving. I have numbers for common toys including the C302 etc. in slides at http://www.darryl-ramm.com/glider-batteries I think the radios are speced down to 9V and may work even lower, and with your setup just should not have problem after only a few hours. You would not be the first person to have something hidden behind the panel that is consuming power. Some PDAs can suck interesting amounts of power ( transponder) esp. if they have a large Li extended battery packs that are connected to the ship when discharged. A poorly designed PDA chargers might be very inefficient (but most are not). Still noe of these alone would really explain this. Maybe you have several things goign on. Certainly measure the current draw with everything turned on and see if it makes sense with what is in my slides. Also measure the current of each device. Darryl |
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Tony,
I am with Darryl on this, with your seemingly modern electronics and a new 9AH battery, you "should not be having a problem". But of course you do apparently seem to be having an problem. I say apparently as you say your Dittel display disappears when you transmit but it still "... gets out OK...". This seems like a problem with your radio, not with your battery or wiring. But here are some other ideas. What is the gauge of your wiring from the battery to your instrument panel? If you are using small gauge wiring, and drawing considerable amps when transmitting, then the voltage can drop considerably between the battery and your radio. I use 12ga wiring. 14ga generally works just fine. Anything smaller and you are throwing away voltage, which we glider pilots cannot afford. So measure the voltage of your power system at the radio when you hit the transmit key. If the voltage drops considerably (i.e. from 12.5VDC to 11.5VDC) then you either have a wiring/connection issue or your battery is bad. BTW: Only use Tefzel wiring in aircraft: http://wingsandwheels.com/tefzel_coa...kers_louds.htm. Battery Testing - Testing your batteries each year is a good idea. Darryl mentions a very nice battery tester which does a quick job of determining good from bad. Unfortunately, it costs $150 which is a bit steep for a once a year effort. So here is my (slow) poor man battery testing method that should not cost more than $10-$15: http://aviation.derosaweb.net/#batterytest Good luck. Enjoy, John DeRosa johnatderosaweb.com |
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On 7/31/2011 10:58 PM, John Derosa wrote:
Tony, I am with Darryl on this, with your seemingly modern electronics and a new 9AH battery, you "should not be having a problem". But of course you do apparently seem to be having an problem. I say apparently as you say your Dittel display disappears when you transmit but it still "... gets out OK...". This seems like a problem with your radio, not with your battery or wiring. So it appears. When it happened again today, I switched the 302 to the battery voltage screen and when I was transmitting (with the blank LCD display), the 302 was registering 11.6 volts. So, it appears that I have a radio or wiring problem. What is the gauge of your wiring from the battery to your instrument panel? If you are using small gauge wiring, and drawing considerable amps when transmitting, then the voltage can drop considerably between the battery and your radio. I use 12ga wiring. 14ga generally works just fine. Anything smaller and you are throwing away voltage, which we glider pilots cannot afford. So measure the voltage of your power system at the radio when you hit the transmit key. If the voltage drops considerably (i.e. from 12.5VDC to 11.5VDC) then you either have a wiring/connection issue or your battery is bad. BTW: Only use Tefzel wiring in aircraft: http://wingsandwheels.com/tefzel_coa...kers_louds.htm. I will be checking the wiring to the radio very closely. Battery Testing - Testing your batteries each year is a good idea. Darryl mentions a very nice battery tester which does a quick job of determining good from bad. Unfortunately, it costs $150 which is a bit steep for a once a year effort. So here is my (slow) poor man battery testing method that should not cost more than $10-$15: http://aviation.derosaweb.net/#batterytest This is nice. I typically test by putting a 1 Amp load on the battery (using a 1156 automotive light bulb). My charger is an accumate(http://www.accumate.com/612/), which IMHO is quite good. Thanks for the advice! Tony, LS6-b "6N" |
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On 7/31/11 8:23 PM, Tony V wrote:
On 7/31/2011 10:58 PM, John Derosa wrote: Tony, I am with Darryl on this, with your seemingly modern electronics and a new 9AH battery, you "should not be having a problem". But of course you do apparently seem to be having an problem. I say apparently as you say your Dittel display disappears when you transmit but it still "... gets out OK...". This seems like a problem with your radio, not with your battery or wiring. So it appears. When it happened again today, I switched the 302 to the battery voltage screen and when I was transmitting (with the blank LCD display), the 302 was registering 11.6 volts. So, it appears that I have a radio or wiring problem. What is the gauge of your wiring from the battery to your instrument panel? If you are using small gauge wiring, and drawing considerable amps when transmitting, then the voltage can drop considerably between the battery and your radio. I use 12ga wiring. 14ga generally works just fine. Anything smaller and you are throwing away voltage, which we glider pilots cannot afford. So measure the voltage of your power system at the radio when you hit the transmit key. If the voltage drops considerably (i.e. from 12.5VDC to 11.5VDC) then you either have a wiring/connection issue or your battery is bad. BTW: Only use Tefzel wiring in aircraft: http://wingsandwheels.com/tefzel_coa...kers_louds.htm. I will be checking the wiring to the radio very closely. Battery Testing - Testing your batteries each year is a good idea. Darryl mentions a very nice battery tester which does a quick job of determining good from bad. Unfortunately, it costs $150 which is a bit steep for a once a year effort. So here is my (slow) poor man battery testing method that should not cost more than $10-$15: http://aviation.derosaweb.net/#batterytest This is nice. I typically test by putting a 1 Amp load on the battery (using a 1156 automotive light bulb). My charger is an accumate(http://www.accumate.com/612/), which IMHO is quite good. Thanks for the advice! Tony, LS6-b "6N" It actually has to be _really_ thin wire to drop significant voltage at transmit current draws (because that current is just not that high - with modern radios typically about a bit over 1 - 1.5 amp @ ~12VDC transmit draw, say worse case 2 A all up, you can draw that through 10 feet of 24 AWG wire (finer than you should find in a glider) and only drop around 0.25 volt. So its worth checking the wiring and using heavier wiring can be good practice, but thickness of wiring causing this problem is kinda unlikely. One thing I would look out for if the wiring seems suspect is corrosion. Especially hidden behind heat shrink tubing and inside poorly made crimp connection. So if you can't sort anything else out carefully inspect connectors. Sometimes it hides in places like inline fuse housings and their connections etc. But overall I'm also suspecting your radio. It also may be worth thinking if this effect is temperature dependent (happens after the radio bakes in the sun for a while?). I've seen LCD displays exhibit all sorts of weird problems when they get hot enough. Darryl |
#5
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On Jul 31, 9:33*pm, Darryl Ramm wrote:
On 7/31/11 8:23 PM, Tony V wrote: On 7/31/2011 10:58 PM, John Derosa wrote: Tony, I am with Darryl on this, with your seemingly modern electronics and a new 9AH battery, you "should not be having a problem". But of course you do apparently seem to be having an problem. I say apparently as you say your Dittel display disappears when you transmit but it still "... gets out OK...". This seems like a problem with your radio, not with your battery or wiring. So it appears. When it happened again today, I switched the 302 to the battery voltage screen and when I was transmitting (with the blank LCD display), the 302 was registering 11.6 volts. So, it appears that I have a radio or wiring problem. What is the gauge of your wiring from the battery to your instrument panel? If you are using small gauge wiring, and drawing considerable amps when transmitting, then the voltage can drop considerably between the battery and your radio. I use 12ga wiring. 14ga generally works just fine. Anything smaller and you are throwing away voltage, which we glider pilots cannot afford. So measure the voltage of your power system at the radio when you hit the transmit key. If the voltage drops considerably (i.e. from 12.5VDC to 11.5VDC) then you either have a wiring/connection issue or your battery is bad. BTW: Only use Tefzel wiring in aircraft: http://wingsandwheels.com/tefzel_coa...kers_louds.htm. I will be checking the wiring to the radio very closely. Battery Testing - Testing your batteries each year is a good idea. Darryl mentions a very nice battery tester which does a quick job of determining good from bad. Unfortunately, it costs $150 which is a bit steep for a once a year effort. So here is my (slow) poor man battery testing method that should not cost more than $10-$15: http://aviation.derosaweb.net/#batterytest This is nice. I typically test by putting a 1 Amp load on the battery (using a 1156 automotive light bulb). My charger is an accumate(http://www.accumate.com/612/), which IMHO is quite good. Thanks for the advice! Tony, LS6-b "6N" It actually has to be _really_ thin wire to drop significant voltage at transmit current draws (because that current is just not that high - with modern radios typically about a bit over 1 - 1.5 amp @ ~12VDC transmit draw, say worse case 2 A all up, you can draw that through 10 feet of 24 AWG wire (finer than you should find in a glider) and only drop around 0.25 volt. So its worth checking the wiring and using heavier wiring can be good practice, but thickness of wiring causing this problem is kinda unlikely. One thing I would look out for if the wiring seems suspect is corrosion. Especially hidden behind heat shrink tubing and inside poorly made crimp connection. So if you can't sort anything else out carefully inspect connectors. Sometimes it hides in places like inline fuse housings and their connections etc. But overall I'm also suspecting your radio. It also may be worth thinking if this effect is temperature dependent (happens after the radio bakes in the sun for a while?). I've seen LCD displays exhibit all sorts of weird problems when they get hot enough. Darryl- Hide quoted text - - Show quoted text - My FSG -2T did the same thing out of the box. This was with a new 14v 10ah battery, and 14 ga wire. Dittel acknowledged it was defective and repaired it free of charge. |
#6
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Are you using circuit breakers instead of fuses? That might be worth
looking into. Breakers will cause a slight drop in voltage, but maybe you have a bad one causing a larger problem. |
#7
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On 8/2/2011 10:11 AM, Westbender wrote:
Are you using circuit breakers instead of fuses? That might be worth looking into. Breakers will cause a slight drop in voltage, but maybe you have a bad one causing a larger problem. I have a 5 Amp fuse at the battery and 2 Amp fuses on the panel for the individual components. Hans makes a very good case for checking the wiring. :-) Tony |
#8
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It is unbelievable what crappy electrical installations you can find
in gliders. In my 1997 ship, somebody installed a 25 wire printer cable as a power and signalling backbone under the seatpan. Nice to be able to disconnect the panel at the DB25 connector if needed, but... I had continuous problems with my voltage dropping off soon after launch to something like 11 Volts and my Dittel FSG71M starting to blink. I also ran a Terra250 and GPSMAP195 continuously. After the batteries tested good on capacity, I checked the wiring in more detail. My ship has 3 battery positions (front, main and tail) They were clever enough to combine 3 strands of the printer cable for the positive terminal of each battery position. I could not believe my eyes when I found out that they were running ALL ground (power and signalling) through a single strand of the 25 wire printer cable. If I were religious, I would have thanked God that the whole thing did not go up in fire in flight. My first project was to install a new separate power and ground backbone with 12AWG Tefzel. After that my power supply has been rock steady and pushing the PTT button has hardly any effect. Last winter I have replaced all of the remainder of the printer cable (signalling) with Tefzel. In the mean time also power hogs like the Terra has been replaced by a Trig and the GPSMAP195 by a Ipaq310. Then there is the never ending saga about batteries. There are 2 use modes that substantially shorten the life time/ capacity of a battery (holds for most battery chemistries, but particularly Lead Acid) - Deep discharge - Over charge Most common glider batteries (like the PowerSonic 7AH) are completely empty at 10.5 Volts at usual glider current draw (~1-2 Amps). See the PowerSonic spec sheet. Discharging to 9 Volts (at 1-2 Amps) is just damaging the battery. With a reasonable AC mains charger like a Battery Tender or similar 2/3 stage charger, over-charging should never be a problem. However, unregulated solar panel charging is a shortcut to premature end of life for the battery. As always on this forum, there are a hundred different opinions and a lot of yelling about who is right or wrong. I try to speak only about my personal approach and leave decision making to the reader. My approach is KISS. I have plenty of battery capacity on board. I have a good fat power supply (and ground) backbone in star configuration. I switch all 3 batteries in parallel. I have no need for elaborate wiring schemes for switching of batteries or separate batteries for separate equipment like transponder I don't deep-discharge batteries (below 12 Volts) to prolong life time of the batteries. I have no need for voltage converters to try to maintain 12 volts from a battery that is already empty (and damage the battery by doing so). I charge all batteries immediately after each flight. Each battery on a separate Battery Tender. The FSG71M, Trig, LNAV, Ipaq310, Etrex are running happily and I am sure the PowerFlarm will soon join without any problem. Works well for me, but if you want to follow a different approach, that is fine too. Hans Van Weersch |
#9
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"weersch" wrote
Then there is the never ending saga about batteries. There are 2 use modes that substantially shorten the life time/ capacity of a battery (holds for most battery chemistries, but particularly Lead Acid) - Deep discharge - Over charge Most common glider batteries (like the PowerSonic 7AH) ---------------------------------------------------------------------- My experience has been that leaving one sit around in a discharged condition will kill one permanently dead, just as quick as the other two reasons listed above. -- Jim in NC |
#10
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On 8/2/2011 11:53 PM, Morgans wrote
Most common glider batteries (like the PowerSonic 7AH) Is anybody *really* buying the 7AH battery? For just a little more money, you can get a 9AH battery with the same size and shape - http://www.voltdepot.com/product/27042.html Tony http://home.comcast.net/~verhulst/SOARING |
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