I have a HXr & HX. I have a second power supply from a second battery to both units. When powered by the second supply only I get a very dim screen on the HXr and non readable dark screen on the HX. Yes there is power on the HX.
Any thoughts on how to fix this?
Second power supply
Re: Second power supply
Need more info.
The odds of two efis boxes having defective power supplies is very small. What is the second supply? Can it supply the needed voltage (12) and current (4 amps)? Double check the wiring? What does the HXr say the voltage is?
The odds of two efis boxes having defective power supplies is very small. What is the second supply? Can it supply the needed voltage (12) and current (4 amps)? Double check the wiring? What does the HXr say the voltage is?
Re: Second power supply
I have dual batteries and dual bus. The second battery is supplying the second power supply to the DU's.
The voltage displayed on the HXr is (the only screen I can read) same as battery voltage, enough to run the DU.
The primary 12 volt input works fine.
I seems like it has something to do with dimming.
By the way I cannot find anywhere in documentation what the minamal operating voltage is for a DU.
The voltage displayed on the HXr is (the only screen I can read) same as battery voltage, enough to run the DU.
The primary 12 volt input works fine.
I seems like it has something to do with dimming.
By the way I cannot find anywhere in documentation what the minamal operating voltage is for a DU.
Re: Second power supply
Need more detailed info.
Are you using an ordinary diode in the second circuit somewhere? A normal diode will cost you 0.6 volts. Not sure the displays will work below 12.0 volts. Double check the wiring including the ground side.
Are you using an ordinary diode in the second circuit somewhere? A normal diode will cost you 0.6 volts. Not sure the displays will work below 12.0 volts. Double check the wiring including the ground side.
Re: Second power supply
If it was a ground problem the primary voltage input would not work!
If the volts are to low ( which there not) I don't think the
display would even come on.
There is no resistor!
If the volts are to low ( which there not) I don't think the
display would even come on.
There is no resistor!
Re: Second power supply
The obvious check is to swap pins - put the known-good main supply on the pin where you now have the backup, and put the backup into the pin where the main supply is now. As these pins are all next to each other they should all reach okay.
Re: Second power supply
Bob
I figured it out today and indeed it is a dimming issue. So let me explain.
So I have dual batteries and dual bus. I call them master bat and ESS (essential) bat. Dual EFIS, HXr & HX.
Both DU's are supplied off both batteries.
I have both both DU's on a external dimmer, power for dimmer off master bat and feed to the HXr thru a analog input for dimming.
The problem is when the DU's are being feed off the ESS bat only the screens go dim because the dimmer is feed off the main bat.
This is a real problem for those of you who have this type of set up with dual feeds and a external dimmer because if you loose your main power your going black!!
I have confirmed this by having the DU's power up by both bats and then turning the power to the dimmer off and the screens go black!
Not good!!! I hope this is software fix!
I figured it out today and indeed it is a dimming issue. So let me explain.
So I have dual batteries and dual bus. I call them master bat and ESS (essential) bat. Dual EFIS, HXr & HX.
Both DU's are supplied off both batteries.
I have both both DU's on a external dimmer, power for dimmer off master bat and feed to the HXr thru a analog input for dimming.
The problem is when the DU's are being feed off the ESS bat only the screens go dim because the dimmer is feed off the main bat.
This is a real problem for those of you who have this type of set up with dual feeds and a external dimmer because if you loose your main power your going black!!
I have confirmed this by having the DU's power up by both bats and then turning the power to the dimmer off and the screens go black!
Not good!!! I hope this is software fix!
Re: Second power supply
Here's how to fix your problem:
Measure the dimmer voltage at minimum setting. Let's say that's 0.8 volts. If in fact it's zero, add a resistor to the dimmer control to raise the minimum voltage above zero.
Now in the analog settings software, dimmer control, you get to set brightness levels. Set:
12 volts = 100%
6 volts = 50%
0.7 volts = 1%
0.6 volts = 100%
0 volts = 100%
Now a very low, like zero volts, gives full brightness. Of course the dimmer still won't work with no power, but at least it will default to full bright. Obviously set the first 3 numbers to your liking.
Measure the dimmer voltage at minimum setting. Let's say that's 0.8 volts. If in fact it's zero, add a resistor to the dimmer control to raise the minimum voltage above zero.
Now in the analog settings software, dimmer control, you get to set brightness levels. Set:
12 volts = 100%
6 volts = 50%
0.7 volts = 1%
0.6 volts = 100%
0 volts = 100%
Now a very low, like zero volts, gives full brightness. Of course the dimmer still won't work with no power, but at least it will default to full bright. Obviously set the first 3 numbers to your liking.
Re: Second power supply
Bob
That did the trick! Thanks for your help.
That did the trick! Thanks for your help.