Korry 318 cant figure out the diagram.

[kurt-olsson]

I am having troble to identify the circuit closed for the pushbutton test and also i cant get it to light up. (Tested with 5v)

Can anyone help me to tell how the wiring should look like?

I am getting circuit closed "sometimes" on 1-4, but its not a solid circuit so i am confused about this one.

Maybe 5v wont even lit them up as test as they req 28v? Still, funny that i cant find the common with my multimeter...

[727737Nut]

I want you to learn here so here goes.   Read the schematic on the Korry it'self.  What components does it show?  Why can't you read resistance in the circuit?   You need at least 12 volts to test but it is designed for 28Vdc.   Give me some answers and i'll help you from there.  This very basic electrical that you need to know.

Rob

[kurt-olsson]

This will be fun.

I really think it should work my way but doesent. It will be fun to see where i am wrong.

Step 1, i have identified that i have a korry 318 type 1 and this is the diagram i am using:


Terminal 1: here goes the 28v + in.
The circuit goes all the way from 1 through the two lamps and out to terminal 2. This is a closed circuit. I think i should be getting a solid signal with my multimeter. And also light up the lamps a tiny bit with 5v even if it demands 28v.
The component after the lamp seems to be a diode rectifier that converts ac to dc.

Terminal 2 and 3 is closed circuit if not pushed.
Terminal 2 and 4 is closed circuid if pushed.

The two "dots" with a wire symbol before the other diode rectifier i cannot identify what it is...

What do u think of this?

[727737Nut]

Terminal 1: here goes the 28v + in.
The circuit goes all the way from 1 through the two lamps and out to terminal 2. This is a closed circuit. I think i should be getting a solid signal with my multimeter. And also light up the lamps a tiny bit with 5v even if it demands 28v.
The component after the lamp seems to be a diode rectifier that converts ac to dc.

28V in on terminal 1 is correct

You can not measure thru a diode with the meter set to read ohms.

The diode is forward biased at about .5vdc so already you are down to 4.5v at best.  No the bulbs will not light.  Use 12 if you must to test but they are designed for 28vdc.   
The comment about rectifier and AC, is incorrect.  Whats the purpose of the diode/ diodes in this circuit? 

Did you get the author's permission to use his blueprint you posted?

Rob

[kurt-olsson]

Ok 1/4 atleast.

If i understand correct a diode is a valve that ensures the electricity to flow in only one direction. And also to protect other components that needs a certain flow.

In this circuit i think they are used to protect from current in terminal 2,3,4 to get that much voltage.

No i did not get permission and i didnt know i needed one.

[727737Nut]

The diodes are used to prevent the flow of current in the control circuits and back feeding into undesirable places.  (much simplified)

Pin 1 is 28Vdc
Pin 2 is Grounded to turn the light on. 
Pin 3 is grounded from master test module  ( you don't need to worry about this one as flightsim does this function
Pin 4 is push to test function and it also is a ground.   

You only need pins 1 and 2 to make it all work.   Diodes can only be checked with either a meters special diode function or by voltage drop across the diode. 

disclaimer  I am not an engineer, I have only had some classes on electrical theory and basic practice. 

Rob

[kurt-olsson]

Thanks a million.

Now i understand that it was the Diode part that i didnt fully understand but now i should be able to make it work.

Atleast now i have the competence to solve 70% of the overhead.
Not sure if i want to go airnc 429 way on the irs display or just use my own leds. Would have been cool but this needs alot of understanding and also hardware.

Gauges i think i will use aftermarket or buy cheap ones and retrofit servos.

Thanks again, will post pictures after it is up and running.

[Wendy]

Sorry but you can measure diodes with a multimeter set to ohm's.
In one direction it will read almost 0 ohms and in the other direction it will block, so not read any ohm at all.

Regards, Wendy

[727737Nut]

Sorry but you can measure diodes with a multimeter set to ohm's.
In one direction it will read almost 0 ohms and in the other direction it will block, so not read any ohm at all.

Regards, Wendy

Disagree, just checked one on the bench and OL one way and 1.8Mohms the other.  Not a good way to check.  My .02c

[kurt-olsson]

One question...

I tested according to the diagram to connect 1 (12v) and 4 (push to test)
And the light goes on if i push the button just as diagram shows.
And if 1,2 (2 on off ground) i can control the light.

Rob, did you implement push-to-test function?

I will try to do some analog reads tonight but would like to know your setup.

[727737Nut]

I did not implement push to test, personal choice to avoid added wiring for a useless option in a sim.   I felt that the lights test switch was good enough to test the Korry.   

Rob

[kurt-olsson]

Hehe ok, i think its a cool feature so i will try to implement it.

[kurt-olsson]

Hmm i really suck at electronics!

I dont really see how i can identify if the button has been pushed...

terminal 2,3,4 are all grounds and i dont know how to be able to set them up so i can identify which ground is active.

if light is on and i push the button it will have the same value, also pin 3 will have the same value as 2 if not pushed...

Any ideas?

[KyleH]

Assuming it's the same as the diagram here: http://www.737flightsim.com/28v16v.html

Its a push to test....then just wire pin4 to ground and it should light up when you push it.

[kurt-olsson]

Thanks.

Yeah ive got that working. But what i want for my simulator to work is to know when the button has been pressed and then activate by using terminal 1 and 2.

But maybe this is impossible with the circuit in the korry.

The problem with my current setup with my uln2803a is that if i cut the power to terminal 1, it wont lit up...


Ohhh my god, i am so stupid!!!
I think now when i write i can just hook up one more ground on the uln2803a. If battery in the aircraft/sim is enabled i turn the ground on terminal 4 on.
This way i could also have different lightstrength on the test and normal lighting.

I have to try this...

Thanks for your input, you helped me think it through i think!

[kurt-olsson]

It works!!!

Now i have complete control of testlight and normal light!

Right now the normal is blinking and testlight if pressed is fading in and out!
This is so cooooool!!!