ULN2803A wont turn on parking brake

[kurt-olsson]

Hi!

I am trying to setup the ULN2803A for the first time.
I think i have gotten all the wires setup correct.
The power supply turns on and delivers 12v.

But i cant turn on the current to the parking brake light.

Is it just to: digitalWrite(pinNR, HIGH); for it to start opening the current?

I have added a couple of images to show how i have connected it.

[727737Nut]

Can't tell for sure but it looks wrong.  Check these links out,

http://www.instructables.com/id/Controlling-High-Power-Circuits-with-Arduino-and-D/


http://dduino.blogspot.com/2012/03/arduino-uln2803.html

[kurt-olsson]

Thanks. I looked at those and i cant see anything wrong with my setup.
Ive tested the multimeter for all connections. Maybe i will try another driver chip.

Must be something i have overlooked...

[727737Nut]

Tell me what pins you have connected and where they go to and from the ULN2803

[kurt-olsson]

Sometimes i feel like such an amateur...

i didnt solder the ULN2803A chip due to "just testing" it turned out it was bad connection to the board.

Now i am watching my parking brake fade in and out.


Honesly... This is the coolest thing ever! Cant wait to get the Korrys up and running!

Sorry Rob for taking your time. I will try to be more "professional" =)

[727737Nut]

No worries  Glad you got it working

[quid246]

ULN2803's are great when you can have the option of switching GND.

In the chance you ever need to switch actual voltages, this chips from Toshiba do the trick...

http://www.digikey.com/product-detail/en/0/TBD62783APG-ND

[kurt-olsson]

Cool!

I think i will use one for each 28v,12v and 5v.
They are extremely cheap.

I am glad i found these before starting to mess with n-channel mosfets.

Besy part is to paralelle connect 4pins and boom, 2amps! Thats really nice.

My mcp bulbs draw 2.4 so i have to think of something special for that one. (Cant draw more than 2amp even if connect 8pins. Will have to look that up)

I wonder what the average draw from the boeing backligt is, but i guess not more than 14-16 bulbs a panel. Should be doable.

[kurt-olsson]

Looks like a mosfet is recommended when putting larger amount of current through it.

Think i will be using it for the heavier stuff such as backlight.