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CFAH1602B-TMC-JP Backlight Questions

Satyr

New member
Ok, here's the deal... I'm going to get this: CFAH1602B-TMC-JP

The one that has the blue backlight, and I have a few questions that I would like to address before I go balls out here. First off, what I am going to (check my calculations please) is run the 5v rail to the LCD pins 3 and 4 or whatever they are as normal, off of that same rail I'm going to split it off to the LED backlight. Inline im going to put a 68 Ohm 1/2 Watt resistor and a SPST switch and then run it to the backlight. My question is, do I solder the positive and ground for the LED backlight to the A and K pins or 15 and 16? Just curious. Also, could someone refresh me on the correct way to wire an SPST switch, I can never remember what goes where on those darn 3 prong thingies! :p That's all for now, thanks guys!
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Satyr

New member
Hopefully, sooner than later, one of you guys @ Crystalfontz can help me out here! Really could use some validation of my assumption! THANKS kids!
 

CF Tech

Administrator
You are pretty much on track. The backlight dropping resistor calculation sounds correct.

A and K are connected to pins 15 and 16. You can connect to either set.

An SPST swith will have two terminals. Just put it in line with either the A or K and it will turn the backlight on and off. The TMC series is not much to look at without the backlight, so unless you want it off to remove a distraction or go undetected by enemy troops, I would just plan on leaving it permanently on--no switch at all.

If your switch has 3 terminals, it is probably an SPDT. No worry--just use the center and exactly one of the side terminals.
 

Satyr

New member
I doubt that you guys @ Crystalfontz will know, but I should give it a shot all the same. I want to encase the LCD in plexiglass of some sort and then run the cables from the "box" to the computer. My dilemma is this: power. I was thinking about taking some headphone jack plugs and running the power thru that so the thing is detachable easily but will that work? Can you push 5v thru that little wire? Can I even use those connectors?

Also, while im on it, know where I can get a sheet of Lexan or Acrylic and what the heck do I cut it with ?? Hah, yeah so I dont have the WHOLE thing planned out just yet!

Thanks again guys
 
M

MWP

Guest
Using a headphone jack will work fine... but you have to be careful when plugging it in/out. The headphone jack will short the supply as its removed and inserted and cause your PC to shut off (or kill the PSU) if its turned on.
So if you do use one, make sure your PC is off before plugging it in/out.

Or you could use a panel mount plug pack (power brick) style connector.
 

Satyr

New member
What exactly is a power brick style connector ??

Are there any other options that you can think of??
Thanks for your help
 
M

MWP

Guest
Its the type which have the cylinder outside connector and the other connector as a pin down the center.

Dont know how else to describe it.
 

Satyr

New member
Yeah, i believe I found what you are talking about. I went to RadioShack and they were called DC Power Jacks and Plugs. I'll post the link to the two items here and tell me if they look right to you. Also, how do I wire those up ?? I'm assuming the wire goes inside the plug somehow ?? Know of a place with a diagram or something?
Radioshack links:

DC Power Jack


DC Power Plug


Thanks MWP
 
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