A different way to Auto – Power – On your lilliput

intense · 04-30-2005, 01:46 AM

So I have read all the posts on doing the 150k and 10uf cap deal. Personally I think this makes a mess of the PCB board. So I have come up with another way, which moves this circuitry outside of the monitor case. This solution may not work for everyone, but for myself I am not using the stock casing so it doesn't matter.

Anyways here goes. My Idea is to use a momentary relay switch.

Assuming you have an additional 0.3 amps on your 12 volt rail to spare. You would splice into your 12volt +’ve power line coming to the lilliput from your computer's molex power connector. (or you could run 2 new wires from a new molex connector in your case up to the monitor. These 2 wires will hook up to the relay as shown on the attached diagram. The relay as you can see only gets power while the computer is on and powering the monitor. Now you do have to do some soldering but they are quick and painless. Your going to solder 2 wires one on each side of the power button making a parallel hook-up to the onboard power switch. These wires will run out of the monitor case (you may have to drill a hole) back to the relay. The 2 switch wires will hook up to the relay, again as shown in the diagram. I don't believe polarity is an issue for the switch connections.

How it works. "The capacitor allows the coil of the relay to be energized until the capacitor stores a charge, thus de-energizing the coil. The resistor bleeds off the charge of the capacitor when positive voltage is removed from the other side of the coil. You can increase the output time by simply changing the value of the capacitor. This one will give you about a 1/2 second output." (the 12volt.com)

I think this is much cleaner than anything I have seen thus far. Doing that 150k resistor and capacitor deal makes a mess of your pcb board. Taping the switch could come undone. Lastly shorting the switch leaves the other buttons useless on the board.

I have not tried this as of yet. Anything I have overlooked or any personal observations are welcome.

Hopes this gives people a different way to auto-power their lilliput.

So much grief, and I thought this monitor was designed for the car???
pffttt

xdjxklusivex · 04-30-2005, 03:29 AM

just use a remote :-P lol

stevieg · 04-30-2005, 04:22 AM

Quote: Originally Posted by xdjxklusivex

just use a remote :-P lol

yeah, that'll work if you've modded your screen into the dash and don't want any of the buttons, and don't want to ***** around with a remote whenever you get in the car.

intense, looks like a great idea to me

ming · 04-30-2005, 08:11 AM

I don't think you make a mess on PCB with a resistor and cap, if you have good soldering skills.

this solution uses more components and 4 wires to the PCB, probably not much better and certainly more complicated.

intense · 04-30-2005, 01:43 PM

xdjxklusivex -

I am the same way, I don't want to turn on the screen every time with the remote. I want to push the OPUS power button to start the entire system.

ming -

It uses a relay as 1 additional component, they are cheap and can be purchased for $2.99. Only 2 wires go to the button pcb not 4, the other 2 come from your pc or can be taken from your 12 volt power wire before it goes into your lilliput. As for it not being much better? compare the two methods and you tell me. 1 alters the onboard electronics of the main pc board, removing a resistor and adding electronics that were not there in the first place (not to say there is anything wrong with the design). or 2, a simulated button press. I don't see how it is much more complicated, like you said, if you have good soldering skills and can figure out how to hook up the cap and resistor to the main PCB board.

The only draw back I see is if your lilliput is not in the dash and you have the case sitting out in the open. Some might not like to have more wires running into the case.

I think this method is much safer. It is not like your screen is cheap either if anything goes wrong. Worse comes to worse, you ruin $4 of parts rather than $400. Again, it's just an alternative method.

CL

WebDog · 04-30-2005, 01:50 PM

Thats exaclty what i did with my tView, works like a charm, I have the M1-ATX so i hooked that up to the remote amp turn on ( since the tview needs a few sec od power before the switch will work).

I dont even have the switch panel connected, been running switch-less since feburary and no problems.

intense · 04-30-2005, 01:59 PM

you need the switch panel connected with the lilliput monitor, there is no way to turn it on otherwise.

xdjxklusivex · 04-30-2005, 03:02 PM

i was thinking about relocting the switch for the power button just soldering 2 wires to the board and extending it down somewhere to a momentary switch

intense · 04-30-2005, 03:08 PM

yep that works fine ... but you still have to push a button to power on the monitor... with the above solution the relay pushes it automatically for you

kingtut · 04-30-2005, 06:52 PM

intense, I like your idea, it is a lot mor elegant besides, the 8" screen does not have the same layout as the 7" so your idea should work for both.
Can you explain that diagram in english, I am lost with diagrams, the green wire [85] is confusing me. Also, what do you mean by "other side" -[30] connection-, how do I know which side on the button is + which is -. Thanks for the contribution.

intense · 04-30-2005, 08:34 PM

kingtut -

that’s true, I never thought about it that way but yes it should work for pretty much any type of monitor.

As far as the diagram goes its pretty straight forward. The pink line coming into the relay contact 86 is a switched 12 volt input. Basically when 12 volts is applied to contact 86 it energizes a coil inside the relay. This happens once your computer is started, power is sent up to the monitor and to the relay. While the coil is energized it flips a switch between contact 87 and 30 simulating a button press. Contact 87 and 30 simply run to the back of your lilliput power switch on the power switch circuit board, I believe this is separate from the main PCB board. You should see 2 contact points on the back of the pcb board where the switch sits. As I mentioned in my first post I don't believe that the switch has polarity which means no +'ve or -'ve. You would connect the wires one on each side of the switch contact points. It doesn't matter which side is connected to contact 87 and 30 on the relay. Then you have to hook up the lillilput ground wire or a black wire from your computer molex connector to contact 85 on the relay. However, before you solder the connection to contact 85 you have to put your capacitor (this has polarity so you have to watch your +'ve and -'ve here) and resistor in parallel in-between this connection.

if I have some time later I will do up another diagram ... but that should get you started.

intense · 05-01-2005, 12:59 AM

Here is a diagram to give you the basic idea.
Use the diagram as it is drawn at your own discretion.

Blue ZX3 · 05-01-2005, 01:40 AM

Let me post an observation that I noticed that my screen(Liliput) does. I have not read any thread that decribes this behavior...OK now the details....

First, I have it powered with my OPUS..
when first powered up it comes on in standby(power light is red) by default...but here is the cool thing that works for me until i mod it into the dash...If I want it to be on when I power up the computer( linked to my alarm

) then I just leave it on when the computer goes into standby mode, cause it seems to return to whatever state it was in when it was power was cut. I don't know if there are a diff versions of the this screen. I was going to do one of these mods but then I noticed this cool trick...

Any comments on other screens...is mine the only one..

Arathranar · 05-01-2005, 01:49 AM

One comment - when it's in standby mode like that the lilliput is still drawing about 1/2 it's normal current draw - around 400mA if I remember correctly. So you better have a big battery connected or you'll be in trouble. Check the lilliput FAQ for exact values.

Arathranar · 05-01-2005, 01:51 AM

I don't get how this is remotely simpler or easier than just putting a resistor and capacitor inside the lilliput. That requires less circuit building and fewer solders (since your circuit still requires the cap & resistor).

I went for the even simpler single 100uF capacitor approach and was done in under 1/2 an hour - most of which was careful opening and closing of the case.

User Name		Remember Me?
Password