Attaching a DC Barrel connector to 3/4" MDF

[slbailey]

OK so I'm starting a new bartop project and I want to do something I've never done before so I'm doing lots of research... Basically I want to build a fanless low power machine running just the early 80's arcade games... I'm gonna power it by a Raspberry Pi and a small 10" LCD I swiped from a dead laptop.  I want to go DC only and I've got a 12V/4A power supply that's powering the LCD monitor.

I want to run the power supply to a DC barrel connector, run 12V from that to the LCD and some LED light strips to backlight the marquee.  Then I want to run the 12V through a 12V-5V step down converter and power the PI (and USB devices) from that.

What I'm trying to figure out is how to attach a DC Barrel connector to the side panel... All the connectors I've seen are < 10mm long in thread length and that won't go through MDF.  Trying to find a solution here.

Any power magicians out there?

Steve

[JDFan]

All the connectors I've seen are < 10mm long in thread length and that won't go through MDF.

You could use one of these and just route out a larger area in the inside portion of the mdf so that the threaded portion is long enough to fit or large enough for a metal plate to be inserted and use the threaded connector mounted to the metal plate - same concept as flush mounting a joystick in the CP just from the opposite side of the mdf

[Slippyblade]

If you look at real cabinets, very little is actually attached to the wood directly.  In most cases, a cutout is made in the wood, the gizmo is attached to a metal plate and the plate is attached over or behind the hole.

[slbailey]

Not exactly what I was looking for.  Let me try a different question.  has anyone built a bartop using a laptop 12V power supply exclusively?  No power strip inside the unit... No 110V to the cabinet... A straight 12V power supply.

If you did, how did you get the power inside the cabinet?

[yotsuya]

If I were going to do it, I'd do it exactly the way Slippyblade described it. Don't overthink it. Barrel connector attached to a metal plate attached to the wood. I'd probably use a Pico power adapter as well.

[BadMouth]

Haven't done it with an arcade build, but in similar situations I've just put a little notch on the edge of whichever panel is removable to let the cable pass through.

A more professional looking solution would be to mount the female barrel connector there.
Having it on the edge and having the removeable panel notched out around it saves the hassle of finding a passthrough.

[Titchgamer]

Unless you are planing on useing a generator or something you will need to have your nominal voltage (110v?) to the machine anyways so you may as well use a standard IEC conector on the back of the machine and wire that straight to your 12v Transformer and work from there.

If you insist on not having mains Inside the cabinet I would suggest the best thing to do would be find a panel mount version of your DC socket.
You will need to know the internal and external dimensions of the jack to get the right one.
As far as I know they come in 2 types: Bolt on and screw mount.

If it is bolt on mount it into a small metal plate and then drill a big enough hole to push it through your cabinet and then mount it via the plate to your cabinet.


If its screw mount then you obv have to route out the recess for it. then screw it in place.

[slbailey]

The bolt mount is what I'm going to use.  I'm guessing my best solution is to wire one to the outside of the MDF and run jumper wire to another one mounted to the inside of the MDF and run a laptop power supply to the outside and a barrel connector from the inside to my components.

I was just hoping for a 3/4" or longer threaded bolt mount so I could just use one.  Imagine the control panel push buttons except for a power plug.

[Titchgamer]

To many joints!

Keep joints to a minimum.

Just mount the female dc jack to the cab and wire that straight to the components.
Also remember to put heat shrink or some other form of insulation over your bare terminations.

[JudgeRob]

I used a metal plate in one part.  In another I drilled an oversized hole in the back.  You could take something like this:
https://www.adafruit.com/products/610
and take a bigger (ie 1") drill bit to the back side about halfway through the board.  Then a smaller diameter from the front that matches your port.  That should give you room to reach in with needlenose or a screwdriver to tighten the nut.  I did the same thing on my CP with a keyhole switch that would only mount on a half-inch.

Also remember, you are not tied to a barrel jack.  You can use just about any kind of jack you want.  Just get one that can't be plugged in backwards!

[Slippyblade]

Just get one that can't be plugged in backwards!

No greater truth has ever been spoken.

[ed12]

slbailey
you are not reading enough
4a to a pi will be just over what it wants >current wise<
pi's take between 2.5-3 amps @5 volts to run proper
u only have 1 amp head room left.
lcd of any size take min. 1 amp to start up @12 volts dc
so just with them 2 alone u have no head room left.
head room as in the power supply
let alone conversion loss >12-5<
nor the leds
think current wise , then pick a power supply , then the type of plug u will need

ed

[JDFan]

Not exactly what I was looking for.  Let me try a different question.  has anyone built a bartop using a laptop 12V power supply exclusively?  No power strip inside the unit... No 110V to the cabinet... A straight 12V power supply.

If you did, how did you get the power inside the cabinet?

Even a laptop needs a power plug that goes to the AC outlet for charging !!

As for having the 110V AC converted to the 12V dc and 5V dc needed for your bartop (assuming you are using a 12V DC monitor and the 5V pi without using a power strip inside the bartop to plug in the various adapters - sure it can be done

You would need the 110V AC running to the 12V battery for charging ( Need a plug like above to attach the 110V when charging and unplugging once charged if wanting it portable.)

then internally you would want the 12V output split into 2 outputs - one runs to the 12V in for the monitor and one runs to a 12V to 5V DC stepdown that converts the 12V dc input to a 5V dc output and then the 5V output from there would be run to the Pi for power.

Similar to this that I tested for a 60 in 1 board and Dell monitor running from a single 110V source (rather than 12V battery) -- I have the monitor running to the 11V AC wall outlet ( you would instead run this off of a 12V battery to the monitor) then the monitor supplies 12V output off of the 12V DC output it has for the speakers ( which I use to power both a set of speakers and to a molex connector which hooks directly to the 12V wires and to the buck converter which reduces the voltage to 5V for the 5V wires of the molex which then connects to the 60 in 1 PCB to provide both the 12V and 5V it requires