I need someone to explain this to me.

Vaporizer rebuild

vaporizer-rebuild

Wait! Don’t click away yet. Yes, this is a vaporizer project, but it has the distinction of being the most electronics engineering oriented post on the subject we’ve ever featured. [Mm Nn's] vaporizer broke so he decided to fix it. After poking around inside it became clear that pretty much everything was trashed. So this ended up being a complete rebuild of all the support circuitry, with the heating element being the only electrical component he could salvage.

He started looking around for a power supply capable of driving the element from the Arizer V-tower vaporizer. He hoped that he could use a computer PSU but ended up having to buy one to suit; a Mean Well rs-100-24. He drives the system with a microcontroller (programmed in assembly) using PWM to adjust the element. Speaking of, there is a sensor built into the heating element that [Mm] isn’t using because he couldn’t figure out how to read from it. If you’ve got some ideas let us know in the comments.

 

The trials of repairing a MacBook

mac

As a favor to a friend, [Phil] traded a unibody MacBook logic board for one with a broken headphone jack, a busted keyboard controller, and a nonfunctional fan. Not one to let bad hardware go to waste, he set off to repair this now-broken laptop by scavenging parts wherever he could. The whole thing ended up working, and became a very impressive display of soldering skill in the process.

The first step for the keyboard transplant was to cut a properly sized hole in the newer unibody MacBook for an older, pre-unibody MacBook Pro 17″ keyboard. This was done by cutting out the keyboard pan of the pre-unibody case and very carefully epoxying it into the unibody chassis. The MBP had a separate keyboard and trackpad controller, so of course [Paul] needed to find some space inside the chassis for these new electronics. This space was found next to the internal hard drive, and a liberal application of hot glue held everything together.

In the future, [Phil] plans on adding more LEDs, a 3.5 mm jack, and a USB to TTL converter – a necessity for any true ‘hacker’ laptop. It’s still a wonderful piece of work, and an incredible amount of effort and skill to get it where it is today.

Laptop backlight converted from CCFL to LED

ccfl-to-led-backlight-conversion

[Lee Davison] acquired an Acer laptop that didn’t have a display anymore. He had enough parts on hand to add in an LCD panel and give it a CCFL backlight. But when he started looking for an inverter to drive the backlight he couldn’t find one. What he did have on hand were some smashed screens that had LED backlights and so the CCFL to LED backlight conversion project was born.

He tore into the LED display and found the driver board. Unfortunately he didn’t locate the datasheet for the exact LED driver, but he found one that was similar and was able to trace out the support circuitry on the PCB. This let him cut away the unneeded parts of the board without damaging the driver. He didn’t want to pull out the CCFL tubes until he was sure the LED conversion would work so he tried it out on another smashed panel (where does he come up with all these parts) and it worked great. Once he got everything in place he was very happy with the results. The only drawback to the system is that he doesn’t have the ability to dim the backlight.

Apple MagSafe cord repair

repairing-apple-magsafe

[Tommy Ward] had a big problem with the cord for his laptop power supply. This thing’s not cheap so he figured out a way to fix the frayed cord on his Apple MagSafe. He asserts that the shortened rubber collar on the plug end of the cord is to blame for this type of damage. We think rough use may have something to do with it too, but having had to repair our own feline-damaged power cords we’re not about to start pointing fingers.

To pull off an appropriate fix [Tommy] pries apart the case housing the power converter. This lets him get at the solder connections of the cord. After removing it from the circuit board he clips off the damaged portion of the cable. To reuse the strain relief grommet he drilled out the old portion of wire and insulation, making room for the undamaged cable to pass through, adding a cable tie on the inside to aide in strain relief. The last part of the fix involves gluing everything back together.

If your power supply problems have to do with the computer connector itself there’s a fix for that too.

DVD power supply repair tips

bridge-rectifier-repair

This demonstration fixes the power supply of a DVD player, but the skills transcend this one application. [Alan] walks us through the process of repairing a power supply (translated) on a simple consumer electronics unit.

Obviously this starts by cracking open the dead device and verifying that the culprit is the power supply. [Alan] then removes that board from the chassis and gets down to work with a visual inspection. He’s got several images which illustrate things to look for; blistered electrolytic capacitors, cracked solder joins, scorch marks, etc. In his case there’s obviously a burnt out fuse, but that merely protects the hardware from further damage, it’s not the cause. Next he examines the diodes of the bridge rectifier. These need to be removed from the system to do so, which he accomplishes by clipping one end of each as seen above. He found that two diodes on one side of the bridge had broken down. After replacing them he tries a new fuse which immediately burns out. But a quick swap of the capacitors and he gets the thing back up and running.

We perk up every time we see this type of repair hack. We figure if we can build our own hobby electronics we should be able to fix the cheap devices like this one.

Epson projector LED mod

Epson-projector-LED-mod

Projector bulbs can be incredibly expensive to replace. Sometimes it’s more cost efficient to just buy a whole new projector instead of a new bulb. [Shawn] recently found a nice deal on an ‘as is’ Epson EMP-S4 on eBay and decided to take a chance. He assumed it probably worked with the exception of the missing lamp the seller mentioned. His suspicions were correct, and one custom LED mod later, his projector was up and rolling.

Without a stock lamp installed, the projector would give an error message and shut itself off. So, the first step was to wire up a little bypass. Once that was taken care of, [Shawn] installed a 30W 2000 lumen LED and custom fit an old Pentium CPU heatsink to keep the LEDs temperature down. He also wired up the heatsink fan in parallel with the stock exhaust fan for good measure.  Optical lenses help focus the light, and some custom wiring makes the LED turn on and off just like the stock lamp would.

In the end, his first experiment was a success, but [Shawn] wants to try an 8000 lumen 100W LED to make it about as bright as the stock lamp was. Check out a little video walkthrough after the break.

[Thanks Shawn]

[Read more...]

Heat your house with propane (but not in the way you’re thinking)

geothermal-heat-pump-charged-with-propane

[Ralph Doncaster] has a geothermal heat pump which is responsible for providing heat for his home. He’s been looking into some hacks that would make it more efficient and decided that the freon (R-22) needed to be tweaked. Some would say the stuff is bad for the environment, so he decided to go a different route. He replaced the Freon with propane, using this rig to make the fuel-grade propane more like cooling-grade propane called r-290.

He purchased the gauge set which is used whenever a technician services an A/C system (but you can also see it in this other A/C propane hack). That’s important because it’s responsible for making sure the old coolant is recaptured (his hose failure nixed this part of the plan) and the new coolant goes where it should at the correct pressure. But before dumping in propane from the local hardware store he needs to dry it out. Fuel-grade propane can have moisture in it, which can be bad for the cooling system. He bought a drier device, the grey bulb seen above, and soldered it on one end to a propane torch fitting and to a valve connection on the other. Now he could remove moisture as he pressurized the system.

Everything is working again, and the cooling side of the system gets much colder. He plans to do more testing as time goes by.