Progress!

Me at my new site office... across the room 🙂

I wish we were done… but I can only say that we made good progress. … and we are likely to finish just before Good Friday, and hopefully we could have a Easter Egg hunt party … 🙂 Plan is in the works. ..

Framing a partition between future bedroom and kitchen.

This is me sitting in my new “site office”… also temporary kitchen. Well at least 1 corner in my very blue future bedroom is done. Also testing the daylight LED here. Daylight looks alot better than warmwhite against this very vibrant blue wall and partition.

Oh, how do you like the white wood frame/trimmings?

At the foyer... painting station.

While I am collecting egg shells… and keeping them safe… we’ll be finishing up this partition between my future room and the kitchen.

The other completed corner is in the foyer… yes its PINK! and some Lilac white. Colors that I have done so far are Sassy (pink), Lilac white, Harmony (blue) from Nippon Easy Wash and Premium Odorless range. Yes, I painted the ceiling with this pricey paint too. I insist on good quality Nippon paint only.. Nippon should reward me for being such a good return customer since 1990.

… and yes, I use Bordelac Innosence on wood doors and Pearl Grey on railing soon to go on. Partition trimmings are coated with Timberlac white..

Technical details of flexi strip LEDs

I have written about designing LED circuits and DIY fabrication with the various components. Now that whole idea is made obsolete by the dropping cost of flexi strips LEDs. Back then, it was really not cost effective to buy a spool of flexi strip. Each 5050 LED was selling at about $1. Now, I just got some for $0.30 each and comes mounted on flexi strip complete with resisters and circuitry. Whats left to do, is to simply hook it up to a 12V power. Its that simple! Yikes!

Following my own harrowing experience on buying flexi strip LEDs, I thot I should share it with those of you who are considering to use LEDs, but are deterred by the seemingly difficult to understand technicalities.

1 strip of 5050 LEDs, cutout from a roll

Why is buying flexi strip LEDs difficult? I think the reasons are overwhelming selection, confusion over pricing, unsure of one’s needs, unsure of how to DIY install, put off by incompetant sales people and worry about being conned by installation crew.

Lets start by talking numbers. Without going into the technical nitty gritty, the visual size of each LED in a flexi strip is the best indicator of its brightness. Although they all look to be very bright, the bigger 5050 LED does shed more light and have a wider angle than the 3528 LED. These 2 types are the most common these days, but there are others that are smaller and meant for decorative purposes light christmas tree lights or car trim highlights. 

IMHO, the 5050 LED is a better all rounder than 3528 series for lighting purposes, but it is more expensive and will consume more energy while producing less light per watt when compared to 3528. Anyway, they are both better than flourescent in flicker free, power consumption and longetivity.

Large selection of flexi strip LEDs in the market. Just 3 types that I got here.

Each spool is 5meters (or 16ft) from the factory. This is complete with LEDs and resister circuitry on board the strip that no assembly or soldering is needed. When buying a strip, have the sales person open a new package, light it up and you should check that all LEDs are lighted up. If you are getting a opened package, check the 1st link and last link for the connection leads that should be sticking out from the reel. There should be 1 red and 1 black, about 10cm each at the beginning and end of the spool. If not, then you have missing links… dont buy that spool.

This picture shows 2 strips of 5050 LEDs (notice they are larger dots than the 3528). The one on top is cut from clear sleeved 30 LEDs per meter spool, and the middle is cut from a 60 LEDs per meter spool. The bottom one is 3528 LEDs from a 60LEDs per meter spool.

The next number to consider is the count of LED per meter or per spool. The usual number per meter is 30, 60, 90 and 120 SMD. SMD stands for Surface Mount Devices. The higher count means that more LEDs are packed into each metre. Normally, there are 3 SMD on each link, therefore a 30 SMD/metre strip = 3 SMD for every 10cm. … and a 120 SMD/metre strip will have 3 SMD per 2.5cm. And sure we know, the higher SMD count, the more expensive is the spool. Each SMD is a commodity, the more you get, the more you pay.

So far, I found that the prices on Amazon.com to be pretty good. I use that as a benchmark price and shop around in Sim Lim Towers. Ask around and walk away if the offered price is not good or the sales staff is lousy… I can tell you that they mostly are technical snobs, altho they might not know what differentiate they products and pricing. I did find one shop that offered a better price than Amazon for LEDs and a lousy price on power supplies to the LEDs and they did try to sell me a larger supply than was necessary… naturally, I only bought the LEDs… see, it pays to do your homework before going into the den of ……. Another personal comment, I found the pricing of old stock to be fantastic on Amazon. Like the 60SMD 3528 is going for less than local prices even after adding the shipping cost (varies a lot, depending on quantity and freight company, shopping for a freight forwarder is another subject altogether).

But really, what does more SMD per strip mean to you in terms of lighting? If the application is spot lighting, I would go for a 60SMD 5050 or 120SMD 3528 arranged in a tight square configuration. If what I wanted is to light the area on my desk, I would use 60SMD 5050 or 120 SMD 3528 running in a strip or 2 strips spaced 5-10cm apart, for almost the length of my desk. I will have to mount it under a shelf… I dun like sticking the LEDs to the ceiling for this application, I like a more table lamp kind of feel and not light up the whole room feeling.

Now, for lighting up the room with a more distributed light effect, I would use a 30 SMD 5050 or 60 SMD 3528. Well, this really depends the ambience that you want for the space. Can have a nice soothing warmwhite thats just about the right amount of brightness, or a glaring white workspace… so you will have to decide on where to place the strips to achieve the desired effect. .. and it helps to sorta have a placement and routing plan before you speak to the installation contractor. If you dont have a plan, they are going to sell you lots more LEDs, wiring and circuitry that you may never use.

Yup, you will need a “adapter” for 240V down to 12V. Nope you cant connect the LEDs to the mains. My plan is to have 1 adapter for each room. 5Amps will be plenty for a bedroom, 1 Amp will do for a loo or small storeroom.

Reno prepwork in full swing

3 weeks till moving into our new place and then starting reno while living in it. Here I am, making plans and purchases, in the hope that major reno works will be quick, such that we can settle in and do the details stuff. … things are just never as simple as I like them to be. ..

1st, I am shocked! The big apartment is supplied by a 230V 30Amps switchbox. Simply means that at any time, the power consumption in this flat is 69000W, excluding the 8.5Amps supply to the aircon. Okay, that means the aircon can draw a max of 1955Watts that is separate from the 6900W switchbox, but at 1955W the aircon is under powered. I ordered a brand new Mitsubushi inverter split 4 that is capable to produce 28,000 BTU of cooling capacity, but it will only produce 24,000 BTU because of the 8.5Amps current limit in this estate! The good is, our electric bill for aircon is capped at 8.5Amps… the bad is, our 4 rooms will take longer than usual to cool and may never be as cool as we want it to be… there are many factors to that, so we wont know until its installed and as the locals say… “see how lor”

1 strip of LEDs, cutout from a rool

What about 30Amps or 6900Watts for the other stuff? Is that enuf? … If all lights turned on (assume flourescent), thats 600W, the fridge is about 1000W during on cycle, the vacuum cleaner is another 1000W (or more), 2 x TV is another 1000W, washing machine, microwave, electric stove (2000W)… opps thats it, 6900W and there goes to circuit breaker! … alrighty, so we know to never turn on everything at once… no multitasking here.

Flexi strip LEDs in a cluster

And we really wont be using 600W for lights…. cos its only LEDs for us. These flexi-LEDs light strips are just fabulous! They have certainly come a long way. Its bright, easy to install and cheap to run. My test setup in the loo using just 2.25W is not quite enough for reading, but I would think that 4W will be enough. Thats 4W versus 11W, a energy saving of almost 70%.

A split out group of just 2 strips.

The problem of using LEDs is really the distribution of little lamps. When it is congested in a small area, the light is very focus… resulting in bright spots. So the challenge in adopting LEDs only lighting for a room is building fixtures that holds the LEDs in a manner that distributes the light best. I discovered that spliting up the LEDs into groups of 2 or 3 strips, then placing each group 1 foot away, will light up the space much better that lumping them together. However, this requires more wiring and effort for concealing the wires.

… and um…. today I placed an order for stainless steel mosaics… it has to be made and shipped from Australia… dun ask me why I did it! Its really quite expensive is it going to work out?… hope its worth it… fingers crossed.

Building your own LED light Part 2

The end product.. Looks cheap, but its made mostly with recycled stuff.

(Continue from part 1…) Sorry for the delay.. was distracted by my other project.. the Yuloh oar making and testing took more time than anticipated.

Now that the LED circuit design is done and protyping is complete with satisfactory results, its time to make the fixture. In the spirit of being “eco-minded”, I try to use as much recycled stuff as possible.

The casing

I had 2″ x 3″ pieces of clear acrylic sheets left from a previous project that I use for a window, then I cut a piece of 1/8″ ply, same size as the acrylic window. Then, prepare strips of 1/8″ x 1″ corrogated plastic sheet for the edging and have some vinyl stickers handy by. ..

Or you might wanna use a casing from a old light fixture.. its easier.. 🙂

Layout plan using prefabricated PCB

Building the circuit

My placement differs from the diagram.

Here, I am using general purpose PCB board to build this circuit. 1st, plan the layout. My target board size (constrained by the 2″x 3″ window) is 1.5″ x 2.5″. Place the components on the board, arrange it as shown here. You can have your own placement ideas, just follow the design concept that I wrote about in part one, and keep in mind these 2 things below:

Look inside the lens. Supply positive to the smaller surface.

1) LEDs do have polarity. If you got it wrong, the LED could burn… so try to be careful about the placement. Inside the clear LED lens is a big plate and a small plate. The small plate should always be more positive than the big plate.

Pre-fab PCB board.

2).Lines on the PCB board are copper under green PVC preservative film and the bronze dots with holes in the middles are for pins of the component to stick thru and for soldering contact to the underlying copper strips. The lines on my layout plan correspond to these copper strips on the PCB. When making your layout plan, take these strips into consideration, like I did.

some electrical toos.

To successfully build this PCB, you will need some skills with soldering and have a few basic tools for cutting the board, trimming the leads… etc.

LED lightup testing. It works. Pretty nice huh.

LED light boxed up.

After soldering in the components, test it. Make sure it lights up before boxing it up.

And here is the box, all built up. On hindsight, I realize that I should have taken pictures of the box building … but was too eager to finish..

Building your own LED lighting part 1

I have been fascinated by LED lights since my 1st contact with them 20 years ago, mainly the small greenish light on the computer casing that indicates power on and another for HD spinning… 🙂 These little lights have been serving that application so well, that its still being used.

Calliste head illuminated by forty-eight LEDs

But they have certainly come a long way since its invention. The radical changes to its brightness and colors in the past 10 years, made it useable in many more applications like traffic lights, flashing signages, decorative lighting, automotive lighting, etc … Most interesting to me, small space lighting.. because the common LED light is very narrowly focused, it does not diffuse well for lighting a room, but new LED lights are being introduced at a very fast rate and soon it will be possible for the indoor room lighting that is affordable to most people. I mean.. now it is available, but not that affordable to most. .. and me.. I refuse to afford 1 sensibulb for US$40. Maybe there will come a time when the price will drop to $10.. but in the meantime, using all my education and experimental skills, I am building my own LED cabin lights for Eleanor.. and maybe Calliste, if Doug approves.. 

I am also hoping that my blogging about it will help fellow sailors switch to these “Amp pinchers”.. .. its really quite cheap if you know how to build it yourself.

LED electric 101

Quick and easy way of trying out my designs.

I classify common LED as 1) between $0.10 to $0.50 ea. 2) available in small quantities (< 1000 pieces). 3) operates at voltage and current range of 2.5-3.5V, 5-100mA.

This picture shows my testing setup. The board with holes is commonly known here as the “breadboard”.. not sure how it got its name.. It is the greatest tool in my electric work kit. Just plug in the resistors and LEDs, and only 2 jumpers in my 1st setup. If you buy this board, read the instruction on how to use it properly.

12V LED circuit. These values are calculated. Real circuit values will differ due to operating tolerance of each component.

Here, I am trying to build a cabin reading light on Eleanor. This light fixture will be connected to a 12V battery. Using this 12V input, I want to generate the optimum amount of reading light with the least energy consumption. The question is, how many LEDs do I need and what current do I supply to the circuit to produce the light that I want?

I start out by testing a series 4 LED setup for 12V and supplying 20mA. The series 4 LED setup is the most efficient for 12V as each LED will be supplied with the optimum 3V voltage (as spec’ed), and the V drop across the resistor is a minimal 0.2V. Since this test is only 1 row of series 4 LED and my target current is 20mA, I calculate the resistance for this circuit using this formula: R= V/ I(target) -> R = 12/ 0.02 -> R = 600 Ohms. The result from this test gives me a initial feel of the brightness of 1 row 4 series LED. Note: 20mA = 0.02A, use 0.02A because the unit of measurement of the formula is A!

Next, I increase the target current to 50mA. Using the same formula: R= 12/0.05 -> R = 240 Ohms. I like this light color and intensity much better. Note, the optimum performance of these common LEDs is in the range of 20 to 30mA. 50mA is not the optimum, but I like it, so I use it.

Now, its a matter of increasing the number of LED rows to achieve the brightness that I want. The key here is, to increase in rows of series 4 LEDs and to adjust the resistance for maintaining 50mA. For adding rows, I apply the principle of current divider in this circuit. To supply 50mA to each row, that means total current across the resistor should be (number of rows) x 50mA. For example, 4 rows  series 4(thats 16 LEDs in total) at 50mA each, total current will be 4 x 0.05A, = 0.2A. To supply 0.2A across the resistor, R= 12/0.2 -> 60 Ohms.

Get the picture? Use this sequence of thinking. 1) What is the supply voltage? 2) How many LEDs will the supply voltage support in 1 row? 3) Determine much current to supply and how many rows is needed to get your desired brightness.

Alright, I am satisfied with the 4 rows series 4 setup. Now I am ready to make this fixture. I will post the making of the light fixture later.

How does this LED light compare to other lighting options? Lets see. A 9W flourescent draws 0.8A and produces 400 lumens. My setup here draws 0.2A and produces 128 lumens(estimate from 16 x 8lumens specified in spec). The 9W light fills the cabin better, but the LEDs is a great flicker free reading light for a small area and it uses 1/4 of the current for the 9W light. I would probably be able to light the cabin effectively using 4 LED light fixtures because it produces a 512 lumens brightness in total, but it should be distributed to be effectively. I mean, if all 4 LEDs are mounted together in 1 spot, the light is very bright and focused on 1 area. I find that it is more effective to mount them separately. .. Will show how its setup on Eleanor .. later.. when I finish.. see, I am just posting after every stage of my testing here..