Info Manual: constant current driver

Showing posts with label constant current driver. Show all posts

Tuesday, October 20, 2015

Led Brake Light

Constant current LED brake light tail light module. Ever wonder how to make your filament bulb type tail / brake light to all leds, the solution is to use a constant current led driver with additional mosfet as switch for brake light so that the usual tail light will switch from dimmed to full brightness on the leds. More often, enthusiast uses just again the limiting resistor type of controlling the brightness of the light emitting diode installed on the bike, as i had said from all of my previous post about led, in order for them to stay consistent and works longer, a constant current driver will protect your led installed.

COB, (Chips on Board) , multi LED (light emitting diode)chips are packaged together as one lighting module. When it light up, it looks like a lighting panel. COB LED is multi chips packaged, it can 10 times more increase lighting area,so it avoid uncomfortable glare by the maximum extent.By now, for small size chip, some famous LED chip manufacturer can reach 249lm/watt @ 20mA. But big size LED chip can only reach 161lm/watt @350mA.The light efficacy decrease when chip size is bigger. Also when LED driver increase current to LED, the light efficacy per watt is even low.COB technology provides significant advantages over surface mount technology (SMT) components in the design with better temperature management, smaller size of lumen packages and lower production costs. In general the life span of COB LED can be 40000-50000 hours.

COB led as shown above compose of seven (7) led in series and requires again a constant current driver, from tha specification found all over the net requires 12v driving them at 300mah of current.From the previous page that can be found here PROJECT LED HEADLIGHT . I still use the same DIY led driver so that the voltage of the led in series will float depending on the forward voltage of each led and the current to the led will then remain constant.

Actually, there are so many led driver being offered all over the net, i myself wanted to have one of them at least, but due to lack of resources, i just make my own out from those datasheet of every semiconductor that performs the same function for led lighting. And from the schematic, will make PCB for those components to make the circuit work. Pre testing is required not to waste every component.

Schematic of the led driver can be found here led boost constant current driver . For Pcb, you really have to make it on your own since i am just making mine using pen. But to make it easier, there are lots of downloadable PCB software available for all of you to test.

COB led connected to the led current driver (sorry for the photo, grayscale color :(

Beam shot was taken at a 90 degrees, note that the surrounding do not have any other lights on, only the COB led itself..hmmm too powerful for me, wide beam actually cover lots of area than my previous attempt using seven (7) x 3 watts power led in series.

Shot taken now at 45 degree from the actual beamshot, too much glare is obvious, (disclaimer), when doing such experiments on high power leds, avoid prolong exposure of the eye to the actual beam, you may temporary have a blur vision after, and may cause eye disorder.

Actual beamshot towards the floor at my garage, very interesting that due to the wide cover area of the led the beamshot was as if i am using a CCFL energy saving lamp, so that is why manufacturers use it for household lighting. :)

Universal led DVD laser driver

DVD laser pick up hack can be found all over the internet, others use the linear type laser driver that uses LM317 as the regulator for the laser. Actually laser is also a type of diode that emits light and with the use of a focus lens, we can attain just a dot for it to be called a pointing light device.

Shown on the left was the constant current driver on my previous post about led driver. This Buck converter can supply up to 700 mah constant current to a high power led of 3 watts. The heart of the circuit was NCP3063 made by On semiconductor.

I made two of them one will drive the high power led and the other will drive the DVD laser for this hack.

Since theres no documentation of the maximal current a DVD laser must have, I made one with a 1.5 ohms sense resistor, and the other with 1.8 ohms, both differ with current that will provide to the led.

The forward voltage of the led will just float when the CC driver is connected to the load.

R203 and R202 will determine the current output of this driver. It is very important to calculate it for your led, if you know the specification of your high power led.

NOTE: never power up the CC driver without load. the NCP3063 will be damaged.

The test show a 3 watts cool white led connected and the CC driver is powered by a 12 volts AC adaptor.

The actual current being supplied to the led is actually 370mah..(forgot to take picture with a ammeter connected in series with the load..next time :)....)

With the same LED CC driver, a blue high power led is connected as shown below.

The led being tested here actually have different forward voltage drop and according to their datasheet.

and now to test if this led CC driver will power up the DVD laser,

cool yes it can be powered by this driver. I am thinking of the LM317 before but i wanted it to have a wide input voltage range.

shown below is the test, inside the black tube was the dvd laser

I know many of you wondering what's inside a household led lighting such as this one shown on the photo. A 5 watts led light with E27 type socket, same as those CCFL energy saving lamp. They are commonly been found nationwide on hardware store, supermarket and electronic supplies at an affordable price. Being an enthusiast and a DIY'er, i got curious again what was inside this kind of household lighting. I recently bought one for another experimentation and wanted to take a peek inside.

By twisting the diffuser, at last the leds came out and i wasn't surprised at all. 5 pieces of 1 watt led was used to bring out the 5 watts specification of this led lighting. They were soldered on an aluminum piece of PCB, to where they will act as the minimum heatsink, and the violet (purple) fins as the main thermal support for the assembly. Getting deeper onto it, i desoldered the board to the main heatsink and

Info Manual

Tuesday, October 20, 2015

Led Brake Light

Driving COB Led

Universal led DVD laser driver

Inside E27 5 Watts Led