Novice, seeking general advice for custom workdesk LED lamp project (24V) - Page 1
Forum section: electronics / projects

author: Decoman
author_rank: Regular Contributor
timestamp: October 22, 2019, 02:38:58 pm
content: I looked into the specs of some component I had previously considered for my custom LED lamp project, stuff being sold by the same company that is selling the particular LED strip I want, so I thought I'd buy most of my component there, but things got complicated and I lost a proper overview of things. Perhaps you guys can bring some clarity to it all.Project idea began seeing this other guy simply having this bent metal list across his work area, and gluing on an LED strip on the underside of the metal arc. I thought I could both do better, but also wanting a cover for the LED light, to diffuse the light.I have uploaded two photos shown at the very bottom of this post (!)Project description:Custom made LED table lamp, a 1,9 m wide aluminium profile w. cover, with a 24V LED "tunable white" strip inside. Single pole power (+ & -) connection via two thin steel rods on either side of the table. Powered by some kind of LED driver. An unresolved mess with buttons, connections and functionality.Electrical components:24V Tunable white LED strip (5m)24V power supply to be decidedpower potentiometer I guess (must not be noisy)visible buttons, switches or knobs that are easy to reach and not hidden under some panel or anythingtwo conductive 1m steel rodsconductive steel fastenerssuitable insulated wiringhttps://www.ledrise.eu/led-strips-modules/tunable-white-96-110w-1396lm-m-nichia-performer-led-strip-140-nichia-leds-m-24v-price-5-meters.html(fairly expensive, but I like it if only I fully understood its features)Power socket at home: 230V, 50Hz (400V into house)Desired functionality:on/off (button ideally)brightness adjustment (knob ideally)tunable white (knob ideally, otherwise unknown feature) (presumably subtle change of hue, white only)dim 2 warm (unknown feature, maybe just strong yellow)Other functionality (trivial):Rotate LED profileSafety aspect:Would such a lamp be safe for pets, kids and no risk of predictable freak accidents involving electrocution? (assuming ofc everything to be insulated is properly insulated)The motivation for this project is getting to have a nicely lit working space. And being able adjust the brightness, and keeping the LED strip 1m above the table surface, I am confident that I won't be sweating under an overly bright light. Presumably the LED strip won't be buzzing or anthing either. Another fun aspect to this lamp, is the ability to tweak the white light, into a warm light, for evenings, even though, yellowish light probably isn't the best type of working light.Various components that I don't fully understand:Potentiometer, seems rated too low, only 0,5 Ahttps://www.ledrise.eu/led-drivers-transformers-and-accesories/dimmer-potentiometer-17mm-100-kohm-sku-95181.htmlController, medium sized, also expensive:https://www.ledrise.eu/led-drivers-transformers-and-accesories/powercontroller-v2-control-unit-sku-32118.html24V LED Driver, but maybe rated for outdoor usage and high power, maybe overkill, also expensive:https://www.ledrise.eu/led-drivers-transformers-and-accesories/constant-voltage-power-supply-mean-well-npf-120d-24-ip67-230v-to-24v-5a-120w-sku-95315.htmlMini controller, w. knob and "hidden" jumper toggling two light modes (tunable white vs dim-2-warm): "https://www.ledrise.eu/led-drivers-transformers-and-accesories/tunable-white-mini-power-control-unit-dimming-and-special-mode-sku-51162.htmlUh, so regarding power potentiometer, I guess 0.5A is too low rating for the suggested potentiometer, if a 1,9 m long LED strip using ca 18,24+ watts. So 18,24 / 24V = 0,76 amps. Manual for LED suggest nearly double wattage, if using both LED diodes (the seem to come in pairs on the LED strip, different hues I guess), which would make for 36,48 watts /24V = 1,52 amps. How to make both LED SMD's shine I wouldn't know, or why it would be a good idea even.What I can't seem to wrap my head around, is how to arrange the whole thing with the buttons I want. I don't expect you guys to solve this for me, but maybe some of this is familiar to somebody here on the forums that can maybe help me out figuring out how this works. I suspect that the other stuff other than the LED's are more for housing lighting, and not custom lamps, but I thought I would try make this work, also no rush.Although that mini controller would actually fit inside the LED profile together with the LED strip further down the profile, it doesn't seem like the controller is offering controls that are all visible. According to an email from the company, a button/switch can be added to the printed circuit of the mini controller (already has a turning knob on it that can extend out from the lamp cover and being easily reachable) for "It has a push button with 3 functions that are selected via a jumper (see page six): Dim2warm, color change, dimming." It is explained that one holds the button, to dim the light, this seems unsatisfactory to me, if the light is too strong, and a turnable knob seems more intuitive. Though it should be said that the mini controller remembers the brightness level, and color hue after being turned off, so maybe not a big deal with a single button controlling this. Having a hidden jumper, seems woefully impractical if hidden behind a LED profile cover inside the lamp. :| The other controller unit might be more desirable, as it offers various buttons to be attached, however, the controller won't fit inside the LED profile/cover, and so, I imagine it might be impractical having buttons on the lamp itself, if having to have wires going back and forth a long way from the lamp and in under where this larger controller would be fixed, like under the table or something. Hm, half the charm now would be to use the two metal rods for powering the whole thing, without additional wiring outside the lamp, but that would require having buttons on the lamp itself, so that basically conflicts with having an external controller that otherwise had to be wired up into the lamp in addition to the metal rods powering the whole thing.

author: tmadness
author_rank: Regular Contributor
timestamp: October 22, 2019, 05:29:11 pm
content: Just before anyone else comes screaming at you, publish your schematic, just a rough drawn wiring/schematic diagram of how you plan to achieve what you want. It just helps everyone here if you do.Your choice of controllers are very very overkill even the mid grade option. your leds @ 5m will draw 48W with all colors lit, according to the link you have provided. so a 200w controller will accommodate 4X what you want.maybe something like this is more suited for your project:https://www.aliexpress.com/item/32792842998.htmlit has wifi and you can find something similar that can satisfy your needs for a lot cheaper.

author: Audioguru again
author_rank: Regular Contributor
timestamp: October 22, 2019, 05:42:32 pm
content: For a simple table lamp, the vast amount of parts, the high complexity and high cost seem to be too much.Why do you need to change the color from warm (pink) white to blueish "daylight"? Will you ever try mixing the two colors?

author: Decoman
author_rank: Regular Contributor
timestamp: October 23, 2019, 11:31:31 am
content: I have looked at the pdf files that the seller have on the LED strip and the mini controller, and that seem to bring some clarity, but some issues arise.@Audioguru againYes, I am fairly certain I will make use of the color changing feature of this LED. What I don't know for sure, is if I will like it or not, but at least I get to tune both the brightness AND color, at the push of a button, being a toggle. What I am trying to find out, is if I can get to easily adjust all these things without opening the lamp cover, would be nice if there were buttons or knows accessible to the user right outside the lamp within arms reach.@tmadnessI will see what I can do about making a schematic soon. (Sketch uploaded below) Btw, I only need about 1.9 meters of LED strip, not the whole 5 meters. I detest wifi, but I could accept an infrared controller. I also don't have a modern mobile phone to control stuff with. A set of buttons and knobs/dials would be idea imo.What I learned:The LED strip:2000 --> 6500K (color change)dimmable from 100% --> 0%2A max powermax 48W effect for the whole strip of 5m, 9,6W/m, or about 18W for 1,9minstallation of LED requires soldering on the three wires at one end of the LED stripseller writes "Tunable white is change of color temperature at 100% brightness"The mini controller:(I thought this had an optional push button, but it seems now that the "turn knob" on the device is just a push button, so there is no turn knob on the mini controller as I initially thought:Has one button, with three modes, controlled by a hidden jumper: 1) toggle BETWEEN preset cool white + bright light AND preset warm white + reduced brightness 2) adjust brightness 3) adjust colorcontact holes on mini controller on both ends fits AWG 22-26 wiresfed with+&-supply voltage, two wiresoutputs+&WW(warm white?) &W(white?)default installation, appear to have a three pin jumper hidden in lamp, and potentially one push button that could be extended outside the lamp cover to become easily accessible.functionality seems limited to pressing the one button, and also by moving the jumper around, pressing the same button to set max values for its dim2warm function, specifically brightness and color, the button push enabled the dim2warm function BUt also requires the jumper to be set that way as well. Seems like suitable for a set-once type of lighting, with a one button cool white/warm white toggle. I would want to figure out if I can add some controls on top of this that is accessible through the lamp cover.Manual says "maintaining mains reversal" I don't know what that means, so maybe device is not acting like a diode? I thoguth I had learned that diodes only works with the electricity going one way.Max 2,5A per channelMax 75W, at 30VOutputs voltage from 12-30VInput voltage from 12-30V, depends on LED to be usedcustomer support acknowledged to me now that this mini controller canont both dim the LEDs and also enable the dim2warm function, so it only does 1 of three modes depending on what position the jumper is setAluminium profile w. plastic transluscent cover:3cm diameter, circular in cross section, part alu profile, part plastic cover. Space for 11 mm wide LED strip.Goals:Having a nice LED desk lamp, that has tweakable controls accessible at the outside of the white lamp cover. The powersupply can be under the desk. I think I know how I could rig this all up to get the lights going, but it is still a mystery how to get to have buttons, dials or turn knobs for tweaking: on/off button, dimming knob (can't be a toggle), color change knob/button (I can accept a toggle for the color, between a cool white and warm white)Safety aspect:I also want your feedback on this issue. Supposedly, this lamp would have fixtures and a 1m long metal rod on each side that is to conduct the power from the power supply up to the lamp standing 1m above the desk surface. Would a 1m steel or brass rod really conduct electricity? Or, is maybe there supposed to be a hidden wire there at the center. I thought the rods were solid, but maybe I am wrong abou that. I guess I can try check if that is the case.Would be nice if I could maybe have the mini controller and the LED strip connected in a serie on the alu profile, and then maybe add a turn knob for generall dimming on the lamp BEFORE the mini controller if that is possible. Optionally also, an on/off button BEFORE the mini controller. An accessible dimmer is a must, as I don't want to risk start sweating with this LED lamp some 40cm above my head at the desk.Here are links to product pdf files from seller if you trust opening such files in these days:LED strip:https://www.ledrise.eu/amfile/file/download/file_id/26051/product_id/1144/(From:https://www.ledrise.eu/led-strips-modules/tunable-white-96-110w-1396lm-m-nichia-performer-led-strip-140-nichia-leds-m-24v-price-5-meters.html)Mini controller:https://www.ledrise.eu/amfile/file/download/file_id/26939/product_id/1028/(From:https://www.ledrise.eu/led-drivers-transformers-and-accesories/tunable-white-mini-power-control-unit-dimming-and-special-mode-sku-51162.html)Q: I wonder if I could maybe have two mini controllers in a serie before the LED strip. Then, I would at least get to have one additional push button. Unsure if that would simply work. Button #1 (toggle cool vs warm light Button) #2 (dim light by keep pressing the button down).Update:I have sent an email to the seller asking if I can set up two controllers this way, one button for toggle color, and one button for adjusting brightness.Update:Hm, I guess it would make sense that (ref images below) the "W" connection on the LED strip is for brightness only. WW being connection for light color. OR.. one connection goes to one of the two LEDs (paired) and the other one goes to the other LED (same pair).Update:Maybe the best location to add a turn knob for "brightness" could be right before the LED strip, connecting that to the "W" connection (presumalbly for brightness). That way I could use only one mini controller to set a permanent color toggle (button). Having this other added turn knob for brightness. And then, maybe an on/off button at the very start of the series of components here inside the lamp (I could drill a hole in the plastic cover, to access on/off switch AND the mini controller button AND the turn knob for brightness.Update:I added a third drawing, showing only one mini controller for setting a fixed toggle for color, and adding a potentiometer just before the LED strip to control brightness (I guess, it would only control the cool white LED, and perhaps not both LEDs in the pairs)Update: I guess what I have drawn on my drawing, is a rheostat, with two connections and not a regular potentiometer. But maybe a pot can be used as a rheostat?Although the manual says that both led's can be on 100% (double the wattage for nearly a 19W in total per meter, don't know that that is enabled), I don't know if both LEDs in the pairs, are supposed to be on regardless of color temperature chosen. Presumably cool white would have the darker and more yellow in the pair light up with less or no power. I wish I knew more about this. I guess I can ask the seller again, if they aren't tired of my emails by now.Added:I have at least a candidate for a dimmer, rated 5A, which should be well enough, expecting no more than some 40W tops (ca 1,7A). Hm, can't have that thing dangling around, must be placed in a box then, if added as suggested by seller, after the powersupply, near the desk surface somewhere. I guess encasing plastic ought not be flammable styrene (something I could make), or maybe that doesn't matter too much.Presumably material choice matters, to make it robust, and perhaps non-flammable, not sure.https://www.ledrise.eu/led-drivers-transformers-and-accesories/led-dimmer-pwm-v2-12-24vdc-max-5a-sku-50975-01.html