Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [cob]

23 questions
10
votes
2 answers

How to manufacture chip on board?

I am a developer of a cheap product and i have no experience in mass production. Device is fully functional and represents a single sided PCB, a microcontroller, a bunch of diodes and a few passive elements. However, MC is kinda overkill and…
Sergio
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4
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3 answers

What is the best way to avoid the voltage drop with a diode in this situation?

Here is essentially the schematic: I have it mocked up and everything is great, bright and cool to the touch, but one LED array (COBs) is definitely dimmer than the other due to the very small voltage drop .3v across that diode. Is there a better…
Gilligan
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4
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2 answers

Relay contact insulation doesn't seem to be enough

I'm working with an ESP32 and a 4 relay module. The problem seems to be that the insulation of contacts in the relay is not enough. Relays close perfectly and my lights turn on, but when they open, a 20V or less voltage remains between the main…
Mariano Franceschetti
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4
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2 answers

LED diodes as both diode and load for boost converter

I'm doing an LED project with a 36V Cree CXB3590 COB LED that I intend to underpower to experiment with efficiency and learn about boost converter design. I've made a 5uH inductor with 14 gauge magnet wire wound onto a T50 toroidal…
K H
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3
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2 answers

ACF to mount bare die?

I've been learning about ACF for doing a chip-on-board application, but I'm having a little trouble finding enough information about it. My main questions are: How is alignment done for very fine pitch chips? Are there guidelines to follow for how…
sbell
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2
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1 answer

Silicon die on Peltier device with COB wirebonding

I have a camera sensor (bare die) that must go on a very tiny PCB that also contains electronics for data serialization that dissipate enough power to make the PCB pretty hot (40-60 deg. C). I want to keep the camera sensor cool (at least 25 deg C…
jonnew
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2
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3 answers

Do COB LEDs usually need electrically insulating from the heatsink?

I have some Vero series LEDs from Bridgelux. I want to put multiple LEDs on 1 heatsink. I was planning to use thermal epoxy, so there is the possibility of the aluminium base of the LED touching the metal heatsink. I have looked through the data…
John Spence
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1
vote
3 answers

Is this power supply suitable for powering these chip on board (COB) LEDs?

I have an LED project using 100 Citizen CLU048-1212C4 LEDs. I need to run each LED at 70W, and I want to run every 5 LEDs on 1 power supply. I was thinking of using the MEAN WELL LSR-350-35 (it takes a long time to show PDF) Video review of the…
Yousef JO
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1
vote
1 answer

COB LED Dimming via Poentiometer?

I want to create a dimmer for high power LED light's i'm building for video work. I'm using CREE CXB3590 chips, which have run at 36V with a forward current of 3.6A. I am powering these through a 150W 12V power adapter, hookued up to a step up…
Phil
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1
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2 answers

Overcurrent Protection for COB Leds wired in parallel powered by Const Voltage Mean Well Driver

Roughly this is my current wiring diagram. The Mean Well driver that I am using is the HLG-185H-36B. Output 36v DC, max current 5.2A. The Cobs are 36V and have a max operating current of 2.76A, however, I am running them at around ~1.44A (Max). …
EffOfX
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1
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3 answers

3W 12V COB LED with 12V Campervan system

I have an LED downlight in the camper we just bought but unfortunately the module inside is dead. I would like to replace it with another LED module/chip for cheap. The light we have:…
Tom
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1
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1 answer

Powering COB LED with "under-voltage" LED driver

I have LED Driver Model: LD-361500-105MPF Input: 90-260VAC 50/60Hz and Output: 20-36VDC, 1500mA+/-5%. I connected it to the LED COB Citizen 1212C4 which needs, according to datasheet (COB's datasheet link, page 6), 37V at 1500mA. When i power up…
Josip7171
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0
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1 answer

COB LED unwanted blinking

I'm testing a Cree CXB1304 powered by a constant current driver Meanwell LPV-35-36 This setup makes the LED blink regularly every 2 secs, as I've read this occurs when the driver has insufficient specs. I have a basic understanding of diodes and to…
maximg
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2 answers

How to use this solderless conector (50 Watts COB LED)?

I bought this 50 Watts 220v COB LED at Aliexpress: It's solderless. The connector is in the upper left corner, but I can't figure out how to connect the wires: must I depress or lift the tabs or just push the wire into? This is the page: 50 Watts…
Candid Moe
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0
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1 answer

Questions about COBs and power supplies from a beginner

I'm planning to use Citizen 1212 COBs, but I don't know how they can be used on 70 watt for each one of them, knowing that each unit will have 5 COBs. So my question is: what is the right power supply for me to run these on parallel? And if they…
Karim Mohamed
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