Re: LED Resistor Calculations ...
I suppose I could just put a buck converter on there and drop the voltage or find some surface mount resistors and replace them.
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Re: LED Resistor Calculations ...
got a link to the leds?
i get 6.6ohm for 3v and 150maLeave a comment:
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LED Resistor Calculations ...
So I ordered a few PCBs from JLPCB ... among them, is an LED panel I've wanted for a while ... this is what it ended up looking like:
And I mean ... $25 for 10 of them with all the parts installed by them ... how stupid cheap is that? Total no brainer ... but to chose the resistor for each line of LEDs I used an online calculator. I speced the LEDs at 3.0 volts, 150ma with a 19v power supply and this is the design it kicked out with 6.8Ohm resistors. I believe it called for ΒΌ watt, but I got Β½ watt.
Anyways, as I was looking at the actual specs for the LEDs, they are rated at like 2.8 to 3.4 volts ... so I decided to go back to that web site and re-run the calls with the LEDs speced at 3.4 with everything else staying the same. And what it kicked back was kind of interesting to me ... it speced 15 ohm resistors for each line instead of the 6.8 ... and with the 15 ohm resistors it said the circuit would draw a total of 900ma ... but only 750ma with the LEDs speced at 3.0 volts.
Now see this is interesting to me, because since the LEDs have a voltage rating that is a range of voltage, and since they are capable of running at 3.4 volts, does that mean I'll be over-driving them with the 6.8 ohm resistors?
How does that work?
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Dear community, I want to increase the lifespan of my backlight led in my TV by decreasing the current.
However I need some help identifying the resistor I need to replace to achieve this.
Thank you!
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Hey everyone,
I'm currently working on a mid-70s Sharp Electronic Digital Clock Radio, Model FY-70CH. I found the service manual online, printed it out, and have been studying it for a while. My main reasons for tackling this are: (1) I want to learn electronics and figured I'd start with something I had on hand, and (2) I want to fix its issues. Right now, the radio sounds awful, has about 5V DC at the speaker terminals, and the alarm time setting doesn't work. But I'm not asking how to fix these problems.
Instead, here's what's been bugging me so far:
The schematic... -
The resistor on this waterpik blew. I changed it with the a similar spec 47ohm 2 watt yageo resistor but it still keeps blowing the resistor. Checking with the multimeter the motor, capacitor, diodes, and thermal fuse all checked normal. Will a higher ohm resistor work better? What ohm resistor will work better to repair this waterpik? This video is showing the repair with a 56 ohm resistor https://www.youtube.com/watch?v=_J7_rV7ui1Y -
Hi there !
I'm having an issue for several weeks with my quite old K70 LUX RGB keyboard. I haven't used it for few months, and once I setup up again my desktop computer, I got several dead LEDs on that keyboard. I tried the Corsair troubleshooting thing (disabling options in iCUE, ...) but nothing changed so I conclude that for some reason some LEDs went in retirement...π
Decision taken to change these LEDs as I have access to desoldering iron and binocular magnifier, I wrote a ticket to tech support, hopping to obtain the LEDs reference and... They refused to tell me π...10-08-2024, 11:58 AM -
I have purchased an 100-240v AC/5v 2a DC adaptor from aliexpress,and a month ago It smelled burning when I plugin it powerstrip.
Since then, This AC/DC adaptor have been out of order.
But A few days ago,I replace 0.5 watt resistor with 1 watt resistor(1ohm) in this adapter.
After replacing resistor,It succeed to recharge all of android phone.And When I measure voltage on the two pins of USB port,It shows 5.5v
Is it okay to replace 1/2 watt resistor with 1 watt resistor in AC/DC adapter?
And Is there any possibility that it will suddenly explode as well as to be out...
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