Model Boat Mayhem

Please login or register.

Login with username, password and session length.
Pages: 1 [2]   Go Down

Author Topic: LED resistors  (Read 5147 times)

hama

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 717
  • Location: Stockholm, Sweden
Re: LED resistors
« Reply #25 on: January 05, 2021, 02:24:24 pm »

 {-) L.E.D ZEPPELIN!
Back to the subject, surely a converter will draw power and generate heat as well?
I haven't done any changes yet, but I have a adjustable DC/DC converter and new resistors of 330ohms so I have all the options.
Hama
Logged

Stan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,478
  • Location: West Yorks
Re: LED resistors
« Reply #26 on: January 05, 2021, 02:35:03 pm »

HI Hama if this was me I would fit the resistors. But because they are all the same you could use a voltage regulator instead. L E D  use very little power so I cannot imagine  the voltage regulator getting hot


Stan. :-)) :-)) :-)) :-)) :-))



 
Logged

C-3PO

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,107
  • I thought that hairy beast would be the end of me
  • Location: Outer Rim world of Tatooine
Re: LED resistors
« Reply #27 on: January 05, 2021, 02:50:53 pm »

How does a DC/DC voltage convertor control the current flow?

C-3PO


Logged
I think it's the way I have learnt most of my stuff - getting very stuck first...

Tug Fanatic

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,480
  • Location: England
Re: LED resistors
« Reply #28 on: January 05, 2021, 03:00:33 pm »

How does a DC/DC voltage convertor control the current flow?

C-3PO

Does it need to do so?

Surely it controls the voltage and then the thing on the end (in this case LED's) take as much current as they want just as they would do with a low resistance battery. If it is more than the converter can handle then the magic smoke appears. This is very unlikely unless you have an awful lot of LED's.
Logged

Plastic - RIP

  • Inactive
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,255
  • Bobbing Along!
  • Location: Watford
Re: LED resistors
« Reply #29 on: January 05, 2021, 03:05:29 pm »

HI Hama if this was me I would fit the resistors. But because they are all the same you could use a voltage regulator instead. L E D  use very little power so I cannot imagine  the voltage regulator getting hot


Stan. :-)) :-)) :-)) :-)) :-))
A voltage converter works like an ESC - it chops up the dc at a high frequency and puts it back together at a different voltage - the only heat generated is produced during the minute rise-time (the time it takes to go from off to on)  of the on/off pulses it's chopped into and as most transistors work well into the MHz, that rise time is negligible - so no heat generated.
A regulator dumps its excess power though heat - it's permanently hovering in a half on, half off mode - just like a big resistor.
Logged

Stan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,478
  • Location: West Yorks
Re: LED resistors
« Reply #30 on: January 05, 2021, 03:17:45 pm »

These are the DC voltage regulators fitted in my lobster boat supplied from Component Shop one for the pump the other for the lights. They take power straight from the drive battery the output voltage is set with the small brass screw. With the small amount of current used by the light and pump you would not expect the to get warm. The first question was why do my resistors get warm  the correct value should have been 330 ohms not 470 ohms.  Some of the answers to the initial question were just to hitec and once again I will reiterate keep it simple.
Logged

HMS Invisible

  • MICROGYROS.COM
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 517
  • Location: Paisley, Renfrewshire
    • Yes, it works!
Re: LED resistors
« Reply #31 on: January 05, 2021, 03:24:09 pm »

These are the DC voltage regulators fitted in my lobster boat supplied from Component Shop one for the pump the other for the lights. They take power straight from the drive battery the output voltage is set with the small brass screw. With the small amount of current used by the light and pump you would not expect the to get warm. The first question was why do my resistors get warm  the correct value should have been 330 ohms not 470 ohms.  Some of the answers to the initial question were just to hitec and once again I will reiterate keep it simple.
No the the initial answer was correct, Stan. He would need to stack two leds in series.
If hama changes to 330 ohm his perceived problem is worse. - More power loss.
Logged
< All manner of contact methods over to the left.

Stan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,478
  • Location: West Yorks
Re: LED resistors
« Reply #32 on: January 05, 2021, 03:32:10 pm »

HI Plastic  I have to say I have used V/ R  mainly my lighting and never had any problems with them.  Once again to much technical info that very few understand. {:-{ {:-{ {:-{ {:-{ {:-{ {:-{ {:-{ {:-{ {:-{
Logged

Stan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,478
  • Location: West Yorks
Re: LED resistors
« Reply #33 on: January 05, 2021, 03:43:49 pm »

Well all can say is this poor guy will be even more confused. All my models work fine using resistors wired I parallel. With that in mind I will leave all you techno guys to confuse him even more. {:-{ {:-{ {:-{ {:-{ {:-{
Logged

Plastic - RIP

  • Inactive
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,255
  • Bobbing Along!
  • Location: Watford
Re: LED resistors
« Reply #34 on: January 05, 2021, 04:51:41 pm »

HI Plastic  I have to say I have used V/ R  mainly my lighting and never had any problems with them.  Once again to much technical info that very few understand. {:-{ {:-{ {:-{ {:-{ {:-{ {:-{ {:-{ {:-{ {:-{
Stan, do you understand that a voltage regulator is basically a self-adjusting resistor?   It dissipates exactly the same amount of heat as the equivalent resistors would - just it's spread over a physically larger thing so the heat escapes easier so it 'feels' cooler.
Logged

Stan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,478
  • Location: West Yorks
Re: LED resistors
« Reply #35 on: January 05, 2021, 05:05:30 pm »

Thank you for that explanation in simple terms.


Stan. :-)) :-)) :-)) :-))
Logged

hama

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 717
  • Location: Stockholm, Sweden
Re: LED resistors
« Reply #36 on: January 05, 2021, 08:56:30 pm »

Hello everybody!
Thanks again for all your input, now it's up to me to handle all the information given.
I'll see how I'll proceed, but it will take some time as I'm off to work for two weeks now.
All the best!
Hama
Logged

Papa Joe

  • Shipmate
  • *
  • Offline Offline
  • Posts: 8
  • Model Boat Mayhem is Great!
  • Location: Kraaifontein Western Cape South Africa
Re: LED resistors
« Reply #37 on: January 26, 2024, 10:53:14 am »

Yeah, you're spot on about the converter. I used one for a LED project in my garage. It did heat up a bit, but as long as you keep it in a spot with good air flow, it should be fine.
Logged

chumphon

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 26
  • Model Boat Mayhem is Great!
  • Location: chumphon thailand
Re: LED resistors
« Reply #38 on: January 29, 2024, 01:40:18 pm »



You're right about the converter. I used a DC/DC converter for a LED project I did a while back. It did draw some extra power and got a bit warm, but nothing too crazy. The key is to make sure it's well ventilated. I made sure mine had enough space around it to avoid any overheating issues.

And those 330ohm resistors sound like a good choice. It's all about balancing the resistance with the LED's requirements. I had to read some reviews on leds.to and play around with a few different resistors before I found the right match for my setup.
Logged

ronnie42

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 124
  • Model Boat Mayhem is Great!
Re: LED resistors
« Reply #39 on: January 29, 2024, 03:27:35 pm »

The Germans know how to do model instructions, LED section of wiring they even give all the resistor values for all the colours.
Logged

Circlip

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 4,463
  • Location: North of Watford, South of Hadrians wall
Re: LED resistors
« Reply #40 on: January 30, 2024, 09:58:37 am »

Wow, that's typical of the type of diagram FLJ would have produced.   RIP Dave.


  Regards   Ian.
Logged
You might not like what I say, but that doesn't mean I'm wrong.
 
What I said is not what you  think you heard.
Pages: 1 [2]   Go Up
 

Page created in 0.092 seconds with 21 queries.