Search found 237 matches

by abenn
Sat Jun 24, 2017 7:36 pm
Forum: Electronics
Topic: Why have my green LEDs turned yellow?
Replies: 25
Views: 2600

Re: Why have my green LEDs turned yellow?

Well you had your invalid assumption, they did make a difference! As you say, you might need a blocking diode or will the simple act of powering them up prevent a current flow. They're all disconnected now, and adding a blocking diode is not going to be a big deal, so I'll do that before I connect ...
by abenn
Sat Jun 24, 2017 7:34 pm
Forum: Electronics
Topic: Why have my green LEDs turned yellow?
Replies: 25
Views: 2600

Re: Why have my green LEDs turned yellow?

Flashbang wrote:I recon they are ripening! They were green to start off, yellow as they progress and next they will fully ripen and become red! Much like Tomatoes and Peppers :D . . .
Trouble is, a few of them seem to have over-ripened already, and now need to be replaced. They're not red, just dead :lol:
by abenn
Sat Jun 24, 2017 4:47 pm
Forum: Electronics
Topic: Why have my green LEDs turned yellow?
Replies: 25
Views: 2600

Re: Why have my green LEDs turned yellow?

Problem solved! What I didn't tell you, which I'd forgotten, is that in the working panel I've added monitor circuits to the panel points LEDs so that when two sets of points are set to a valid route, then further LEDs will light up along that route. This feature was not on my prototype, and the mo...
by abenn
Sat Jun 24, 2017 3:20 pm
Forum: Electronics
Topic: Why have my green LEDs turned yellow?
Replies: 25
Views: 2600

Re: Why have my green LEDs turned yellow?

This doesn't make sense to me! One of the three LEDs that are still showing green gives me 2.08v and 9.13mA when lit; that sounds about right to me. One sample of the other 24 LEDs, that are showing yellow, gives me 4.03v and 96.8mA when lit :o Inserting a 220-ohm resistor (just a value I happened ...
by abenn
Sat Jun 24, 2017 8:46 am
Forum: Electronics
Topic: Why have my green LEDs turned yellow?
Replies: 25
Views: 2600

Re: Why have my green LEDs turned yellow?

Thanks for your comments Ironduke. So, as you've calculated, my 1.8mm LEDs are still green at 8mA (my test using 5v supply and 330 ohm resistor), so if this phenomenon is current-related it suggests that for some reason my system is delivering even less that 8mA -- which was okay when I used 3mm LED...
by abenn
Fri Jun 23, 2017 12:24 pm
Forum: Electronics
Topic: Why have my green LEDs turned yellow?
Replies: 25
Views: 2600

Re: Why have my green LEDs turned yellow?

http://docs-europe.electrocomponents.com/webdocs/14cc/0900766b814ccf4b.pdf Here's the spec sheet for the driver I'm using. I use them in many applications -- 10mA, 15mA, and 20mA versions -- instead of resistors so that my LEDs can cope with a range of voltages.
by abenn
Fri Jun 23, 2017 8:30 am
Forum: Electronics
Topic: Why have my green LEDs turned yellow?
Replies: 25
Views: 2600

Re: Why have my green LEDs turned yellow?

Yes, I'm aware of the different specs but, as I said a couple of posts back, I've checked the 1.8mm LEDs separately on 10mA and they show nice bright green. So I can only assume that something is preventing my PICAXE circuits from sending even 10mA to the LEDs. I think I'll have to experiment with o...
by abenn
Thu Jun 22, 2017 7:44 pm
Forum: Electronics
Topic: Why have my green LEDs turned yellow?
Replies: 25
Views: 2600

Re: Why have my green LEDs turned yellow?

I was thinking about a thin wash End2end, but it might be easier if I can find a way to make the few remaining green ones (I think it's only 4) yellow so that the whole panel looks the same! This afternoon I tested an new unused 1.8mm LED from the same batch as all the others, and it stays green rig...
by abenn
Thu Jun 22, 2017 9:04 am
Forum: Electronics
Topic: Why have my green LEDs turned yellow?
Replies: 25
Views: 2600

Re: Why have my green LEDs turned yellow?

Thanks for the replies. Unfortunately I didn't test all of them, just one or two, before installing. They were definitely nice emerald green then, and one or two (out of about 50) still are. And there's no hidden resistors built in. I'm using a 5v supply with an NS150010 10mA "LED driver" ...
by abenn
Wed Jun 21, 2017 8:11 pm
Forum: Electronics
Topic: Why have my green LEDs turned yellow?
Replies: 25
Views: 2600

Why have my green LEDs turned yellow?

After building a prototype using 3mm LEDs, I've just completed my final version of my points control panel (mimic diagram) using 1.8mm green LEDs to indicate which way the points are set. The prototype panel has worked fine for a year or so, so I just transferred all the switches to the new panel an...
by abenn
Fri Apr 28, 2017 8:08 pm
Forum: N Gauge Model Railway
Topic: New GF Castle class
Replies: 11
Views: 1277

Re: New GF Castle class

That's good to hear michaelasc. I think I'll re-order one of the next batch (different name/number) which is due out in June, I think, and ask them to test before sending.
by abenn
Fri Apr 28, 2017 4:21 pm
Forum: N Gauge Model Railway
Topic: New GF Castle class
Replies: 11
Views: 1277

Re: New GF Castle class

My final remark in my previous post was a bit tongue-in-cheek. But just about half an hour ago I got a phone call from Hattons to say that they've checked six other GF Castles and can't find one that doesn't make the grinding noise that I complained about :( So they're refunding my money and postage...
by abenn
Fri Apr 28, 2017 11:41 am
Forum: N Gauge Model Railway
Topic: New GF Castle class
Replies: 11
Views: 1277

Re: New GF Castle class

Sad but true. But how come sparkhill's experience with American N-gauge is better? Are they much more expensive? Before sending my second Castle back to Hattons I phoned them, and they said they would test-run the next one before sending it to me. I hope they've got enough in stock to be able to fin...
by abenn
Tue Apr 25, 2017 8:33 pm
Forum: N Gauge Model Railway
Topic: New GF Castle class
Replies: 11
Views: 1277

Re: New GF Castle class

Good news: A replacement arrived from Hattons today, and it runs without jerking :D Bad news: The replacement sounds like its gearbox is full of gravel :( It's been running for about an hour in each direction with no load, and the noise is no better, so it looks like it will have to go back again.
by abenn
Sat Apr 22, 2017 8:33 am
Forum: N Gauge Model Railway
Topic: New GF Castle class
Replies: 11
Views: 1277

New GF Castle class

I got my GF Castle class loco two days ago :D Yesterday it was on its way back to Hattons :( It ran with a rhythmic jerking motion, as if one of the gears in the drive train was slightly oval or off-centre. It seemed to improve ever so slightly after 30 minutes running-in in each direction, but with...

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