Search found 71 matches

by Ant
Mon Nov 20, 2017 3:33 am
Forum: Lighting & Electronics
Topic: Why is my 555 timer not blinking?
Replies: 30
Views: 963

Re: Why is my 555 timer not blinking?

I can only think that perhaps the diode is polarized and that I have it in backwards. The whole point of a diode is it is polarised. it's purpose is to let current flow in one direction but not the other. It's worth doing some reading up on basic component symbols because these will always indicate...
by Ant
Thu Nov 02, 2017 3:36 am
Forum: Lighting & Electronics
Topic: PCB design
Replies: 7
Views: 396

Re: PCB design

PM'd
by Ant
Fri Oct 20, 2017 2:37 am
Forum: Lighting & Electronics
Topic: Picking a power supply
Replies: 4
Views: 191

Re: Picking a power supply

Factor a 3.2v forward voltage for the whites, with the greens it's a bit harder to guess because there are different types. Older traditional greeny-yellows have a Vf of around 2v, but more modern pure greens are more likely to be around 3v. Start with 2v and see how that looks. Assume a max operati...
by Ant
Wed Sep 13, 2017 2:21 am
Forum: Construction
Topic: Drilling Really Tiny Holes?
Replies: 8
Views: 409

Re: Drilling Really Tiny Holes?

I made myself a mini drill from a 12v motor & 600RPM gearbox combo, and miniature chuck, both from ebay for a total of less than 5 quid that I have been using with 0.5mm drills on my Zvezda SD and haven't broken a drill yet. It's fast enough to drill a hole in a couple of seconds, but not fast enoug...
by Ant
Wed Sep 13, 2017 1:59 am
Forum: Lighting & Electronics
Topic: Connecting Circuits (boards) to the same Power Supply
Replies: 2
Views: 201

Re: Connecting Circuits (boards) to the same Power Supply

Hi all! Like the title says, when connecting several different blinking circuits (boards) to the same power supply, the boards are connected in parallel - right? Right. Each module or board is a complete circuit in its own right and will have a current draw as defined by that circuit. Provided that...
by Ant
Sat Sep 02, 2017 1:50 am
Forum: Lighting & Electronics
Topic: Rotating Police Strobe Lights Effect
Replies: 15
Views: 701

Re: Rotating Police Strobe Lights Effect

I've done something like this, but will echo the comments that it is extremely fiddly!! it was only one beacon, and was driven by a microcontroller, but I did manage to get a light cluster around the size of a 5mm LED. 1st Prototypes https://vimeo.com/129956163 Final go https://vimeo.com/130010713 T...
by Ant
Thu Aug 31, 2017 11:35 am
Forum: Lighting & Electronics
Topic: Powering LEDs without resistors
Replies: 5
Views: 304

Re: Powering LEDs without resistors

I'm currently planning a project and I'm wondering, purely for ease of soldering, if I can get away with not using resistors for my LEDs. Short answer. No Long answer. LEDs are current devices. The current must be limited to specified values or the device will fail. Without any limits, the more vol...
by Ant
Wed Aug 30, 2017 2:41 am
Forum: Lighting & Electronics
Topic: 3 mm LED lights Series or Parallel
Replies: 9
Views: 439

Re: 3 mm LED lights Series or Parallel

There is absolutely no problem with using one method (series / parallel) over the other, *provided* the specification of the devices are respected. If your circuit is designed correctly, you will get a lifetime of use. LEDs just randomly failing or "burning out" under correct operational parameters ...
by Ant
Sun Aug 20, 2017 2:00 am
Forum: Lighting & Electronics
Topic: 3 mm LED lights Series or Parallel
Replies: 9
Views: 439

Re: 3 mm LED lights Series or Parallel

In series, one resistor per set of LEDs.
In parallel, one resistor for each LED.
by Ant
Tue Aug 08, 2017 2:27 am
Forum: Lighting & Electronics
Topic: LEDs & Other Low voltage, Low power lighting
Replies: 41
Views: 37865

Re: LEDs & Other Low voltage, Low power lighting

The flash rate of flashing LEDs is fixed and usually around once a second (1 Hz - Hertz is the unit of frequency. 1 Hz = 1 oscillation per second. 100Hz = 100 oscillations per second) is the 3mm to big in diameter, or too tall? If it's too tall, you might want to look at SMDs in a PLCC-2 package. Th...
by Ant
Wed Aug 02, 2017 2:09 am
Forum: Lighting & Electronics
Topic: Black Hole's V.I.N.CENT MPC model lighting kit
Replies: 2
Views: 237

Re: Black Hole's V.I.N.CENT MPC model lighting kit

Yeah that controller board looks like major overkill, although I get the impression that's just a generic driver with far greater capabilities.
by Ant
Sat Jul 15, 2017 12:00 pm
Forum: Lighting & Electronics
Topic: Source For Ultra High Quality LEDs???
Replies: 14
Views: 580

Re: Source For Ultra High Quality LEDs???

White LEDs are just blue LEDs shining on a phosphorous that emits white - there's no reason they should be any less reliable providing they are run within spec...
by Ant
Fri Jul 14, 2017 4:11 am
Forum: Lighting & Electronics
Topic: Source For Ultra High Quality LEDs???
Replies: 14
Views: 580

Re: Source For Ultra High Quality LEDs???

You will probably have to buy the LEDs yourself from a proper component supplier (not ebay) who specify what they sell, and them wire them yourself. Otherwise you're going to be at the mercy of the bottom line...
by Ant
Fri Feb 03, 2017 4:09 am
Forum: Wonderfest 2016
Topic: My photo gallery of the 2016 WonderFest
Replies: 3
Views: 2062

That Dalek shirt was the best one I saw all weekend!
by Ant
Wed Sep 28, 2016 1:49 am
Forum: Lighting & Electronics
Topic: Batteries drained in 2-3 days despite LEDs being off?
Replies: 2
Views: 843

Yes, the wireless controller will be drawing some current all the time, which will drain the batteries. Coupled with that, the CR2032 cells have very little capacity and are not intended for 'always on' circuits unless the draw is down in the micro amp range. A 9v would give you a bit longer life, b...
by Ant
Sat Sep 10, 2016 12:42 pm
Forum: Lighting & Electronics
Topic: Shouldn't 12v be enough for seven 3mm LEDs?
Replies: 31
Views: 5006

Hmm, this might suggest that the battery just not have the capacity to light them all. You could try higher resistors, this may get them all lit, but they may not be bright enough for your needs....
by Ant
Wed Sep 07, 2016 11:37 am
Forum: Lighting & Electronics
Topic: Shouldn't 12v be enough for seven 3mm LEDs?
Replies: 31
Views: 5006

Yeah by all means increase the resistance to lower the brightness to something that looks correct. The values I gave are for 20mA which is a typical LED operating current, but a higher resistance is perfectly safe - just don't use a lower resistance.
by Ant
Tue Sep 06, 2016 7:00 am
Forum: Lighting & Electronics
Topic: Shouldn't 12v be enough for seven 3mm LEDs?
Replies: 31
Views: 5006

It would be much easier if I could post some diagrams - at work at the moment so a bit difficult, but will try later. In the configuration you have, it's more likely to fail in the microseconds when power is applied, and as the diodes start to conduct and minute differences in the semiconductor prop...
by Ant
Tue Sep 06, 2016 2:33 am
Forum: Lighting & Electronics
Topic: Shouldn't 12v be enough for seven 3mm LEDs?
Replies: 31
Views: 5006

I had posted a question here about where the resistors go, and the response I got was that it does not matter where the resistors go, but that they ought to go before the LEDs. There's no ought to - it makes no functional difference whatsoever. It's just a matter of personal preference. If you real...
by Ant
Mon Sep 05, 2016 12:38 pm
Forum: Lighting & Electronics
Topic: Shouldn't 12v be enough for seven 3mm LEDs?
Replies: 31
Views: 5006

What makes all this tricky is there is no one right answer - there are a number of ways of doing it reliably (and there are a number of ways to do it wrong). The "right" way for you usually depends on a number of other factors. For me, long battery life is important, so I tend to design around lower...
by Ant
Mon Sep 05, 2016 7:14 am
Forum: Lighting & Electronics
Topic: Shouldn't 12v be enough for seven 3mm LEDs?
Replies: 31
Views: 5006

Hey Greg, Unfortunately you've not got this quite right yet :-( As far as I can tell, you're connecting each of the LEDs in parallel (all positives together, all negatives together) and then connecting that assembly in series with the resistor(s). This is a "risky" configuration which may fail at so...
by Ant
Fri Aug 26, 2016 1:09 am
Forum: Scratchbuilding
Topic: Excellent PE demo video
Replies: 3
Views: 1091

You need to take adequate care with Sodium Hydroxide when developing the photoresist. If you get it on your skin it will have a greasy feel - that's the skin dissolving!
by Ant
Sun Aug 21, 2016 12:16 pm
Forum: Lighting & Electronics
Topic: Shouldn't 12v be enough for seven 3mm LEDs?
Replies: 31
Views: 5006

Sorry, been away!
Yeah I'd go with parallel and a 4.5v battery pack.
by Ant
Thu Aug 18, 2016 2:44 pm
Forum: Lighting & Electronics
Topic: Shouldn't 12v be enough for seven 3mm LEDs?
Replies: 31
Views: 5006

LRV08 is an equivalent to A23, so you're looking at a 50mAH capacity still. Adding a second battery in series will do nothing to increase that. I'll try and explain what you are seeing in your experiments. We'll assume your particular LEDs have a forward voltage of 3.5v which is typical. This is a p...
by Ant
Thu Aug 18, 2016 1:37 am
Forum: Lighting & Electronics
Topic: Shouldn't 12v be enough for seven 3mm LEDs?
Replies: 31
Views: 5006

That's not a great article - it's written by someone learning to use LEDs but perpetuates several misconceptions, particularly the use or misuse of resistors in parallel circuits. The rule on that is simple. ALWAYS use a separate resistor with each parallel LED. IGNORE anything else you read. Not us...
by Ant
Wed Aug 17, 2016 12:36 pm
Forum: Lighting & Electronics
Topic: Shouldn't 12v be enough for seven 3mm LEDs?
Replies: 31
Views: 5006

Blue LEDs have a typical forward voltage of 3-3.5V, which means they won't be fully conducting until there is at least that potential across them. You will start to get some current flow at lower voltages - if you're getting some light with 5 but none with 6 then conduction is starting between 2v an...
by Ant
Sun Aug 14, 2016 2:08 pm
Forum: Lighting & Electronics
Topic: Powering LEDs with 3.7v Lipo
Replies: 3
Views: 1096

You need to be much more careful when using LiPos as many do not have any overcharge/overdischarge/short circuit protection built in and rely on it being provided by the circuit they are powering. At best misuse may permanently damage the cell, at worse it could catch fire or explode! Unless you are...
by Ant
Thu Aug 04, 2016 11:47 am
Forum: Lighting & Electronics
Topic: 3V LED Strip lights???
Replies: 9
Views: 4625

A "white" LED consists of very closely spaced red, blue, and green components That's true of white light from an RGB LED, but a white only LED is actually just a blue LED shining on a yellow phosphor coating which produces the white light when excited. Different phosphors are used to get cool white...
by Ant
Fri Jul 01, 2016 9:29 am
Forum: Construction
Topic: TARS/CASE in 1/72 what size?
Replies: 3
Views: 1124

TARS is basically made of 4 rectangles 68" tall, 7.5" wide and 9" deep, so just divide those by 72 to get your scale dimensions