Monday, October 29, 2007

Using LED's

I’ve been playing around with LED lighting for years now, getting hold of non-working flash lights, removing the LED’s and using them in a variety of applications. The most common application has been with motion-sensing night-lights. I remove the incandescent bulb and replace it with several LED’s inside a reflctor. I also use NiCad or lithium batteries as the power source.

These days, one can buy LED motion-sensing night-lights, but these use conventional alkaline batteries, such as the Globe LED Motion Activated Locker Light. The cheapest I’ve seen so far are sold at CVS pharmacy for about $7.50. What I do with these lights is that I remove all of the connectors for the batteries, cut out a slot in the top of the battery compartment, and place a couple of flat strips to connect a lithium battery whose dimension is around 47 x 33 x 8 mm. This replaces the three AAA batteries and lasts a lot longer.

Another use I’ve had with LED’s is with the 110v screw-in light bulb replacement. However, these seem to be rather unreliable due to thermal runaway as each LED is wired in series without any current limiter. I’ve actually broken down some of these and re-built them using a plastic funnel and old screw bases. Using my own bridge rectifier and smoothing capacitor helps a little as well as placing two bulbs in series yielding some 60 LED’s is better than a single light with 30 LED’s, a limiting capacitor in series and no smoothing electrolytic capacitor. It’s easy to use two bulbs in series within a couple of hurricane lights that normally use two conventional incandescent lights. This setup uses just over 4 watts of power per lamp, instead of some 60 watts, or 25 watts using florescent lights.

I’ve also placed 5 sets of LED lights within a low level outside wall with each set comprising 4 LED’s in series triggered by a motion sensor and a 12-volt line that is solar powered.

Here's an interesting site that shows how to replace the lithium batteries in a laptop battery pack, something I've done several times.

I've always had an interest in steam locomotives, here is GWR 6024 at Abergavenny.



Monday, October 15, 2007

A La Carte TV?

This topic is an update to one I created a few months ago on a different journal.

I’ve made the decision to cancel my cable TV service because there are too many ads which are too loud, there’s too much paid programming, I can’t select specific channels (a la carte cable) and what I have is very poor variety and quality entertainment—even from over 100 channels!

It seems that an hour of television can carry about twenty minutes or more of commercials. Add on this all those Paid Programming sessions and I’m paying $75 a month to essentially have ads thrown at me. Considering that cable providers interject local ads, I figure that they must be making more than the oil companies.

I plan to make better use of my time and if I want to watch the News, a movie or a documentary, there are plenty of Internet videos to choose from. I’ve noticed that there are a lot of web sites providing World-wide streaming of TV and Radio stations. However, I’m not comfortable with sites that charge a one-time fee as I’ve noticed that they don’t list any channels.

C-Span, Fox News, CNN, BBC and ITV all have a decent amount of news clips. I’ve also been playing with Live-TV and Miro that offers some interesting and easy ways to view video.

Although I have a small Zen Portable Video Player (PVP), it does not have a video-out socket. Rather than continually transferring video through a PVP, I've bought some modern refurbished laptops for $400 each so that I can store and play programs and movies on a TV (using S-Video)--such as this:

The Laptops are Compaq Notebook C500 types and connected wirelessly within a home network.

I've spent a fair amount of time playing with receiving local TV transmissions and I'm amazed at the number of additional channels I can receive with a digital signal. I've placed a simple 7.25-inch ring antenna in the attic, together with a 15Db amplifier (powered by the 12-volt solar/battery line that runs the length of the attic) to supply 4 HDTV's via a 4-way splitter.

I've also discovered a neat program called VEOH which allows me to view and/or store video. The nice thing about this program is that it allows me to to select from a series of videos, and it automatically plays the next in the series.

Check out Zap2it, it's a great TV listing guide.