Fixing Lights with LM7800 Voltage Regulators

These LM7800 series chips are simple.

You choose the kind you want.  3, 5, 6, 9, 12 Volt Output and more.

The name corresponds to the voltage.  If you want 5 Volts DC like a USB port you need LM7805.

12 Volts like your car radio?  LM7812.

There are three pins.

Ground is the middle.  Negative wire.

The outside pins on both side?  Those are interchangeable – you choose.

  • One pin is your Positive Wire to the appliance/radio/light.
  • The other pin comes from the power supplying it.

Either AC or DC.  It doesn’t care.

Limitation is that if you want 5 Volts out, you need to feed it about 7 Volts in.  A little more in than out.  That loss is vented off as heat, so bolt it to the side of the container, preferably to metal.

Another way to describe it is that you can flip it over either way and start soldering.

Pin 1 Output Positive.

Pin 2 Ground – Negative for both Input and Output.

Pin 3 Input Positive or AC Signal.

The backstory is that there are a lot of Solar Powered LED Lights out there, as well as a lot of LED outdoor lighting.  They wear out.  Batteries last a year or two.  They get dropped and stop working like what happened with me this time.  They get hit by an errant pole or baseball.

You get the picture.

Most Low Voltage Outdoor Lighting works on 12 Volts AC.

Most LED lights work with 3 to 6 Volts DC.

I tested my light that broke, the LED still worked.  It was as bright as the “working” lights when I plugged it into USB power at 5 Volts.

That meant I could fix it with a 25 cent chip and a little time.  Those lights are about 20 to 50 dollars.  They can be more expensive.

I chose chip and time.

It all fit inside the original housing once I cut the original power regulator and removed it from the housing.  It wasn’t even glued in place.

Soldered everything in place, and I now have a light for my porch.

Easy Peasy!

Advertisements

Using Aftermarket 18650 Lithium Batteries in a Rechargeable Garden Tool

Let me start out with saying the lawyer words:

This is at your own risk.

The batteries I am using are Lithium Ion batteries scavenged from (one or more) laptops.  If you puncture, overheat, or otherwise damage one of these batteries it is possible that they may catch fire.

Do not short circuit these batteries.  Use a charger designed for these batteries specifically.

This is at your own risk.

The Science Words:

The batteries were scavenged from laptops, and you can get 18650 batteries online that will be of full capacity.  I am using scavenged batteries because I had a couple old laptops that were going to be recycled.

From what I have learned, you can not charge these Lithium batteries in series.  Connected as a block, the batteries will overheat when charged and they may catch fire.  The circuitry in a laptop will charge the individual cells separately.

They are 3.7 VDC cells, which makes them attractive for this project.  The saw took 14.4 VDC which is four cells.  I had 4 2 cell blocks which gave me more amperage to push into the saw.

I get around all the warnings doing it this way because the cells can be removed, and charged individually in a charger made for 18650 Lithium Ion batteries.

Or so it says when I bought it from a Chinese Supplier – and we all know how trustworthy Chinese Suppliers can be.

Or not.

Sarcasm aside, here’s how I did it.

I had a Saw that was given to me as an oddball item.  No battery pack, No Charger.

I had all these batteries.

I ordered the battery holder (that black thing with the blue cells in them) for emergency purposes.

Connecting four batteries gives me 14.4 VDC so I was able to test the saw by connecting the terminals directly.  The motor worked.

Waiting for a reason to heat up the hot glue gun, I decided to do this one sunday morning.  It took me about an hour.

Step 1 disassembly.

Remove all screws and set the mechanicals aside.  I was lucky that the parts did not fall out onto the table when I went to open the saw, and nothing was plastic welded together.

Luckily, the electronics were simple, and the plug into which the original battery pack was to fit was obvious.  I could slide that connector out and solder my battery pack to that connector permanently, glue the battery pack in place, and screw things back together.

The placement of the new battery pack was by eyeball, and made sense to me.  Your placement will probably vary.  See my last picture for what I’m getting at.

Step 2 solder the connection.

I realized I could thread the two wires from the battery pack through the air vents in the side of the saw without drilling holes.  Of course, if you are modifying a different tool, your placement will vary.

Using Hot Glue, I was able to attach the battery holder to the side of the saw and only covered up one of the multiple screw holes on the side.

When that was placed, then I could connect the block’s wires to the Red, Positive connector to the Saw’s Electronics with Solder.  Red-to-red – to keep the polarity of my connections correct.

I then did the same for the Black, Negative connection.  Again, Black-to-Black to keep the polarity of my connections correct.

I did a test to make sure that the wires were soldered to the connector block like in the picture above.  The motor groaned to life, the wires held, and I noted that the batteries needed a charge.

I then disconnected all of the batteries and wrangled the connector block back into place, seated the wires, and screwed the Saw back together.

Step 3 the finished product.

Once I seated the wires inside the saw back in their original channels, I could close the unit up back as normal.

After it was placed back together, I tested the saw once again and everything worked.

Great!

Step 4 Why I did it this way instead of getting a battery pack.

So yeah I could have thrown money at this saw.  The thing was that I knew that I would not need it much.  Having a lot of these batteries around, as well as the battery packs from last Hurricane Season, I knew that I could rig a lot of this sort of thing together.

I had a couple of other tools in the shed that I could have done this with, but the Saw was the only oddball that ran at 14.4VDC.  The other tools were powered by 18VDC and we had gotten a charger and a battery for them.

So my red saw being the only odd man out was going to get “hacked”.

Safety would dictate not doing it this way, but I do have the batteries, and I did have a little better than basic knowledge of electronics being able to replace individual components on an electronic appliance.

“I do board level repairs” on electronics, when they are readily apparent as to what needs to be replaced.  This kind of a mod is trivial.

It rendered it “more safe” because the batteries are taken out of the unit and charged separately.

But ultimately this kind of thing is at your own risk since it is what a pharmaceutical would call an Off Label Use of the product.

But really ….

Pebble Steel Charging Issues – Creating a Charging Ground Platform for the Pebble Watch

Recently I was bequeathed a Pebble Steel watch.  My godmother’s husband, Larry, had passed and his wife Kathie wanted to make sure that it would go to someone who would actually use it.

Thank you Kathie, and thank you for keeping Larry’s spirit alive.

The watch is a beautiful thing, after all who can pass up an E-Paper display on a watch.  For an electronic watch, it simply blows away any other display technology for sheer flexibility.  Low light, it has a backlight that gives a blue glow once you press a button.  In high light, the numbers show up in a beautiful silver on deep navy blue.  Other Pebble watches have different color schemes, but the E-Paper display is amazing.

 

The watch did not come with the charging cable, initially.  Since I was given it at Larry’s Celebration of Life ceremony, I wasn’t going to ask for it immediately.  I did get it a couple weeks later, but until then I would “find something” to make sure it still worked.

I did find a Reddit link to something someone wrote. Apparently the connectors on the watch, in my case on the side of the watch, were Negative and Positive connections with the case being an extra Negative – the Ground.  For other Pebble Watches, the connectors are on the back of the watch.

This is where I issue the Internet Standard Warning:


Contact Pebble for Service under Warranty if your watch is still warranted.  Much better than hacking around with whatever I say here!

Any information given here within is presented at your own risk.

If you use it and break anything, it is at your own responsibility, and I take no responsibility or give no warranty. 

All Information presented here within “works for me”.  

If you connect something backwards or short out a connection, you could damage any of your electronics.

Make doubly sure you have tested all connections with a multi meter and make sure that you have polarity correct.

 

First – clean all connectors.

Second – get your Pebble up to the latest firmware.


According to this link on Reddit, you will be able to fashion (jury rig) a connector to charge your watch.

I was able to.  I connected a piece of wire to the positive connector on the watch, a second to the negative, and fed 5VDC into it.  The watch vibrated almost immediately, displayed the Pebble start up display, then began charging for as long as I was able to hold all the connectors together.

For the Pebble Steel, the Positive connector is the connector closest to you, assuming you hold the watch as if it is to be read correctly.

Problem One:

Charging Problem NOT Originally solved.  You see, there’s a problem with these watches.  If you charge one up full using the cable on the connectors at the side of the watch, then reconnect it, it will discharge back into the power supply draining the watch.

They need a Diode in line to help fix that.  Ten Cent Part.

Problem Two:

The connectors must be clean.  As in no dirt on the connectors at all.  Clean with Alcohol and a bit of cotton.  This may allow you to charge the watch but not necessarily.  I tried it and it did not help.

Problem Three:

The cable finally arrived.  There was about 70% charge on the watch.  I plugged the cable into the back of my laptop, and walked away.  The watch drained completely of any power.

The Solution presented itself in a Youtube Video that is embedded below.  There is a person in Holland with a Pebble Steel watch.  He had the same problem as I did.  In the video he mentions that his watch would charge sometimes but not others.  When he asked for service from Pebble Support, he was sent back a new watch which worked perfectly under warranty.

 

Great!  Excellent service, Pebble!

Near the end of the video, he tied all the information together without knowing it for me.  He plugged the new watch onto the cable, and connected the old watch to a second cable.  The old “damaged” watch did not begin to charge until he touched the back of the old watch to the new one thereby creating the ground.


 

Therefore my solution was this.  I created a Charging Ground Platform for my Pebble Steel.

Step 1: Obtain parts:

  • Four Thumbtacks
  • Suitable base for the platform – mine was a lid to a treats canister.
  • Length of wire to connect to Ground – specific length is not material, mine is about 18 inches or a half meter
  • Good electrical ground to the negative side of the charging cable

Step 2: Assembly

  • For your watch, positioning of the thumbtacks will vary.
  • I laid a piece of paper on the back of the watch to make a template, then marked it off on the plastic lid.
  • Marks on the lid will match that of the screws on the watch.
  • This placement will lower the probability that the watch will get scratched up.
  • Drive one thumbtack through the lid for each corner of the watch.
  • Connect each thumbtack with wire allowing the wire to extend out past the last connector freely.

Step 3:  Final Connections:

 

  • Plug the Pebble charging cable into your charger and to your watch.
  • In my case, I am using a laptop and that greatly simplified my connections.
  • The case of the laptop is a ground, and functions as a ground for USB and for the entire computer.
  • An external charging “wall wart” plug will require you to take further steps.
  • Connect the ground wire from the Charging Ground Platform to a metal ground on the laptop.
  • Place the Pebble Watch onto the assembled platform making sure that one or more of the thumbtack will touch the bare metal case of the watch, preferably on the screws in the back of the watch.
  • You may or may not get confirmation from the watch that it is now charging – I have seen it immediately go into charge mode, and I have seen it not and both work.

The way I see it, in my uneducated opinion, this is a design flaw.  I do not know where the fault lies.  It is acting like a firmware issue.  However my Pebble Steel is now at the newest firmware.  No software at the charger is required to make the watch charge.  The watch is only looking for 5 Volts DC at USB standard current of 1 Amp, apparently.

 

The Pebble Steel is now a product that has been discontinued.  The memory in it is lower than the newer watches, and the operating system firmware can not be updated past the last of version 3.  Newer watches have version 4 available.

Like I said, it works for me.  Good luck!

Converting a Solar Light to Low Voltage Using a LM7805 Voltage Regulator

Standard Internet Warranty Applies here:  Ramblingmoose.com takes no responsibility for damage.  If you wire this up incorrectly, shock hazards may occur.  You could burn yourself with the soldering iron.  You could also cut your finger and give yourself a “boo boo”.  We are not responsible.  We’re simply saying “Hey, it worked for me, it’s easy, give it a try!”.  The parts needed are commonly available online and can be read about in depth at this wikipedia page.

This is actually my Second Conversion.  The first one is in the first picture.

We’ve probably all chewed through a collection of solar powered lights for the yard by now.

I say chewed through because they generally do not last very long.  The first wave of lights were particularly awful.  Under powered, lit with a single LED that is about as bright as an indicator light on a stereo, and connections that are not suitable to be used outdoors,  you may get a year out of these if you were lucky.

Then there came another wave with brighter LEDs, but they wouldn’t last long due to the batteries failing in about a year.

There is a theme to this.  Batteries have a set number of times that they can be recharged.  No matter how cheap or expensive the light, if that battery that is being charged by the solar panel dies, the light is normally dead.

Besides, everything being cheap Chinese garbage manufacturing, you can’t generally get better life out of this stuff.

We went to a “rather nice” light the last time this happened, and got a year out of it.  Since I liked the fixture, I tried soldering in a collection of batteries to power the thing.  After the second try the light failed.  I set it aside hoping for a “Bright Idea”, pun intended.

Our own house ended up going with Low Voltage LED Security Lights.  My front porch is now bright enough to read from the light, and the power consumption is all of 4 watts at 12 volts AC.  Doing the math, that works out to 4/10th of a watt at 120 VAC out of the plug.  Adding the traditional 10 percent for error, we’re consuming 1/2 watt of mains power to light a room worth of porch.

Next to nothing to get our security lighting sorted out.

But those solar lights were waiting to be used.

Here is what I did…

The Solar Lights had a battery pack inside of them that consisted of three AA rechargeable cells.  Maximum voltage would be 4.5 VDC.  I had 10 L7805 Voltage Regulators here, and I decided to try one out on the solar light.  It would be over powering the light at the high end, but since the light was either being reused or disposed of, if I got a couple months out of it I was happy.

TS7805 Voltage Regulator.  Picture from Wikipedia.

A L7805 is a voltage regulator that puts out 5 Volts DC.  I had a low voltage supply for the yard at 12 Volts AC.  The wiring was simple, I put one together to see if it worked.

It did work.  It worked since the Light had three cells in its battery pack – 4.5 volts of AA batteries.  If your light is a different voltage being supplied, use a different voltage regulator!

I allowed it to run in the intervening two and a half months and it was still working.

So the L7805 converted the 12 VAC to 5VDC plus some heat.

The circuitry is dead simple.  Three conductors on the L7805.  The center conductor is the ground.  If you connect the positive line from the input to the first conductor, and the positive line to your appliance (my light) to the third conductor, you are done.

The entire soldering job took me less time than it took for me to take the pictures for this article.

These chips also come in differing voltage output from 3V to well more than I need at 40V. They all work the same way.  The voltage comes into the center conductor as ground and one of the two outside conductors as positive.  Voltage goes out from center conductor as negative and the other outside conductor as positive.

The proof is in my yard.  That easy.

Just remember, match the voltage regulator output voltage to the supply voltage of your lamp or other appliance.

How Bad Chinese Manufacturing Led Me To Make a LED Deng

A Deng is a Chinese Lantern.  They are pretty common, they are made out of a frame and paper that can be brightly colored or have patterns.  These aren’t the Sky Lanterns that fly through the air with a lit candle, this is more of a decorative “ball” type of a lantern.

They do seem to bring a smile to my face.  When I spotted one, I kept it thinking “I should do something with that some day”.

Yes, my house is full of those sort of projects.  Things I should do something with some day.  Moving from house to house should solve that but that is not in the plans.  So the Projects mount.

What happened to get it to where it is today is a long and twisted tail that involves alleged drunk driving, my own creativeness, and some truly typically bad Chinese manufacturing practice.

I’ll say this right off.  It is well known that people who make light bulbs of any type have been skimping.  There is a bulb in a firehouse that has been burning 115 years since the early part of the 1900s.  It is a “Centennial bulb” that looks more like the insides of an old Radio tube to me, but there it is.

That company that made the bulb never made any more money on that bulb and that’s the problem with Capitalism.  The light bulb companies conspired and colluded to make their bulbs less sturdy until you have the problem I had.

Helpful hint!  When shopping for Light Bulbs, look carefully at the packaging.  Make sure you buy bulbs that have a 25,000 hour life span.  Leave the lower hour bulbs at the store!

You see my Ceiling Fan broke.  I pointed a remote control at it and it didn’t turn on.  It refused to light, it refused to spin.  You need a Ceiling Fan in South Florida.  I thought I would procrastinate and in a few days we would go to the big box store and see if they still had this fan.   Going back to the well and seeing if it was not dry meant we could exchange it for a new one.

They had them and we grabbed one.  As an aside, I got a spare battery for the remote, just in case.  Type A23 batteries.  The same type as in my Jeep’s alarm remote.  I need new ones for that too.  It turned out that with a new battery, the ceiling fan worked.

We put the new one up anyway, and that one worked.  But out of the six incandescent light bulbs that came with it, two did not work.  We are going to put LED lights in that anyway so I grabbed the bulbs For Projects.

The other part of this story with the drunk driving, allegedly, that is, happened about 5 years ago.  Someone had a tricked out truck with ground effect lighting and a stupidly loud horn.  He drove this beast into the shopping center near my house and proceeded to back it up, clumsily, into a parking space.  He also backed it over top of a cement parking space block and ripped out those same lighting strips, in four pieces.

The lighting strips, I of course, picked up.  For Projects.  Bright white LED Strips that will run on next to no current at 12 volts.  My brain racing, that means that I could basically have free lighting coupled with my solar charger and a couple old laptop batteries and … so forth.

I wired them up with old telephone wire that was discarded by the telephone company one day.  The wires were stiff enough to stand up to some abuse, and hold the LED strips upright against their own weight.

The little LED things would run for days on three rechargeable laptop cells, so they would make an amazing emergency light.  When power goes out here, it goes out for a very long time, especially when Mother Nature is involved.

I’m looking at you Wilma.  Two weeks without power on my block means it would not be a good time to vacation at the beach!

So when the bulb blew, For Projects became Now.  I tested them one last time.  One bulb was dead.  The other popped immediately when plugged in.  I had my base.

The cord was salvaged from an old Ikea lamp that was in my back yard for years.  It had a small candelabra fixture in it that the bulbs fit.

With a tap from a pair of scissors, the glass broke away.  I was able to use the scissors to chip away almost all of the rest of the glass and that gave me the connectors I needed.  Since everything I was doing was low voltage, I used blue construction tape to insulate things and wired up the contraption.  One connection to the ring, the other to the tip.

I had my Deng lamp.  Now, to assemble and “Smoke Test” it.   It worked!  Actually, it really looks quite nice.  Enough to light the desk under it and it is quite bright on a 200 milliamp, 12 volt power brick from an old caller ID box.  2.4 watts of power to get a light that is about as bright as a 40 watt incandescent bulb.

Now, I don’t know how long that will run.  Someone bumps into the connections, it will go dark.  It won’t shock anyone, that kind of power may run a portable radio, but not too much else.  But the light works.

A giant pile of broken bits, discarded wire, and a drunken mistake gave me a rather nice light.

And a story about my own electronic OCD.

Hey!  It’s a Project!  I’ll finish it some day!  Really!  I will!

No More Desktop Computer? Same Here!

I moved down to South Florida, Lock Stock And Barrel as the saying goes, in 2006.

Shortly after moving here, Florida Power and Light “decided” I didn’t need that desktop computer that I built.  There was a power spike and Poof! It was gone.

I was “That Guy”.  The one everyone leans on to fix their computer after their 10 year old discovered this cool website sitting on a server somewhere in Russia… that infected it with a virus.  The guy who built computers since Back In The Days of the 486. 

Remember those?

I would say it’s fair to put the number of Desktop PCs I’ve built in the area of 200, perhaps more.  It was never my job to do so, but it was always something that I found fun enough to do that I kept up with the trends.

Until I moved here.

Here is a 2 bedroom, 1 bath, 1200 square foot house.   Down from a 3 and 1 1/2 1900 square foot in Philly.

I kept my skills up, but there were some things that I found I really didn’t care for about a desktop computer.

The main reason why I stopped using a desktop computer was space.   My desk is in The Florida Room, and that room is the warmest one in the house.  The Redundantly named Florida Room would be between 5 and 10 degrees warmer depending on the time of year, and since I keep the house at 78 … I migrated to the living room.

The thing is that it required that I keep a desk out there.   That desk got used less and less and became a thorn in my side that illustrated what was said about Possessions Enslaving You.

While I was migrating off of that old desktop computer, I kept the desk there to do computer repairs when I needed to, but I realized that I was using the laptop more and more.   They got cheaper to the point where the laptop I use now costs less than some of the motherboards that I bought in the past.

Unless you were playing a game, you really didn’t need a cutting edge desktop computer in the home. 

I noticed that many of my friends and clients were doing the same thing.   Why keep a boat anchor next to a desk in a house cluttered with “goodies” when you really wanted to be in the comfy chair in a living room or media room with your feet up?

A cutting edge desktop computer got less expensive as a result.  You can get a good desktop computer from many vendors for less than $500 these days, but when you can get similar laptops for the nearly the same price it led me to ask why.

I still have parts laying around the house.   A spare power supply here, a fan there.   For the most part, that Hardware Closet I used to keep in Philly is reduced down to a box of odd junk and a computer case.   I haven’t been asked to repair a desktop computer in over a year – fix a Virus problem, yes, upgrade a laptop, yes, but fix a desktop?  Nope!

Besides, you’d be shocked how much benefit you’d get out of a couple gigs more memory, and a really hard look at what you have installed on the computer.  If you don’t need it, uninstall it!

It seems that a casual glance in a big box electronics store will prove my point.   Rows of Laptops being hovered over by people, curious folks tapping at a tablet to try to wrap their head around what it is, but the desktop computer aisle is empty.   It’s even hard to get someone to tell you about a desktop computer in a computer store these days. 

There used to be a great amount of strategy that you’d have to employ to get just the right computer.  Now, you pick your price point, buy a laptop, and within two years you start looking to see what’s out there again.

Which is great for me, since I have a nice stack of Hand-Me-Down laptops from people who know I’ll pass them onto someone who needs them.  Your computer “slowing down” is usually because something installed itself on your browser that needs to be banished – toolbars, for example are useless.

For the vast majority of us out there, those home users of the world, you do not need the high end computer that the salesmen of the world push you toward.  In fact, I’d wager if you really look at what you need, a 3 or a 4 on a scale of 10 would be more like it. 

Yes, I’m being deliberately vague there, this isn’t intended to be a specific discussion of what to get now, since many of these articles are re-read in the future.

So if the salesperson is trying to sell you a computer for the home that is a laptop, at least these days, if you’re paying more than around $500 or so, step back and think about it.  You may be happy with the ego side of the purchase, but you probably do not need the extra expense.  The one I’m using to write this on, I paid $225 for in September 2012, and I’ll probably get another 2 years out of it.

But the Desktop?  Stick a fork in them – in the home, they’re done.

How Do You Know it’s Time To Get A New Chip Reader

The Floppy is dead, the “Stiffy” is long gone, the CD is dying, the DVD is annoying to use.   Apple moved away from “optical media” for distributing their software years ago at this point. 

So just how do you move data around today?

For a while, it was Compact Flash cards that were almost indestructible.  They’re still around, but not terribly well supported any longer.  There were stories of these larger than a postage stamp sized square getting lost in the trash or dropped into the bottom of the pool and surviving.   I still have a few of these things from that era.

It went to USB “thumb drives” and the SD Chip or SD Card.  Most likely we all have a few of those thumb drives around.   They’re typically much smaller than your thumb, but when they came out, that is what they were shaped like. 

As for the SD Chips, I’ve got quite a few of those.  My camera uses them, my Android phone uses them, one lives in my laptop for professional data, and there is one that lives in my Nook tablet.  There are at least two sizes of them, but they’re all the same hardware so they can be used in many places fairly easily.

Today I had a few pictures to get off of the camera, and I couldn’t tell you where the cable for the thing was so I had to pop the chip out and put it in the reader.  I’m still waiting for it to read.   I’ve got a blue spinning donut on the Windows Explorer window telling me that it just doesn’t know what to do with all this electronic chaff.   I imagine the little person who lives inside of the LCD screen sitting there, scratching his virtual head, twiddling his virtual thumbs waiting to do something with this but it isn’t quite right.  He’s about the size of an ant and looks like one too because I see him walking around on the outside of the computer once in a while.

You see, the chip reader is “flaky” and it’s time for a new one. 

I guess that means that the pictures of the Penta, Bougainvillea, and Hibiscus from the back yard will have to wait for another day. 

SD Cards are fairly “robust” and put up with a lot of mistreatment.  There is one of them sitting bare on the “mulch” that is on top of my table between the two big green chairs in the living room.  It really should be in a device like a computer but there isn’t any real pressure for me to do so since I trust it to survive being placed between a copy of Information Week and last month’s check register from the Bank. 

On the other hand, the $.59 reader that I had shipped from a web site a while back isn’t doing too well.  I’m afraid the patient isn’t going to survive Mr. Moose.

I’m sitting staring at a translucent box plugged into the USB port in the side of my laptop in what mom would have called “Bilious Green”.  It’s got my 8GB chip sticking toward me like a computerized electronic tongue saying “Neener Neener Neener, I’m not going to give you those pictures! Bwahahah, go find something else to do!”.

I guess the Gods of the Devices aren’t in my favor and I’ll just have to wait a week for that new $.59 reader to get here from my friendly UPS Driver or my friendly USPS Postman.  Both nice folks.  We’re lucky that way.