Introduction: DIY LED Replacement Bulbs for 12 Volt Landscape Lighting Wedge Base Bulbs

Picture of DIY LED Replacement Bulbs for 12 Volt Landscape Lighting Wedge Base Bulbs

A while ago I decided to minimize our energy usage using LED lights wherever possible. Why not start in the front yard? I was using a 500 Watt supply and now use a 44 Watt supply!  I looked online for Wedge Base LED Bulbs. I saw lots of fancy circuitry and weatherproof housings that were going into an enclosure on a regulated 12 Volt supply.  They provided dim light  and were not cheap! The cheap ones are a few dollars now. But you can make one for about 25 cents in materials. They also don't combine colors. We need to make a Wedge Base Bulb that will run comfortably on 12 Volts. This integrated circuit requires four components. In this case they will all be diodes, hehe.  

So here is what you will need to have on hand:
An existing 12 Volt landscape lighting configuration, Malibu, Toro, ect.

White 5MM LEDs ($4 per 100, Ebay)
Perforated circuitboard ($4 board, Radio Shack)
18 gauge copper wire
Rosin Core Solder for electronics

Soldering Iron
Dremel Tool (possibly a coping saw)
Wire Cutting Dykes/Stripers
Small Needle Nose Pliers
Heat Dissipators (hemostats, alligator clips)

Step 1: Cut the PerfBoard

Picture of Cut the PerfBoard

Cut the PerfBoard into strips. The strips must be the width of a Wedge Base Bulb. So mark each fourth row of perforations for cutting with a ruler and a thin Sharpie. You might want to double check your particular board with one of the Wedge Base Bulbs for width but this should be accurate. Then cut with your Dremel using an acceptable cutting attachment. I used the detachable wheel for metal. Don't forget to wear some breathing protection of some kind. A coping saw may work as well. I tried shears and wire cutting dykes with poor results as shown. When the strips are properly cut they will have three rows of perforations as pictured. Then clip each strip into sections with wire cutting dykes, or Dremel. Clip each one off at the 14th row. This will give you the right size and shape to mount 4 LEDs.


Step 2: Mount LED1

Picture of Mount LED1

LED1 will be mounted on the top of the bulbs circuit board. First choose which end of the board is the going to be the top. This will be the end that is smoothest. The rough cut perforations will help hold the contacts on the bottom end later. They don't hurt anything on the top so don't worry about that. Just put the most pronounced end on the bottom. Now slip LED1 into the outer top holes and bend the legs around the board and back up between themselves. Then bend them down and outward as shown. I used hemostats to get the leads under and through themselves and bent out. Wrap it fairly tight. I wrapped one leg at a time on LED1.

Note: LEDs are diodes and as such allow current flow in only one direction. Current passes from the (+ long lead) Anode to the (- short lead) Cathode. The Cathode is also known as the Anvil. In this case the LEDs are connected in series and polarity must be observed. So basically the Leds must be joined at opposing leads for current to continue to flow through. Attach Anode to Cathode. Never wire two anodes or cathodes together. Even if you pay attention you will probably mess up at least one. No worries though, it's an easy fix. But not one you will want to repeat too many times, hehe.


Step 3:

Picture of

Mount LED2 on the board as shown. Be sure to observe the polarity of the Led before bending the leads. This time try bending both leads at the same time up with your thumbs.  Again use the hemostats to get the lead ends between the leads and flared out.

Step 4: Mount LED3

Picture of Mount LED3

Mount LED3 on the other side of the board.  Again, be sure to observe the polarity.  It is reversed on the opposing side of the board.

Step 5: Mount LED4

Picture of Mount LED4

Mount LED4 as pictured. It doesn't matter which side of the board you mount LED4.  But polarity must still be observed in order to maintain continuity.  

Step 6: Mount the Contacts

Picture of Mount the Contacts

Here's where the copper wire comes in. A wire diameter just smaller than the hole is best. You can see now how the cut perforations are used. Use them to hold the contact wire when bending it around to meet at the other side where the wire starts. Clip the ends off high at the overlap point. The contacts need ample travel space in order to slide freely into the receptacle.

Step 7: Solder Contact Points

Picture of Solder Contact Points

Before you go heating up the soldering iron keep in mind that LEDs are sensitive to high heat . So you will need to protect them from your soldering iron heat by using hemostats, or alligator clips, to dissipate the heat before it gets to the LED itself. You will need at least 2 diodes protected at a time as you solder along. But you will have to move a clip forward as you work so the next diode is protected. They make little clips just for this purpose and they will work as well.  

As you are getting ready for soldering double check and make sure all the diodes are running in the same direction. Review the connection points. Soldering will add a considerable amount of stability.  But this is your last chance to spot any problems before soldering. Trying to desolder one of these isn't an option in my book.  

Note: My poor old soldering station (since replaced) was on it's last legs. So if my soldering isn't up to snuff that's why, hehe.

Step 8: Replace the Old Bulb !

Picture of Replace the Old Bulb !

It's time to change out the old bulb with your new LED bulb! It should light right up. But if it doesn't pull it and turn it around and try it again. If it still doesn't work plug the old one back in. If it still lights up it's time to troubleshoot the LED bulb. One of the LEDs may be backwards. Or there is a short, or broken connection somewhere.  If it's an Led just clip the offending leads off at the halfway point. This will give you something to solder the new one onto. Don't try reusing the one you clipped off. The short leads are a pain and chances are it won't survive soldering anyway. Besides it's preferable to solve the problem outright rather than chance further time loss and aggravation over a single  diode, hehe.

You can also use different color LEDs that have a Voltage rating near that of a white LED. Colors with lower Voltage ratings can of course also be used. But I'm pretty sure the number of LEDs would have to increase to five. I posted resource links if you want investigate further. I made the RWB light below with Straw Hat LEDs for Red and Blue. Because they are what I had on hand.  Straw Hat LEDs have a wider light dispersal and so are less focused. Great if you want something more moody.  I finally went with a few white/blue bulbs near the entry among the sea of bluish white lights in the rest of the yard.  One final thing. The lighting units you see here had three outer plastic rings. One is the lid. The other two slide over the lense. In these pics you can see that the center ring has been removed.  This was to allow for maximum light to emit from the device and improve the visual quality of my new LED landscape lights! You might think, "This is gonna take forever!". But I did 16 bulbs in three nights while watching a movie. It was really very rewarding to change out that 500W transformer. Just remember to watch out for...

Have fun and good luck!



korky0429 (author)2016-04-03

How are you calculating watt usage from the LEDs?

nyktunr (author)2012-12-16

Have you considered sanding the outer surface of the LEDs to get a more diffuse light from your four diodes? Nice energy-saving hack! :-)

All4FunOC (author)nyktunr2012-12-19

I hadn't thought of that. Now we have an option between standard and straw hat LED diffusion.

ryanbrennan11 (author)All4FunOC2015-11-30

Hello All4FUNOC! I have a question and I'm hoping you can help. the LED lights that are installed in some cement stairs that are Malibu lights arent' working. I purchased the house recently and want to fix them. It appears there is power to the lights but either the lights went bad or water ruined them I'm not sure but, I want to get lights back to the boxes to light the stairs. How can I make this work? This brand was not intended to go in cement but if there is a way to bring light back into these that would be great. thanks for the time.

ryanbrennan11 (author)All4FunOC2015-11-30

Hello All4FUNOC! I have a question and I'm hoping you can help. the LED lights that are installed in some cement stairs that are Malibu lights arent' working. I purchased the house recently and want to fix them. It appears there is power to the lights but either the lights went bad or water ruined them I'm not sure but, I want to get lights back to the boxes to light the stairs. How can I make this work? This brand was not intended to go in cement but if there is a way to bring light back into these that would be great. thanks for the time.

swimspud (author)2015-10-26

I've been looking for something like this forever, thank you! I grabbed 20 or so outdoor light stands that my folks were throwing away and want to rig up a system powered by a battery/solar "hub." Its as much of an experiment and learning experience as anything. Thanks again for the guide!

JamesB176 (author)2015-10-11

12 volt lights that use a three stage setup with 3, 6 or 9 leds (for example) would be awesome with an old school tri-base lamp.

RCD721 (author)2015-07-31

Love this ! Thanks ! Have a few questions, and please, excuse my lack of knowledge on LEDs. I have a 12 volt ac power supply for my Malibu lights. 200 watts. Can I simply make up the 4x LEDs like you detailed and replace the 7 watt bulbs in each fixture? Nothing else to add or modify in my system? Also, how do I add up my total wattage to select a more appropriate power supply? Each 4x = ? watts. Can I make longer runs than the 100' that was suggested using the old bulbs?

poiihy (author)2015-06-18

Here's the image of the difference between a regular LED and a cracked ice one. The one on the left is the regular unmodified one, and the one on the right is the cracked ice one.

poiihy (author)2015-06-18

The problem with this is that the LEDs have an epoxy casing that is shaped to magnify the light in one beam like a flashlight. As you can see this makes bright spots on the outside. To solve this I'd suggest to "crack the ice" of the LEDs. This means you chop the end of with a pair of snips. This will remove the curved front so the light is evenly distributed from the LED inside, instead of being magnified. It would also create a cracked ice effect which will help diffuse the light.

Read this:

You can also sand the LED like nyktunr said below.

barney.simmons.12 (author)2015-03-03

It appears that LED's are Voltage sensitive & not current sensitive. Can you connect two LEDs in parallel and still have the 4 sets of 2 Parallel LEDs in series?? Would that in effect give you twice the amount of light from that same fixture??

thinders (author)2014-04-02

Love it .........

I've ordered all the parts from Amazon.

Including Bridge Rectifier Diode 2W06 2 Amp 600 Volt Full Wave Rectifier

I will be using 4 ea LEDS

In a Malibu (or similar)

I want to see the brightness / color with / without the Bridge Rect.

Your set up, the LEDs are in series ... A ---> C ---> A ---> C

With the Rect I presume I can do either Series or Parallel (AA CC).

Assuming the Rect is marked (or I measure) for + / - (or I measure with a VM), I can't recall how the diodes are marked.... I seem to dimly recall that one of the LED leads has a "step" at the base.

Lastly ........ I was thinking "where can I test all of this" and recalled that my doorbell chime is on a 12VAC transformer I will have a test circuit right in my basement :-)

DIYtode (author)thinders2014-04-08

You cannot do series or parallel. Stick with series or your LEDs will burn out. The rule in this project still applies: put 4 LEDs in series. The full wave bridge is worth it. The flicker is gone! The bridge will be marked in some way to indicate the (+) output. In rectangular or circular cases the (+) is opposite the (-) which means the other two are the input, and go to the transformer wires. Sometimes the input leads are marked with tildes (~). If you have any problems post back and I will help you. The test should work OK. My unit is bright enough to allow me to line the inside of the lamp with a frosted plastic sheet and a warm gel filter and still I have a very bright light. The harbor freight LEDs are in vertical columns. You break the series trace for every column then wire in series. If you are just using regular single LEDs, just line them up all the same in series i.e. short lead to long lead. Long is positive. If you use the rectifier, it will work one way and not the other. No problem, just flip the circuit :-) But keep them in series (long lead from the first to short lead on second, and so on...) or you will have a burnout.

All4FunOC (author)DIYtode2014-09-29

Nice work! Break it down bro! And then post a link to your instructable. I've been messing with my new one for like a year.......I have the urge to wrap it up and publish. Thanks for posting.

DIYtode (author)DIYtode2014-04-09

Wiring diagrams that may help. Don't forget All4FunOC's warning, you must use identical LEDs.

DIYtode (author)2014-03-24

Very clever! Following your line of reasoning I converted the main panel from the 27 LED harbor freight worklight into a 24 light array by cutting the printed circuits and hooking each parallel set of 6 in series. I plan to install it into a standard "jar" porch lamp. Your LEDs should be brighter and the flicker will be mostly gone if you add a full wave rectifier to the circuit. Example is Radio Shack 2760268. You can get these very cheaply online, anything rated .5 amp or higher and 50 V or higher will work.

All4FunOC (author)DIYtode2014-09-29

My bulbs don't flicker. Just a nice smooth glow. I'm guessing the Malibu transformer has a bridged rectifier. My reasoning is low voltage and many small arrays. This allows the remaining arrays to function should there be a failure in one or more of them. Large arrays = higher voltage = less safe. So did you do an instructable on your porch lamp?

drums114 (author)2014-05-23

I was thinking about this. Can't you just take a set of old christmas lights, cut off 4 of them, strip the wires off the 2 ends and push them into the light socket? Would that work?

All4FunOC (author)drums1142014-09-29

Assuming you're talking about a 12 volt Wedge Base Socket, then yes, it might work, but not well. I wouldn't want to try it 16 times that's for sure. And that would depend entirely on your old Christmas lights and not my cool bulbs, hehe. Outdoor lights have to deal with moisture. Connections must be solid. Besides the light goes where the bulbs point. If it works, you will need a tree to hang the LEDs and direct their light. It seems I have made the tree and adorned it too, hehe. Peace.

thinders (author)2014-05-12

What is killing my LEDs ?

I followed the design, the LEDs are in series + to - , 4 ea per lamp. I used a single 600 V / 2A rect on the 12VAC output to provide DC to the 7 of lamps, output of the rect is 11.4VDC. Now all the LEDs are "dim" ........ Attached is a shot of 2 sets of 4, powered by a 12 vdc battery (spare Verizon FiOS 12 lead / acid ). You can see that 4 of the lamps are bright ....the other 4 are dim .......

What tests could I run on the existing LEDs to determine what is causing the failure ?

All4FunOC (author)thinders2014-09-29

I'm guessing you have figured it out by now. This instructional is on a simple T5 bulb construction. If you did follow the design properly then it's not the LED array's (bulb's) fault. It's the amount power applied to the circuit. My array is designed for 12V AC/DC. But LED's have a voltage operating range. This allows for an amount of dimming, or brightening, as the voltage/current increases, or decreases, within that voltage range. The 11.4V bulb is operating properly. I'm pretty sure what you are seeing is simply the difference between applying 11.4V (dimmer) to the circuit, or 12V (brighter).

FYI: Power Supplies aren't exact voltage. An average rating is +/- 5%

Sorry for taking so long to get back to you.

thinders (author)thinders2014-05-12

I should have listed, here is the LED that I used ....

  • Forward Voltage(V) 3.2-3.4
  • inant wavelength(mm)K:5000-6500
  • mcd:16000-20000
  • Power Angle (deg):120-140
drose25 (author)2013-08-30

Am I missing a step? Malibu and almost all traditional landscape lighting transformers output 12v AC. LEDs are DC devices. Usually a diode or bridge rectifier is used to convert the AC output to DC for LEDs but I'm not seeing it here...if you have these running on straight 12v AC I'd be curious to hear about their life span.

All4FunOC (author)drose252013-09-14

You are right about the AC part. No bridged rectifier in low voltage Malibu transformers. But the white ones work just fine. I haven't had to replace a single one. Now the experimental mixed color ones are a different story. I stuck with the same LED format instead of adding a fifth light. I'm liking the white anyway. So I'm good. They are still working great!

drose25 (author)All4FunOC2013-09-15

This was bugging me so I researched it. :D Apparently you can drive LEDs directly from AC as you've shown here, but it poses some potential problems. The first is the LEDs only light on one of the two alternating current cycles, so they are much dimmer than when run on DC. The other is LEDs usually have relatively low breakdown voltage and current tolerances and they can often be killed while trying to block the "wrong" current cycle. That problem can be fixed by just adding a regular diode to the cathode (negative) side of the LED series. It will block the reverse current from reaching the LEDs. The dimming part can't be fixed without a bridge rectifier, but they make really them small and cheap these days so they can be easily integrated onto your board or in a fixture if brightness was an issue.

Thanks for this instructable, BTW. I really like the way you used the perfboard as a T5 wedge base and neatly bent your LEDs for light dispersal. That was ingenious!

roger505 (author)2013-05-23

I love LEDs but for landscape lighting that color is horrible! Get some better LEDs with some good color or stick with a 4W halogen.

All4FunOC (author)roger5052013-05-24

Well thank you for stopping by and making your "positive and constructive" comment. But if you had actually taken the time to read that which you claim to dislike. You would have found that one may use any color he/she chooses. LED's lighting do take time to get used too before a person can love them. Now I not only love them but use them as well. Surely your great love of LED's has brought you more than a suggestion to stick with a 4 watt halogen? I'm being nice, so, ...Have a good day.

nameless1212 (author)2013-04-07

Hoping somebody happens to read this and can answer it. Why no resistor? I'm asking because I honestly don't know, everybody stresses that you need to have a resistor for LEDs to limit the current.

All4FunOC (author)nameless12122013-04-25

That's because there are enough LEDs in the circuit to handle a 12 volt load. If there were two LEDs instead. A Voltage Dropping Resistor would be required to adjust the load so that the now excessive current is handled by the resistor in the form of a voltage drop. More in-depth details can be found on the links on my pages. Have fun!

Kurt E. Clothier (author)2012-12-15

Nice work. I've been slowly replacing every bulb in my life with LEDs as they go out or I just find some free time on my hands. The hard part is getting adequate light output in all directions without using a lot of LEDs.

Thanks! Yeah, four LEDs work great for this though. They are bright and the light shoots right out at ground level. I like the Warm White Corn bulbs. But my kitchen runs on 6 3x3W LED downlights. I had to detach the spotlight faces and Dremel down half the oversized heat sinks to expose the light, hehe. Now I'm after 1" E27 extensions for them.

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