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12V Dimmer Kit V2 Now Available

12V Dimmer Kit V2
12V Dimmer Kit V2

Here it is, finally! The 12V Dimmer Kit V2 is now available.  You can buy one in my on-line store for only $14.95.  They are also available from BG Micro in Dallas TX.

What is a 12V Dimmer Kit V2, you ask?  It’s an especially efficient PWM (pulse-width modulation) controller for 12V loads up to 60W.  Use it to variably dim LEDs or control the speed of DC motors.  It comes as a kit and you solder it together.

Have a look at the User Manual and Assembly Instructions (1MB PDF).  I’ve also got a schematic diagram available for your inspection.  The source code for the microcontroller is also freely available, if you’d like to tinker around with its innards, or just take a peek.

The 12V Dimmer Kit V2 is both new and improved.  “How can it be both?” you ask.  I’m glad you asked.  This is a redesign of of my previous 12V Dimmer Kit and includes several improvements in both the hardware and the software.  I’ve also added some completely new features that were not present in the original kit, so that makes it new as well.  See?  Aren’t you glad you asked?

This kit started out as a simple dimmer for one of my IR Spotlights.  A customer in the UK wanted to photograph bats at night and needed a variable infrared source for his camera.  I built two of those dimmers and they worked well for the intended purpose, but I was never really sure how well it would work in other applications.  Another customer showed me a kit he was buying from overseas and I thought I might try making my own.  It worked pretty well at about 25W and sold out every time I built a batch of them.  Unfortunately, I had designed in a component that was once cheap & plentiful in the surplus chain but one day ran dry.  It took a long time to find an adequate replacement that I could count on.  Once I did, I sat down and started designing the new version, hoping to basically duplicate the success of the previous circuit and make a couple of small improvements while I was at it.

Then yet another client wanted a custom version of the dimmer that was operated by a simple push button instead of a dial.  I could get so much work done if it wasn’t for these pesky customers!  (tee hee hee)  The push button version worked well enough, and it made me want to add that as a feature to the existing dimmer kit.  That was kind of tricky!  The upshot is that the new (and improved!) 12V Dimmer Kit V2 will work with either the dial adjustment (a potentiometer) or the push button – or both.

I also wanted to up the power-handling capacity to at least 50W.  I added an extra amplifier stage to the output driver, and was able to get the new kit to handle up to 60W without a heat sink on the output transistor.  It gets a little warm but not much (i.e., you can leave your finger on it).

Thanks to all my beta testers for helping me test the unit in the field, point out obvious bugs and even blow units up.  Your help and attention to detail (and abuse of poor, innocent electronics) has made this a much better product than I could have possibly made by myself.

Let me know what you think in the comments.

Posted on 20 Comments

More is better, right? 12 LED Cylon scanner Prototype

While waiting for my 12V Dimmer Kit PCBs to arrive, I spent a little time building yet another Cylon-style LED scanner. This time it has 12 LEDs! That’s more than 5! Quick, someone do the math!
Here’s a short video showing how it’s coming along so far. It’s still on a solderless breadboard at this stage. I’m thinking about a PCB that’s about 4 inches long and maybe one inch across, or perhaps slimmer. It should run on two AA batteries.

Let me know what you think in the comments!

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12V Dimmer V2 coming soon!

12V Dimmer Kit V2 prototype with terminal labels
12V Dimmer Kit V2 prototype with terminal labels

** Update ** the kit has been released!

Here is an actual photograph of an actual prototype of the long-awaited updated version of my ever-popular “12 Volt Dimmer“.  It’s an especially efficient PWM controller for 12VDC loads up to 60W.  The previous version was only rated at 25W, so this is a big improvement in capacity.  Also, I’ve added an extra pushbutton to allow cycling through preset power levels, which are currently 1%, 10%, 25%, 50% and 100% and back to off again.

The 12V Dimmer kit will be available in two to three weeks (*crosses fingers for luck*) for only $14.95.  The production version will be much more attractive than this prototype, with a real soldermask and silkscreen.

Since the power terminals are unlabeled on this prototype, I’ve included this photograph to illustrate the proper connections for both power and load.

You can control a *LOT* of LEDs with this kit, as well as motors and fans as a speed controller.  There are actually a lot of applications for a simple circuit such as this.

All the design files, including the schematic and microcontroller source code will be released when the kits are ready to ship.  I have several units in the field being evaluated by my trusty beta testers.  Hopefully there will not be any big surprises between now and the launch date.