The ACR MarkII boards are a step forward in the ACR concept. (ACR is short for Aftermarket Controller Interface)
The Original boards did exactly what they were needed for, they allowed people who don't have a background in electronics to install an Aftermarket controller quickly and successfully. I was surprised at the number of people with an electronics background who purchased them as well. They noticed that the ACR kit is very nearly as cheap and doing it yourself, and you don't have to spend hours figuring out part numbers, ordering all the parts and then still taking a chance that if even one wire is wrong, you can damage a Smoothieboard, your laser, or both.
The original run of ACR boards sold out briskly, keeping me very busy during it's run. While building the kits as fast as I could, I identified several improvements that would speed assembly for me and for the user, and features that would add functionality and ease troubleshooting if it were necessary. (fortunately, there were only 2 or 3 of the 26 kits owners who contacted me with problems, and they were minor. I learned to make plugs unreversable, instructions clearer and electronics as forgiving as possible.
I also made a gadget which was just a plug with LEDs in it to quickly verify operation of the end of travel limit switches. A Laser firing light soon followed. These are integrated in the MarkII.
It was discovered just how bad an idea it is to fire a laser with negative logic. Ov to fire and 5v to turn off is just a bad idea. This has been addressed, and now if your Smoothieboard goes down, or is busy booting, your laser turns off, not on.
The voltage regulators have been changed, where a linear devices were used in the 1st ACR, now the major 5v regulator is a switching type and doesn't require a heatsink (the linear chips were a source of headaches, from counterfeit chips to moving them to the frame to heatsink them well, I knew there was a better way). The Switching regulators now regulate the 5v, and the 3.3v is a much smaller linear device that is PC mounted. There was no demand to use this as a power source, so it has been scaled down to efficiently meet ACRs needs. This has allowed a reduction in module size. Some people had told me they wished the module was smaller and I'm working to grant that wish.
I did build a custom 12V powered ACR module for a gentleman who already had a large 12V supply in place and didn't want to re-wire his whole laser. I replaced the 24v power supply with a Boost switching regulator module, and it worked out great, offering a very slim module as well as saving on rework.
To sum it up, the NEW, MARK II ACR Module is leaner, meaner and even easier to install.
It comes with 6 LEDS, and has a header to plug in an optional front panel LED cluster that duplicates these functions. These are 24ma 5V outputs and can be used for driving/interfacing other equipment as well as driving LEDs.
Installation is easier. Unused and redundant connectors have been eliminated, reducing confusion, and the possibility of connecting it wrong.
These are the obvious changes, that the customer will appreciate right off, but there are several "out of sight/out of mind" changes as well.
It has the switching regulator, runs as cool as ice, at about 98% efficiency, and allowed the reduction in PSU size which has reduced the module size slightly.
While it retains the automotive industry main fuse, which allows easy availability in a Sunday afternoon, and good short circuit protection, the voltage regulators are protected with a "Polyfuse", a self resetting current limiting device that looks like a resistor, but rapidly opens the circuit on overload, preventing damage if the 5V is misconnected. Simply correct the error and restart the ACR, and the Polyfuse will have reset itself.
One major advantage is that, once in the system, I will be able to get these out to the customer with less time to build. This means I can finally get to all the other great products I have in store for you....
WOW! Scott what a great job you have done and look forward to what you will offer in the future. Thank you for sharing your knowledge and making some great products that help continue the legacy of the K40 laser community.
Awesome news Scott. Looking forward to adding it up on the website 🙂
For future reference, when you post something here if you want to share it across to G+, you can click the little "Google" icon in the bottom-right corner of the post (after you have posted) & it will allow you to share to your Public wall there (which you can then reshare easily to the K40 Community).
Scott Marshall: 5
Bruce G: 3
eric bradley: 1
Guest Posters: 1
Most Users Ever Online: 15
Currently Browsing this Page: