Input voltage for MR16 > 12V

[mschell]

At the bottom of the comparison table on the wiki, it states that the MR16 can be used with 24V power input, with the caveat that you need to put a heatsink on the L7805 voltage regulator.

This implies that I can switch/dim 24V components on the outputs of the controller.

Is this possible - i.e. for larger LED control vs. just MR16's.

[WWNF911]

Although I don't recall reading that, it should be noted that the MR16 controller was specifically designed for use with the 12V MR16's supplied by Wirekat.

Leon

[RJ]

It might be possible but that is a lot of voltage for the 5v regulator to dissipate and I expect it would run hot even with a heatsink. Have not tried it as it was intended for 12v MR16's

RJ

[RJ]

It might be possible but that is a lot of voltage for the 5v regulator to dissipate and I expect it would run hot even with a heatsink. Have not tried it as it was intended for 12v MR16's, It also has a curve for the mr16 so not sure how well the dimming would other lights.

RJ

[mschell]

I just thought I'd ask.   If it's not supported or suggested, then we need to update the wiki, and take out the reference to 24V.

I know the curve for dimming is designed for the MR16's.  But perhaps high-wattage LED's might work too.

[vziukas]

What if I cut 1 trace which goes to 7805 and supply 12V, and connect 24 to the triacs. Common ground.
Will it work ?

[RJ]

Yes and if you use 24v it may work as is but you need to watch to see how warm the 7805 runs and I would put a little pice of aluminum as a heatsink on it. But may work fine. I did not mean it would not work it just might not.

RJ

[mschell]

Went to RadioShack and got a TO-220 aluminum heatsink with long fins.   Cut it down a bit so that the HS wouldn't touch the triacs or whatever was close to the 7805 regulator.

Running the MR16 from a 24V power supply so I can drive the LED floodlight board as it was designed.   The HS and 7805 get fairly warm, but it seems to work just fine.

Will be trying this out with at least 2 floods by Thanksgiving, and will post back here...

[RJ]

If under worst conditions the heatsink stays less than 160 degrees F you will be alright.

RJ

[mschell]

If under worst conditions the heatsink stays less than 160 degrees F you will be alright.

RJ

Given that I can put my finger on it and leave it there, I'm sure that it's staying under 160 degrees F.

Thanks!

[RJ]

Oh yeah your fine! have fun thats what I build the stuff for!

RJ

[riri7707]

Works for me....
i made it = 5 v for the core PIC, drivers, etc... ( i take off the 5v regulator too)
24 volts for the charge...

Why, because most of the wired strings leds on the market comes with 24 volts after the provided transformer and tricky command box....

So it runs perfectly for me....

Inconvenient : you need a PSU with 2 regulated voltages or better : small one 5V out and a big one 24v for the mosfet drain current...

In all cases, it was great, as i can use standard 10m led (100 led) strings from the market who cost around $7 unit including the shipment cost from CHINA....

I love DYI.....  
Henri

[z327]

If under worst conditions the heatsink stays less than 160 degrees F you will be alright.

RJ

With 5 MM's on at 100% and 24V input, I'm seeing just 90F with my laser temp gauge.