Heat bed replacement MK2a

Ok so lets start with I had a problem with not knowing the original limitations of the Solidoodle 3.  Within the first 10 days I burnt out the heat bed.  I kept the temperature at 90*C. 
I looked for a replacement.  I bought a MK2a PCB board off of ebay for about $8.  Not too bad of an error or so I thought.
When I installed it i noticed that my power supply kept resetting.  Basically it looked like a blink light for a 3d printer. 
Ok so I tried some left over ATX power supplies I had.  The problem was that I needed amperage for any MK2 heat bed, 15 to be exact.  The bed itself was only about 0.8 ohms. 
The next purchase was a power supply.  360W 30 A power supply again ebay for about $30.  Little bit costly but atleast the rest of the printer would have more power.

This worked amazingly.  I hooked it up and it ran for a solid 10 more days constantly printing.  ( I got lucky with the MOSFET not buringing out early).  And then blue smoke (something had burnt out).

My first reaction was to buy some replacement MOSFETs, to replace the burnt out one. The only problem with just replacing the MOSFET is you have to add a heat sink and a fan and a slew of miniature modifications, just so that this problem doesn't happen again.  I hate doing things twice.

So I remembered that mosfets are basically small versions of relay switches. So I fixed the board, and then I added a relay swtich directly from the board. Make sure this relay can handle 30A(Err on the side of caution).  Making sure you add a small rectifier diode so as to protect your board.  The first Picture shows the Working diagram.  The relay was not expensive, and an alternate would be a solid state relay, but it is more expensive.  This solution has kept my board super steady and allows for a very fast heat up time.

After making sure it worked I attached it all to the frame.  I have not had any problems yet.

I have attached pictures of what it looks like and the wiring diagram.