After market bed heater for Intamsys Funmat HT 3D Printer
If you're a brave individual you might try insulating the bottom of your heated bed. You're going to want to get fiberglass or something that can actually withstand the temperatures you're trying to reach; anything past about 230&nbsp;&deg;C and you'll get organic things like cork and cotton starting to smoke. 200&nbsp;&deg;C is pretty absurd for a print bed temperature unless you're printing some pretty exotic materials.

Aside from insulating the bottom of the bed to aid in heat retention, you might also try getting an external FET chip for your heated bed, like is recommended for the RAMPS1.4 boards since their connectors don't handle high amperage loads well. External FET plus a 24&nbsp;V PSU might give you the kind of temperature range you're apparently aiming for. Best of luck with that, and try not to set your entire setup on fire, 200&nbsp;&deg;C really is kind of absurd for an entire print plate.

TL;DR:


Insulate
External FET chip
24V PSU