24 Volt heated bed on a 12v system

Hi
I have a CoreXY printer 300*300mm. My heated bed runs on 12volt (or 24V) and it take a long time for it to reach temperature.
Is it possible to use a 24volt PSU for the heated bed and some sort of relay between the PSU and the connector on the Ramps?
All the rest of the elektronics in running on 12 volt.
Thank you

Use and external mosfet...

eg [www.aliexpress.com]


plugs into your normal bed output and it switches 24v on/off


Dont use a relay, the clicking will drive you insane (and the arcing will eventually weld the contacts shut)

When the heater is for 12V and 24V you won't see a big difference in heating up. You could try to raise the output of your 12V PSU to 14V to reduce heating time.
( If the rest of your electronics can handle 14V too )
I bought a cheap 600W DC-DC-boost converter to increase 24V to 28V because Duet boards are rated up to 25V only. That was a major difference. OTOH you can only use bang-bang heating mode, but my bed temp still is within 0.2°C.