I am currently using the following setup for power supply of a stand-alone arduino and other peripheral devices:
Upto 30V DC / 24V AC
12V DC at about 200mA (for relay coils) and
5V DC at about 80mA
Later I decided to also power a wifi ESP8266 module from the same power source. This increases the power consumption of the 5V rail to about 250mA and hence the power dissipation on the 5V regulator is (12-5)*0.25 = 1.75W. Taking into account thermal resistivity of the regulator etc, the temperature rise exceeds 100 Deg C which results in regulator shutdown.
I am now considering possible changes to address the above issue. One way would be to increase track area which will offer further heat sink capability and hence reduced thermal resistance and lower temperature for the regulator. However, I cant really tell beforehand how effective this method would be. In addition the power loss on the LDO is too just much let alone the thermal issues.
I am looking for suggestions to improve the above power supply system with minimal if possible changes while also keeping the cost down. I know its always a trade-off!