specifications are
input voltage - 24 volt dc
output 1 - 12 volt dc
output 2 - 5 volt dc
outputs should be isolated
output current should be 500 ma or slight less is considerable
You should mention your load regulation on the output. I assumed that 5v will be for microprocessor supply and 12V for ICs supply. Better go for a flyback converter with feedback as weighted values of two output.
specifications are
input voltage - 24 volt dc
output 1 - 12 volt dc
output 2 - 5 volt dc
outputs should be isolated
output current should be 500 ma or slight less is considerable
There are a few questions you should ask yourself.
500 mA each output, or 250/250 mA?
Is the input voltage a steady 24 volts, or does it have a range?
Outputs isolated from the primary only, or between outputs?
Anyways; I agree that a flyback converter, with optocoupler feedback is what you require.