We often get asked "How do you reduce 24Vdc to 12Vdc" and the answer is pretty easy - you use a DC to DC converter which has a 24Vdc (nominal) input with a regulated 12Vdc output.
There are a number of advantages of this solution but one big advantage is that you can get a very stable 12Vdc output from a 24Vdc source which may even be wandering or diminishing. Most of the 24Vdc input DC DC Converters which we sell have an input range of 18-36Vdc and therefore as long as the voltage does not move outside of this range, you will be provided with a consistent and regulated 12Vdc Output
Here at Simply Power Supplies we have a wide range of 24Vdc to 12Vdc converters from 15W up to 360W and you can see our range here: 24Vdc to 12Vdc Converters
If you have a requirement for converting any DC voltage to any other DC voltage then please do get in touch!