linear regulators

Other Hardware General Electronics
39

polymorph:
Sorry I didn't see this to reply sooner.

Not true. Both will have equal efficiencies.

Power will still be spread across multiple devices. Consider a power supply with 18V, 12V, and 5V regulators powered from a 24V supply, each circuit drawing 0.5A.

Individually:
(24-18)*0.5 = 3W
(24-12)*0.5 = 6W
(24-5)*0.5 = 9.5W
Sum 18.5W

Daisy chained:
(24-18)*1.5 = 9W
(18-12)*1 = 6W
(12-5)*0.5 = 3.5W
Sum 18.5W

You still have one regulator dissipating about 10W, but you have the further possible complication of the downstream regulators and circuits misbehaving due to sequential powerup.

If you want more efficiency, use switching regulators. And do NOT daisy chain them!

Well, I guess that's what I get for relying on "intuition" rather than doing the math. :stuck_out_tongue:
But, there is a slightly better spreading of power dissipation.