Super substitute for a 78xx linear stabilizers (5V/3.3V)

This device was designed to get a +5V and +3.3V power supply, which could replace the standard linear stabilizers like 78xx.
Assumptions:

1. transducer dimensions not larger than a typical 7805
2. outputs similar to 78xx outputs
3. could be anywhere, where it is necessary to replace the 7805 on this stabilizer
4. working in large range of input voltages 8-24V

Why to change the 78xx – it heats up very much, even when loaded with 100mA, and even that the 7805 is made to work with 1A, when 600mA is loaded, the chip melts without a heatsink.

This device doesn't have this defects, also, it has some benefits:

1. theoretical current efficiency 3A – but in this kind of small housing, only 1.8A was practically reached
2. on 600-800mA, the device isn't even warm
3. on 1A-1.2A it's slightly warm, but there is no need to add a heatsink
4. 1.2-1.5A it's quite hot – but it works
5. one jumper to change from +5V to +3.3V
6. it's slightly bigger than 7805, but it can be replaced everywhere
7. to change to 2.5V or 4.2V it is very easy – just replace the dividing resistor
8. input voltage from 8 to 24V – the suppressor chosen for about 12V
9. feet spacing is typically 2.54mm

All the elements are SMD type (0603 size). Only the suppressor, input capacitor and Schottky diode are bigger. The suppressors used are for 1.2A current, therefore, the efficiency is about 1A, the suppressors in the photo were rewind to get bigger current – 2.5A. The generated signal has about 200kHz.
The whole device works on A8498.






Link to orignal thread – Super zastępca dla stabilizatorów liniowych typu 78xx (5V/3.3V)