First switching power supply working.
I have an ARM board to be powered, which draws between 0.5 and 1.5 ampere’s on 5 volt. Tried using an standard 7805 (2 ampere spec), but the system would not boot. VOut dropped to 4.5 volts and 7805 was getting to hot with +/- 24 volt VIn.
So i made an circuit based on the LM2576T-5.
|IC1: LM2576T-5||€ 1,60|
|L1: Inductor 100uH||€ 1,45|
|D1: SR504||Recoverd from PC PSU||5.0 Amps Schottky Barrier Rectifier|
|C1: 470uF 35v||Reused from other project|
|C2: 3300uF 10v||Also recovered from PC PSU|
|F1: Fuse holder and 400mA||Stock, price n/a|
Input voltage is an battery+solar power supply that varies between 23-24 to 29 volts.
Working power supply (left) with active load.
Bad output: (spikes)
What happens if an normal (or to slow) diode is used:
Yellow is regulator V-OUT.
Blue line represents voltage output for load (feedback signal).
Borrowed lm2576 library for Eagle PCB Design from eaglecentral.ca | LM2576 circuit