polashd
Member
I build a circuit with LM2596HV-adj (smd IC). mounted it on a small heat sink. Input 37v dc input cap 100uf, output variable from 1.25v to 15v dc, output cap 220uf +330uf, inductor 100uh (toroidal). I used 2 flyback diodes (fast diode), one across output one between output pin and input pin of ic. Connected a dc motor of 12v 3A. when it runs output dopes to 10v current draw 1.5A max (transformer is not that powerful I guess ). I ran it for 5-10min. IC and transformer gets hot (to touch, not much). Next morning I ran it for 2 min only- the IC got damaged the output became 32+v without load (10v with motor). this is the second time same happened.
I asked chatgpt- got some suggestions – like Overheating, Inductor Selection (recommended 22μH to 33μH), Inrush Current and Load Spikes, Insufficient Input Filtering, Over-voltage Protection, Load Characteristics (Motor), Output Capacitor Insufficiency.
Based on the suggestions I made some changes 1) reduced inductor value around 40uH, 2) added one 100uf capacitor parallel to the existing input capacitor (100uf).
Unfortunately the same thing happened again after 5-6min of running (IC got damaged for the third time).
What is the problem, what to do? Pls help
Nb.: my inductor core is Iron powder T-106-26.
I asked chatgpt- got some suggestions – like Overheating, Inductor Selection (recommended 22μH to 33μH), Inrush Current and Load Spikes, Insufficient Input Filtering, Over-voltage Protection, Load Characteristics (Motor), Output Capacitor Insufficiency.
Based on the suggestions I made some changes 1) reduced inductor value around 40uH, 2) added one 100uf capacitor parallel to the existing input capacitor (100uf).
Unfortunately the same thing happened again after 5-6min of running (IC got damaged for the third time).
What is the problem, what to do? Pls help
Nb.: my inductor core is Iron powder T-106-26.