NTC is heating more
I have deigned 3 phase power supply of 60W output ,when i switch on the power supply with 3ph all the phase and the tracks got burnt.
So to solve this issue we have used an NTC value of 50 R after the bridge circuit .
Now when i switch on Smps will be on but at low voltage with max load NTC is heating at 106 C .
Please provide a possible solution to make the NTC to be at much lesser heat.
Comments
Inrush NTC's are meant to run hot ( ~ 100 degC) to go to a low resistance when the equipment is running - there is no getting around this, unless you use a resistor / relay combination on 2 phases to limit inrush.
Hi Mohan,
You need to measure or determine your maximum inrush current. From there size your NTC to reduce the inrush current to an acceptable limit. If in case you just need to use a resistor upon power-up to reduce the inrush current, you can put a bypass relay across that resistor to activate after the power supply starts up so it will not heat up during normal operation.
Regards,
PI-Picard
Regards,
Pi-Picard
You have fatal problems with the parts in your circuit - rebuild from new and check your design for fatal flaws several times.