Low power design
Hello,
I am using TOP252 IC based power supply to drive a relay board. The output voltage is 5V and maximum current is 0.45Amp when all relays are driven. However the load current drops to 0.12Amp when no relay is being driven. I have attached my schematic which is generated by the PI Expert Software. My question is this - As circuit is designed considering 0.45Amp as output current, will there by any performance issues if the current drawn is minimum(0.12Amp) for a long period of time. Do I need to take special measures for this variable load power supply design.
Regards
Devansh
댓글
Hello Pike,
Thanks for the reply. I have checked the data points as requested by you and below are my readings
1. Lowest load
- Efficiency - 68%
- IC temp - 3degree C above ambient
- Transfomer temp - 5 degree above ambient
(It seems that output capacitors are getting heated up and which lead to transfomer temp rise)
2. Highest load
- Efficiency - 67%
- IC temp - 6degree C above ambient
- Transfomer temp - 8 degree above ambient
At highest load the temp rise is higher maybe because of some heat generated from the relay driving circuit.
Kindly let me know your feedback on the above observations
Regards
Devansh
Hi Devansh,
Thank you for the data.
Based on your data everything is working fine, there should be no performance issues when it will be soaked for a long time at the lowest load.
Regards,
PI-Pike
Hi Devansh,
There will be no problem if the output current is performing at minimum (0.12A) even for a long period of time, all of the stresses on the components will be less than full output current. But just in case, check the temperature difference of the IC and Transformer on the two output current conditions. Also check if the efficiency is enough at the minimum load.
Regards,
PI Pike