I just made a switching mode power supply with L4970.
I used the suggested circuit diagram from the datasheet:http://pdf1.alldatasheet.co.kr/datasheet-pdf/view/22500/STMICROELECTRONICS/L4970.html
Figure 34, except the following:
- I use 80uH inductor
- and a voltage divider made from 10k and 5,1k connected from the output to the feedback pin (11)
The desired output voltage is 15V.
It works well if there is load on the output,
but without load the output voltage sinks to about 7.5V.
I tried to put some resistor to the output to achieve small constant load,
but it could not help well. At some resistor values I can hear also periodic soft clicking
from the circuit.
Do anybody have experience with this circuit?
Thank you in advance,