Power Supply 3 Volts 500mA

[satpam]

Is there anyone can help me, to search or design 3Volts power supply for my old walkman casette player. i use ordinary adaptor DC 3Volt but still hear some hum noise (50hz ?)

 

[pranam77]

If you hear hum, it says the filtering is not sufficient. Try adding 4700 microfarad/ 25 or 16 volts capacitor across the adaptor output ternimals. Take care of the polarity. In case you know a bit leletcronics knowledge and can assemble a small circuit, do have a look at the datasheet of LM317 with which you can get regulated 3 volts but it requires minimum 6 volts as input for the device...Cheers.
**broken link removed**