Hello,
I have a digital radio which is powered by four AA batteries or with an external power supply which provides 6V DC.
I would like to build an adapter to use the radio with a regular USB connector. Since USB only delivers 5V I used a small step-up module (based on MT3608) to step up the voltage to the desired 6V. The radio powers up but it can't detect any radio station. I guess stepping up the voltage induces some high frequency noise which is disturbing the radio somehow.
Checking the power line with a scope I found out, that there is a Vpp of approx. 800mV at 1.2MHz (which is exactly the switching frequency of the MT3608). I assume this is too much for the radio...
My question is, how to filter/smooth this properly. I tried different things using obviously a capacitor, some inductors I had laying around and so on, but nothing really helped. Could you please give me an advice?
Thanks
I have a digital radio which is powered by four AA batteries or with an external power supply which provides 6V DC.
I would like to build an adapter to use the radio with a regular USB connector. Since USB only delivers 5V I used a small step-up module (based on MT3608) to step up the voltage to the desired 6V. The radio powers up but it can't detect any radio station. I guess stepping up the voltage induces some high frequency noise which is disturbing the radio somehow.
Checking the power line with a scope I found out, that there is a Vpp of approx. 800mV at 1.2MHz (which is exactly the switching frequency of the MT3608). I assume this is too much for the radio...
My question is, how to filter/smooth this properly. I tried different things using obviously a capacitor, some inductors I had laying around and so on, but nothing really helped. Could you please give me an advice?
Thanks