Hello all,
I made a small audio amplifier using a TDA1517P, its basically used to amp a small mp3 player I have, via an external audio out jack. I plan on using a cars cigarette lighter for the power supply. My question is, should or can I use diodes between the audio input, and the amplifier? or something else maybe? I want to protect the mp3 player the best I can, Id rather pop a 50 cent fuse in the car than fry my device. I wired the 1517 per its "application circuit diagram" from the pdf file I found. Seems to work perfectly fine right now, just want to be safe though. Thanks.

 

well i think u should use small capcitor of 1uf 25volts in the audio input of the amplifier it will protect ur amp with dc voltage .

 

I suggest you using an optoisolator.

 

thanks for your responses. The amp is the least of my worries though. but worth looking into, would an optoisolator be able to carry an audio signal? I know they work great for switching on off signals.

 

I thought you wanted to block voltage spikes from the cars alternator. To isolate audio maybe Not, it could filter the high frequency signals since the LED response may be too slow.

 

I would like to isolate the mp3 player. Im not sure if voltage would come back to it, but I just want to be safe. The player has a line out jack, that I used as the 1 & 2 input for the 1517, just want to secure the player. The amp is expendible. Prefferably not, but much cheaper to replace. Sorry if I am not clear, its the best way I can explain what Im trying to accomplish. Your suggestions are very much appreciated.

 

Use an audio transformer between stages.