Was gonna use my laptop soundcard output as a signal generator, just wondering if its okay to do, and what kind of input impedance should i use on my circuitry.

Megamox

 

Just had a thought, the earphones that you connect to an audio output are about 8-16 ohms. So i guess this is the nominal input impedance i should use for maximum power transfer right.

 

You don't want maximum POWER transfer, you want to feed the lowish impedance output of the sound card to a higher impedance to give maximum SIGNAL transfer. The earphones you connect are most probably higher than 8-16 ohms, older ISA sound cards could feed normal speakers, later (ATX onwards) sound cards require amplified speakers, they are far too quiet with passive speakers.

I suggest you are EXTREMELY careful, it would be a shame to destroy your laptop?.

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Would be indeed, not something i can afford to do!

 

Lemme make sure I've got this impedance matching stuff down:

MAX POWER TRANSFER:
Match input and output. Transfer is 50% maximum.

MAX SIGNAL TRANSFER:
Low impedance -> High impedance. Is this close? Anything else I should know?

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You should know that the low impedance of the sound card's output has enough power to destroy itself or a load. If the load is an electronic circuit and the output level from the sound card is too high then something will probably be destroyed.

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