use a stereo connector,connect it to the line in of your sound card,the three wires that u get out are two channels with a common(earth)
the max bandwidth of pc sound card is 20-20khz and smps pwm operates at ultrasonic freq. so dont use pc osciloscope for freq above 20khz lest it (WILL) explode
so fix pwm ckt freq. at safe 15khz from datasheet fm,and observe waveforms. if all well then replace components for desired freq but now DONT CONNECT TO PC ELSE.....
the max bandwidth of pc sound card is 20-20khz and smps pwm operates at ultrasonic freq. so dont use pc osciloscope for freq above 20khz lest it (WILL) explode
so fix pwm ckt freq. at safe 15khz from datasheet fm,and observe waveforms. if all well then replace components for desired freq but now DONT CONNECT TO PC ELSE.....
Yeah, google, google, google... did I say google? 
This is a great place but it's never going to be a one stop shop.
Your sound card should work at line level, dig up the specs on the card. A safe bet "might" be 1 volt rms, you decide.
You'll need a buffer between the supply and to scale down the voltage as well. You can find projects online to give you some ideas. You might check out what's become a highly annoying site known as epanorama.net I think, should have something to that affect there.
But really.... if you want to get into this stuff, go to Ebay and find a scope for yourself, a sound card can't help you here. You can probably find some old scope that half works for next to nothing, shipping it will cost more than you paid to buy it, and you'll do alot more alot safer than you can with a sound card.
Regards,
Chris
This is a great place but it's never going to be a one stop shop.
Your sound card should work at line level, dig up the specs on the card. A safe bet "might" be 1 volt rms, you decide.
You'll need a buffer between the supply and to scale down the voltage as well. You can find projects online to give you some ideas. You might check out what's become a highly annoying site known as epanorama.net I think, should have something to that affect there.
But really.... if you want to get into this stuff, go to Ebay and find a scope for yourself, a sound card can't help you here. You can probably find some old scope that half works for next to nothing, shipping it will cost more than you paid to buy it, and you'll do alot more alot safer than you can with a sound card.
Regards,
Chris
Well, I know the topic is going in a different (maybe good) direction but reffering back to the start post......
I would try the 41 Hz amp 3. That is if you feel comfortable soldering SMD parts.
They cost you 25 bucks and are very, very hard to beat.
I've just finished one and it is a steal!. I've tested whether the volume is sufficient and on 8ohm and less than 88,5 dB (1W/1m) loudspeakers the volume levels are way above my normal listening levels.
On 4 ohm car speakers they will output more power.
Having sad that, if you want a subwoofer in your car I think this amp might not be suffiecent, consider a separate subamp instead.
Please note this amp cannot be bridged and in addition you need to keep the minus of the speaker outputs separate/insulated. That means that you have to insulate your speakers from the car chassis.
If you can find (or have available) modestly efficient car speakers I think that you will not be dissapointed, both in volume and in quality.
I would try the 41 Hz amp 3. That is if you feel comfortable soldering SMD parts.
They cost you 25 bucks and are very, very hard to beat.
I've just finished one and it is a steal!. I've tested whether the volume is sufficient and on 8ohm and less than 88,5 dB (1W/1m) loudspeakers the volume levels are way above my normal listening levels.
On 4 ohm car speakers they will output more power.
Having sad that, if you want a subwoofer in your car I think this amp might not be suffiecent, consider a separate subamp instead.
Please note this amp cannot be bridged and in addition you need to keep the minus of the speaker outputs separate/insulated. That means that you have to insulate your speakers from the car chassis.
If you can find (or have available) modestly efficient car speakers I think that you will not be dissapointed, both in volume and in quality.
hey homer
read this
http://sound.westhost.com/bi-amp.htm
its part one of two part series.it will convince u to do biamping using active filters if u can read it patiently.thepoint i wanna drive home is that after biamping,even small power amp will sound big due to reasons stated so u wont have to look at monster power amps for subs.
as a buffer,use 100k res in series with each o/p.it will reduce voltage level drastically.see with mm that its less than 1v else sound card goes.............
use only metal film resistance else noise will also come in pc scope.
read this
http://sound.westhost.com/bi-amp.htm
its part one of two part series.it will convince u to do biamping using active filters if u can read it patiently.thepoint i wanna drive home is that after biamping,even small power amp will sound big due to reasons stated so u wont have to look at monster power amps for subs.
as a buffer,use 100k res in series with each o/p.it will reduce voltage level drastically.see with mm that its less than 1v else sound card goes.............
use only metal film resistance else noise will also come in pc scope.
I don't know how much this will help but I've built this and am still using it as well as a few I've made with different output voltages.
I built my very first switcher using rod elliots instructions as well http://www.canze.org.nz/bcae/trnsfrmr.htm to help with getting the correct turns on varied core sizes and materials.
I didn't have an o-scope then and was somewhat succsesful on my first attempt on a proto-board no less so it can be done.
Although now having, even if a little antequted, a techtronix 475a
O-scope I don't now how I was so lucky. They are very helpful.
Let me know if I can help.
I built my very first switcher using rod elliots instructions as well http://www.canze.org.nz/bcae/trnsfrmr.htm to help with getting the correct turns on varied core sizes and materials.
I didn't have an o-scope then and was somewhat succsesful on my first attempt on a proto-board no less so it can be done.
Although now having, even if a little antequted, a techtronix 475a
O-scope I don't now how I was so lucky. They are very helpful.
Let me know if I can help.
hi xplode,
good link.great one i should say.i always had probs with xformer winding.ckt was finished in few hours(from pcb to full done),but perfect xformer wiring was a pain in ***.wind unwind wind unwind........to get symmetrical o/p.
hi homer,
couldnt post bec of festive season.will post the pics soon(today).how much u done smps?made tripath amp????
good link.great one i should say.i always had probs with xformer winding.ckt was finished in few hours(from pcb to full done),but perfect xformer wiring was a pain in ***.wind unwind wind unwind........to get symmetrical o/p.
hi homer,
couldnt post bec of festive season.will post the pics soon(today).how much u done smps?made tripath amp????
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