Computer Speaker Number Two
|
When setting up another 'new' computer I needed a speaker for it.
I've made such a thing before using an LM386 powered from a spare USB port but this time I had a problem. The only decent-quality loudspeakers I'd got were out of old transistor radios and had impedances around 25Ω. Driving one of those from a 5V supply meant that they were very quiet. |
I therefore tapped the computer's 12V rail. The snag with this is that it's electrically very noisy and there were weird and horrible sounds coming out of the speaker such as are seldom heard outside a jazz band, especially when the hard disc was being accessed.
Luckily a 47µF capacitor between the LM386's Bypass pin and ground shifted it.
That was the only thing of interest on the electronic side and most of my efforts went into the case. The design isn't mine: I saw it in a magazine and scanned it into my computer to make a cutting template. A copy of this can be found as a PDF here.
Luckily a 47µF capacitor between the LM386's Bypass pin and ground shifted it.
That was the only thing of interest on the electronic side and most of my efforts went into the case. The design isn't mine: I saw it in a magazine and scanned it into my computer to make a cutting template. A copy of this can be found as a PDF here.
|
|
