Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Audio switching - 2PC's to 1 set of speakers

Status
Not open for further replies.

Exo

Active Member
Like the topic says, i'm trying to make a switch that lets me choose between the audio output of 2 pc's.
I intended to use the 4053 as the actual switch, but since this ic has a on resistance of about 100 ohm i will need to buffer the output...

Does anyone know a suitable buffer circuit that would allow the use of both headphones or speakers (as if they were plugged into the pc directly).
 
Why not just use a relay.

On resistance = 0 ohm
Off resistance = infinity

JimB
 
JimB said:
Why not just use a relay.

On resistance = 0 ohm
Off resistance = infinity

JimB
yeah i would use a micro relay.. they are about the size of a skinny dip wide, by same long ,and a little less than .5 in tall
 
Choose relay, because the analog switch can't handle power, it's only work with small signals. (on the input of amp)
 
No, relays are out of the question
They're modern pc's with 6.1 audio outputs, that means 7 channels to be switched per pc, and it has to be able to be switched to diffirent outputs.
It needs to be compact at the end, using relays would make it become to large...

I found an interesting chip, TDA1308 - a headphone amplifier. would it be possible to use this ic as a buffer after the cmos switches?
 
Maxim-ic have "improved" 4053 and 4066 ICs with a much lower on-resistance, but even they cannot drive a speaker directly.

What are the speakers that you are switching? Built-in amp? They must have a built-in amp if you are thinking about feeding them from the flea-power of a headphones amp.

If the speakers have a built-in amp then you don't need a buffer to follow the 4053. They will have at least a 10K ohms input impedance.
 
Yes, I know, but a pc's output allows you to connect a speaker set or use headphones. I want the output of my switch to allow the same thing.
So i need a buffer that allows me to use headphones, or connect speakers with a built in amp.
 
Exo said:
Yes, I know, but a pc's output allows you to connect a speaker set or use headphones. I want the output of my switch to allow the same thing.
So i need a buffer that allows me to use headphones, or connect speakers with a built in amp.

So use a relay!.
 
They're right, you know. A relay would be your best bet. You need to switch 7 channels, I know that sounds like a lot, but if you use DIP relays I think you'll be able to get it pretty small. :wink:

Rain

Edit: But, we might not understand your plan either. Tell me, what do you mean when you say you need to switch 7 channels? If there's 7 channels, then how exactally do the headphones hook up? By the way: https://www.allelectronics.com/cgi-bin/category.cgi?category=500&item=RLY-622&type=store That might work.
 
Electric Rain said:
They're right, you know. A relay would be your best bet. You need to switch 7 channels, I know that sounds like a lot, but if you use DIP relays I think you'll be able to get it pretty small. :wink:

Yes, if you don't want to use relays you would have to switch low level signals, using CMOS switches or similar, then have external power amplifiers to drive the speakers - which is going to be considerably large than a few small relays.

As it's a modern PC the output levels are fairly high impedance anyway, with amplifiers in the speakers (or seperate ones) - have you tried measuring the input impedance of the speakers? - it may be high enough to use CMOS switches, particularly if you can disconnect an input load resistor?.

But really a few tiny relays is simpler, more effective, and probably as small!.
 
You seem to forget the tssop smd world, i can cram all the switching i need on a 2x2 cm board.

I've tested the TDA1308 and it seems to work, so i'll be using that.
Thanks for the suggestions.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top