• 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.

On/Off Switching of Input Sources

Hymn1

New Member
I'm trying to build a simple circuit that will allow switching between multiple input sources, where the selection of one input turns off the switches of all other input sources.

I know that the traditional rotary switch has this ability, but is there a way to have standalone on/off switches for each input which then triggers all others that might be on to turn off? Is anyone aware of a on/off push button switch that has this ability? If not, a simple circuit design that can achieve the same effect?

An example of this would be in an audio store on a demo wall where a user can select a different stereo to play for comparison purposes, where only one stereo can be playing at any one time.

Any help is appreciated.
 

AnalogKid

Well-Known Member
Most Helpful Member
The action where activating one switch releases any other switches is called bailing. This can be done electronically in something called a radio button circuit (named after the action of the tuning pushbuttons in an old car radio). An electromechanical switch system for this was very popular in the 70's-80's, before high-quality analog switch chips were available and cheap.

What is the signal type (audio, video, industrial sensors, etc.)?

How many sources to select from?

electronic or mechanical action?

ak
 

Hymn1

New Member
Ohh super . . . it's audio inputs similar to the demo wall idea, but I'd prefer the switching on the 12V input power lead to the audio units rather than across the RCA outputs on those devices. I am looking at approximately 8 input sources to choose from.

Your radio button circuit is exactly the type of thing I'm trying to replicate, and I don't really mind if its mechanical or electrically triggered.
 

dr pepper

Well-Known Member
Most Helpful Member
Schadow used to make switches like that, you got the switch & the mechanism seperately, you might still be able to get them, digital electronics has pretty much made them obsolete.
You could if you have the knowledge use something like an arduino and a analogue multiplexer such as a 4052/3.
 

rjenkinsgb

Well-Known Member
Most Helpful Member
There is a ten way one in this page, the multicoloured one for £7 (third row).

There are lots of the things about on the surplus market still, it's just finding a suitable one at a sensible price!
This site in America has masses, though rather more expensive;

Or these are cheap -
 

alec_t

Well-Known Member
Most Helpful Member
This can be done electronically in something called a radio button circuit
Something like this ....
RadioButtons.png
This shows a 3-switch version, extendable to as many switches as required.
 

vu2nan

New Member
Hi Hymn1,

Here's one, using a diode matrix, push button switches and magnetic latch relays. The schematic shown is for 3 sources but it's extendable. Freewheeling diodes for the relay coils and LED indicators are not shown.

untitled.JPG

'NO' contacts of the relays K1, K2 & K3 are to be used to switch the sources.

Relays with gold plated contacts are a must considering the low level signals that are to be switched.

Regards,

Nandu.
 
Last edited:

Latest threads

EE World Online Articles

Loading

 
Top