What are Relays used for?

I seen Relays used for Switching inputs , outputs, grounds

The relays used to Isolate the grounds how do design engineers do this?

 

Some relays are Polarized what does that mean?

 

I'm not quite sure what your current understanding of relays is... but in general, relays are either used for

1 - Switching a higher power load, than what the control circuit can supply.

or

2 - Providing electrical isolation between a control circuit and the switched load.

 

The polarized relay contain a magnet, without current give no contact.
When the coil energized with DC, one contact close, with opposite polarity
close another contact.
This relay commonly used many years ago in teletype (telex) machines.

 

This would be an exception rather than the norm.

Most polarised relays I found on the NET would held the contact in either states until changes by applying a reversing flux.

__________________
L.Chung

 

an electrical device which is activated by a current in one circuit to open or close another circuit.
a device to receive, reinforce, and retransmit a signal.

 

I seen this Design tech. take a regular preamp and eq circuit before it had no relays and then he added like 40 or more relays to do all the switching,grounding,isolation

How do you use relays to do isolation?
i think he used relays like isolation transformer

How do you use relays to isolate the ground from circuit ground from
The lighting panel grounds to run lights from the relays them self have to have another grounding so you don't hear the clicky cheater coming up from the ground

I know to use a isolation transformer to with alot of secordary isolation
terminal to use it to seperate all the grounds

How do most most design tech modify a circuit that has No relays and
then adds alot of relays to do all the switching,grounding,isolation?

The switch on the front panel would be a DC voltage going to the relay?
and the relay would handle all the switching,grounding,isolation?

 

Yes, today the original polarised relays not used.
I also know the relays as You described: i think this also called as "remanent-flux" or "adhesive" relay...
Sometimes the name depend from country

 

Whats the difference between a polarised relay and non- polarized relay

 

may i ask the obvious... what do u want to do with a relay do u actually understand what it is ? if u take a standard relay and open it up (recomend a large one for ease) u will probably get a good idea of how it works. it seems to me that u just like relays and complication and want to know how to add a bunch of relays: perhaps the technician u refered to used the relays to create a sort of switch box for multiple audio inputs to the same preamp/equalizier. he could possibly done this (depending on the situation and isolaton requirments) done the same with ICs but relays can be more easily treated as mechanical switchs as that is what they r just that they are not flicked with the hand but by an electromagnet so they r electricaly controlled switchs

__________________
I AM the exeption that disproves the rule in many ways but the rules still apply (unfortunately)

my site:www.simons-photography.com
http://rushdenrotaract.org.uk

 

I know he re-designed my friends preamps and eq's , the designer
Wraped relays around the whole preamp circuit to cut down on the wires to the front panel and did isolations, ground isolations, inputs and outputs , voltages the each relay did all this

How can i take a basic preamp circuit and wrap the basic circuit with
a bunch of relays to handles all the grounding, isolations, inputs and outputs and voltages ?

 

well as for cutting down on the wireing on the signals and hence interferance problems yes. two switch between two stereo signals a 6 or 9 (if u want to switch the GND as well but it is not always necesary) pin switchs r needed so if all this was led to a control pannel and back again then yes the rela reduced the wiring as it is activated with just two wire the power to the coil switching it on and off and controlling the complicated wireing at a distance rather than taking all the wireing to the control pannel. u r however not being that specific on what u want to do with a relay and do ur self a favour: do not do something thAT IS UNECESARY AS MORE COMPLICATED IT IS THE MORE DIFFICULT IT IS TO SOLVE A PROBLEM

__________________
I AM the exeption that disproves the rule in many ways but the rules still apply (unfortunately)

my site:www.simons-photography.com
http://rushdenrotaract.org.uk

 

Thanks for the information

a control pannel and back again then yes the relay reduced the wiring

How do i reduce the wiring on the control pannel ?

If i have a control panel with a bunch of wires and alot of switches how can i use relays to reduce the wiring and switches on the control panel?

 

it depends on where the wires come and go from. forexample if there is an input output paneland say u have two inputs being switched to one output and the in/out sockets are close together and the control apnnnels is a little distance away (this could be even like meters in some aplications) the the relay in the vicinity of the sockets and just the relay on off wire to the distant pannel will reduce the wiring it just depends on the situation

__________________
I AM the exeption that disproves the rule in many ways but the rules still apply (unfortunately)

my site:www.simons-photography.com
http://rushdenrotaract.org.uk

 

A relay gets turn on and off by a Voltage ?

So on the front control panel all the switches are just Relay voltage input switches to turn on and off the relays ?

I know the designer had the Relays Turn off certain parts of the circuit
that was not being used at that time to cut down on the Noise and make the preamp or eq's filter circuit more quiet

A Relay is a Voltage controlled switch ?
you send a pulse or voltage to the trigger input of the relay and it does the switching for you