Signal relays.

[bikerhifinut]

Hope I have the correct section of the forum.

My query is this:

Is all I need to utilise a fairly standard low current 5V relay to switch signal sources a switched power source and a protection diode across the relay solenoid?
Looks a fairly easy task if that's the case.

I know that there's a very good relay switched socket solution from WD but in my particular application I don't need all the functions the board needs, and I have a nice remote switched mute function off the HFC remote control board.
So I thought 5 DPDT 5V relays with silicon diode protection would fit very well on a bit of perforated stripboard as they are the same pin pitch as a 16pin DIL device. In fact I considered the idea of a socket until I realised it could compromise the audio signal perhaps.
I am happy with the extended spindle solution for the selector switch and it would cost about the same to purchase a higher quality switch, but until I get the Aikido CF PCB I won't know if the switch shaft will clear the components on the board.
I was looking at relays with gold plated silver contacts, they are tolerant of voltages up to 7.5V so will work fine off the heater supply. Current draw around 30mA so shouldn't be an issue.
I did see another advantage in that the relay switches could short the inputs to ground when not selected, thus eliminating any crosstalk?
Anyone see why I shouldnt do this?

Andy.

[bob orbell]

That is just the same as the WD PREIII relay input Andy, I take it your heater supply is DC.

[bikerhifinut]

Yes DC. I currently have a standard PSU3. The new PSU Board when it comes will also have regulated DC heaters so I have no worries there.
Looks like I got nothing to lose by this. So I'll order up a quintet of relays and some diodes.

Ta Bob.

A.

[John Caswell]

Hi Andy,
Be careful when you buy the relays that they do not have a diode internally which can be confusing. Diodes use a 1N4148.
Sealed PO approved relays are excellent choices, and are cheap from RS/Farnell/CPC, yes do fit them in sockets, they are an electromechanical device and will likely be the first thing to fail, and it makes life easier for wiring, I use stripboard for mine and support the whole thing off of the phono sockets with 18 or 22swg wire.
You do not need a poncy switch to operate them it is only DC you are switching anything will do.
If you get the DPCO/DPDT (double pole changeover/double throw) type of relay then it can be arranged to short the unselected inputs to ground as you say, works a treat!

John