Rca source selector using relay

[burrow]

Hai , i was making an A/V selector switch that will be controlled my microcontroller.
I will be using SPDT relays each for Video, left ,and right.

The NO and NC contact of relay will go to 2 different sources. So my question is will this configuration give out any sort of noise (because inside the relay the contacts might be close so will they interfere )

also can i tie grounds of all sources together or should i go for a relay for selecting ground too ?

 

[D.A.(Tony)Stewart]

It will make a pop without expertise on EMI control.

Even if you put a reverse diode across the coil, it will still resonate 0.7V with the diode Then an RC cap wil cause another pop charging it up, so you need ferrite CM choke. Chance of CM leakage hum from multiple sources is high.

But then you can pick up 4 way AV switches in a bazarre or garage sale or off the web for $20.

Switching grounds is not worth it.

They use CMOS switches these days or perhaps Reed Relays for purists. Tie all Reeds to output and select each one with a slide or rotary switch 20mA.

Since Video is 75 Ohm, small area and shielding is necessary,

Why dont you get a HDhomerun router OTA digital tuner for roof antenna and switch Applications and connect all TV to PC unless you want live cricket...on cable then use TV as the AV switch.

 

[BigBoss]

Hai , i was making an A/V selector switch that will be controlled my microcontroller.
I will be using SPDT relays each for Video, left ,and right.

The NO and NC contact of relay will go to 2 different sources. So my question is will this configuration give out any sort of noise (because inside the relay the contacts might be close so will they interfere )

also can i tie grounds of all sources together or should i go for a relay for selecting ground too ?

Are you using standard mechanical relays for Audio and Video signals ??? If it's so, you're making a big mistake.If I were you, I'd use solid state particular A/V switches.
Solid-State relays which are used for Audio and Video switching don't produce any significant noise and you should use them for this purpose.
Videos GND and Audio GND shouldn'tbe tied together other wise Video GND path will distrub/soil Audio GND path.Every source will be terminated its dedicated load.