Hi Everyone,
I'm hoping someone can help me find the right part. I'm looking for essentially a SPDT switch suitable for line-level audio that changes position when the 12V from a trigger source (like a HT processor) is on.
The idea is that I have an amp and I want it to switch from the 2-channel preamp to the HT processor when the HT turns on. When the trigger is off it should revert to the 2-channel preamp outputs. I have other things I am doing too, but this is basically it. Ideally solid state, zero impedance. I seem to remember at some point finding an ideal part via Mouser or Digikey but long ago lost to me.
In addition, would like it to draw as little current as possible when activated, and of course, this is line level audio so near zero current in the signal itself.
Thank you,
Erik
I'm hoping someone can help me find the right part. I'm looking for essentially a SPDT switch suitable for line-level audio that changes position when the 12V from a trigger source (like a HT processor) is on.
The idea is that I have an amp and I want it to switch from the 2-channel preamp to the HT processor when the HT turns on. When the trigger is off it should revert to the 2-channel preamp outputs. I have other things I am doing too, but this is basically it. Ideally solid state, zero impedance. I seem to remember at some point finding an ideal part via Mouser or Digikey but long ago lost to me.
In addition, would like it to draw as little current as possible when activated, and of course, this is line level audio so near zero current in the signal itself.
Thank you,
Erik
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So this seems ideal, even though it's actually mechanical:
https://www.mouser.com/ProductDetail/CUI-Devices/SR5-12V-200-1C?qs=4ASt3YYao0WMNY1cu6cO0A==
https://www.mouser.com/ProductDetail/CUI-Devices/SR5-12V-200-1C?qs=4ASt3YYao0WMNY1cu6cO0A==
1 - are you switching from 2 ch pre-amp to 2 ch HT?
This would need DPDT signal relay.
3 - I expect you would need a transistor driver for the relay to isolate the HT trigger from the relay; assuming the HT trigger is not actually meant to deliver any current. Look up circuits for driving a relay with an Arduino to get the idea and note protection diode for protection from inductive spike from the relay coil. If building the switcher as a stand alone unit, power from an old phone charger (5V charger & relay).
I don't have HT but have done similar relay switching.
When you have figured how you intend to go, post your plans.
This would need DPDT signal relay.
3 - I expect you would need a transistor driver for the relay to isolate the HT trigger from the relay; assuming the HT trigger is not actually meant to deliver any current. Look up circuits for driving a relay with an Arduino to get the idea and note protection diode for protection from inductive spike from the relay coil. If building the switcher as a stand alone unit, power from an old phone charger (5V charger & relay).
I don't have HT but have done similar relay switching.
When you have figured how you intend to go, post your plans.
I am going from a 5.1 ch receiver with pre-outs, but I only need to switch the L and R outputs. All the other channels are driven from the HT. I realize that I'll need two of these relays, I'm thinking that this is a good choice for the sake of maintaining maximum channel separation.
The relay I found takes about 16mA to turn on, I'm waiting on the specs for the 12V trigger outputs, but even if it only supplies 50mA that should be good enough for both relays. If it takes more than that I'll consider some sort of protection scheme. I think these relays sound really low power and won't need one.
The relay I found takes about 16mA to turn on, I'm waiting on the specs for the 12V trigger outputs, but even if it only supplies 50mA that should be good enough for both relays. If it takes more than that I'll consider some sort of protection scheme. I think these relays sound really low power and won't need one.
Just make sure to put a diode (1N4007 for example) across the relay coil so the flyback of the relay coil doesn't fry the trigger output. The cathode of the diode should be on the (+) side of the relay coil. Also note that some relays have polarized coils. They seem to have a small magnet inside to help them draw fast at low current. Check the relay data sheet for the polarity.
Tom
Tom
I would probably just mix both inputs (resistors), maybe mute the unused input. A simple JFET shunt works well. But unless the unused source is noisy, there is no need to mute it, and no power supply is required.