Relays

[wizard333]

Curious what folks are using or suggestions for the following:

Relay that can work off rectified heater AC (so +/-3vDC), small footprint, reliable, not noisy (coil supply ripple not inducing hum in the audio pins), fast, sonically transparent, etc.

Switching pre-amp audio signal here not power supply voltages or anything like that so power handling doesn't have to be high.

Thanks!

[SysCrusher]

Curious what folks are using or suggestions for the following:

Relay that can work off rectified heater AC (so +/-3vDC), small footprint, reliable, not noisy (coil supply ripple not inducing hum in the audio pins), fast, sonically transparent, etc.

Switching pre-amp audio signal here not power supply voltages or anything like that so power handling doesn't have to be high.

Thanks!

I use a 3v relay.

EA2-3NJ NEC Low Signal Relays - PCB

Some 5v relays have a 3v turn on but that is a hit or miss thing.

[wizard333]

No one else uses relays?


I've aways used 5v relays but sadly the ones I used are labeled "obsolete" now, and to be honest they werent that fantastic anyway. I was hoping there was some new and better option.

You don't have trouble with overloading the coil on 3v relays? How long have you had them in service?

[defaced]

Omron G5V series relays are very popular for this application. 5v versions are available so use your standard heater power supply you've been using.

[wizard333]

I looked the Omrons up and found 2 potential 5v candidates:

G6A-274P-ST-US-DC5 Omron Electronics Low Signal Relays - PCB

G5V-2-DC5 Omron Electronics Low Signal Relays - PCB

The G5vs are significantly cheaper but the G6As have low magnetic bleed and are smaller, which I like. Which are you using?

Any benefits to high sensitivity vs std etc?

At the bottom of the data sheet there was this disclaimer:

"Long-term Continuously ON Contacts
Using the Relay in a circuit where the Relay will be ON continuously
for long periods (without switching) can lead to unstable contacts
because the heat generated by the coil itself will affect the insulation,
causing a film to develop on the contact surfaces. Be sure to use a
fail-safe circuit design that provides protection against contact failure
or coil burnout."

Which makes me wonder about long term reliability if used in channel switching because the "charged position" channel may be left on quite a while. Have you had any problem with long term reliability?

[Hardtailed]

Any benefits to high sensitivity vs std etc?

High-sensitivity = less power required to switch it

I see two advantages
- Less current going through your footswitch cable
- Less stress on your power transformer (which is already busy powering the filaments)

Although, there are even higher sensitivity options
This one is 40mA for 5V, but I see this Panasonic is a mere 28.1mA:
Panasonic TX2SS-5V
And it's cheap too

[SysCrusher]

No one else uses relays?


I've aways used 5v relays but sadly the ones I used are labeled "obsolete" now, and to be honest they werent that fantastic anyway. I was hoping there was some new and better option.

You don't have trouble with overloading the coil on 3v relays? How long have you had them in service?

Happily moving along for the past year. Never a problem. Most relay coils are rated for a maximum voltage that is pretty generous. You could always throw a resistor in series before the coil if you needed too. I don't use a bridge but a full wave rectified to end up with 4vdc, so I look for the 3v relays. I avoid any ground loops doing it that way. I could use a full wave bridge for more voltage and float the other negative end but then I'm using 2 more wires. Most effects units come with a relay switcher that will only switch one lead to switch channels on your amp.

[defaced]

I looked the Omrons up and found 2 potential 5v candidates:

G6A-274P-ST-US-DC5 Omron Electronics Low Signal Relays - PCB

G5V-2-DC5 Omron Electronics Low Signal Relays - PCB

The G5vs are significantly cheaper but the G6As have low magnetic bleed and are smaller, which I like. Which are you using?

Any benefits to high sensitivity vs std etc?

At the bottom of the data sheet there was this disclaimer:

"Long-term Continuously ON Contacts
Using the Relay in a circuit where the Relay will be ON continuously
for long periods (without switching) can lead to unstable contacts
because the heat generated by the coil itself will affect the insulation,
causing a film to develop on the contact surfaces. Be sure to use a
fail-safe circuit design that provides protection against contact failure
or coil burnout."

Which makes me wonder about long term reliability if used in channel switching because the "charged position" channel may be left on quite a while. Have you had any problem with long term reliability?

I use the G5Vs, and have seen them used, in high gain circuits (four stages + CF) and have not had a problem with the coil interfering with the signal. Remember, this is DC, so ti's less likely to couple to the signal. http://music-electronics-forum.com/t11093/

As for voltage and high sensitivity, I use 24v high sensitivity relays because they are part of an elaborate MCU switching circuit I'm designing that benefits from low current draw. 24v high sensitivity G5Vs need something like 8ma to operate, and that's what I'm looking for. I would just be mindful of your heater winding current rating and choose and relay sensitivity that's appropriate. I don't think you can go wrong with the high sensitivity kind because they have lower current requirements and are the same/similar price as the regular ones. I wouldn't over think this too much.

As for the long on time issue, it depends on what "long term" means. In the world of electronics, I wouldn't call 2-4 hours long term, but that's doesn't mean they don't. I have not had a problem with them.