Recommendations for 5V relay for true bypass duties

[ElectricDruid]

Hi all,

I'm looking for a relay to experiment with a relay-bypass system. I read the Coda Effects page, and there's a couple of good recommendations on there: The Takamisawa NA05W-K or Panasonic TQ2-L-5V.

https://www.coda-effects.com/2016/04/relay-bypass-conception-and-relay.html#4

I managed to find the NA05WK on Mouser. This seems to be a Fujitsu version of the same thing:

https://pt.mouser.com/ProductDetail/Fujitsu/NA-5W-K?qs=MnnQ62GSWuG58RA8pCByRg%3D%3D

Another I've seen mentioned (by TH Custom) is the Fujitsu FTR-B4C:

http://diy.thcustom.com/shop/miniature-relay-true-bypass-kit/

Does anyone else have any favourite relays or top tips they'd like to share? I'm trying to avoid re-inventing the wheel here, and I know many of you have already done this and I'm only just now catching up.

Thanks,
Tom

[Ripthorn]

It depends a little on what you are wanting. If you do the Coda effects version of using a MOSFET to ground the signal while the relay is flipped, you obviously need a latching relay. I actually use a non-latching so that I can tie the relay coil and LED to a single MCU pin rather than using two pins for a single latching relay/LED combo. I quite like the Kemet EC2-5NU (and similar series) for their small footprint. They have worked just fine for me to date. They are also very affordable.

[vigilante397]

I just started playing with relay switching recently as I previously had no idea how easy ATTiny85 was to code, and I've ben using the NA05WK, also convenienly available at Tayda.

https://www.taydaelectronics.com/na-5w-k-mini-relay-dpdt-5vdc-1a.html

[digi2t]

I've used both. Other than the different footprint, both work equally well. It's really just a question of availability, price, and real estate.

[ElectricDruid]

It depends a little on what you are wanting. If you do the Coda effects version of using a MOSFET to ground the signal while the relay is flipped, you obviously need a latching relay. I actually use a non-latching so that I can tie the relay coil and LED to a single MCU pin rather than using two pins for a single latching relay/LED combo. I quite like the Kemet EC2-5NU (and similar series) for their small footprint. They have worked just fine for me to date. They are also very affordable.

Thanks Ripthorn.

I can see the advantage of being able to have the relay coil and the LED on one pin (paralleled presumably), and also not having to make sure the  the relay is in the same state as the LED.

You don't find that the relay coil+LED need too much juice then?

I've used both. Other than the different footprint, both work equally well. It's really just a question of availability, price, and real estate.

I thought the Panasonic TQ2-L - 5V was latching rather than non-latching? Or do you mean you've used both the Kemet EC2-5NU  and the NA05WK? Which is smaller? I don't have much space.

Thanks,
Tom

[idiot savant]

I use the Panasonic TQ2 series quite a bit, as well as the Kemet EA/EB/EC series.

Latching relays: Less power consumption overall. But, you have to manually ensure and track state in your code.

Non-latching relays: More power consumption. State guaranteed on power-up, and will auto-bypass on catastrophic power loss.

[digi2t]

The TQ2-5V (no "L" in the middle) is the non-latching version.

I've gone back and taken another look, and belay what I said about the real estate. It's 6 of one, or a half dozen of the other. Ignore the Omron in the middle, it's an SPDT. The G5V-2 is bigger still.

[bean]

The Kemet EC2 works well, 4.5v or 5v versions.
https://www.mouser.com/ProductDetail/80-EC2-4.5NU

I've used this for both DIY and production pedals.

[ElectricDruid]

Thanks all. Lots of options for me to look at there. Looks like I better go shopping...

Tom

[R.G.]

Here are some observations from working with miniature relays and uCs for a long time.

- If you're using a 5V uC and that's running things in a higher-than-9V rest of the circuit, it may well be more cost effective to use a 2N7000 out of the uC to the relay coil than to add more power to the regulator that makes 5V for the uC. It for sure makes the selection of relays bigger.
- If you're going latching to reduce the static power needs of the relay, it will be hard to keep the >clik< when whacking the relay coil out of the audio. One way that works is to put a resistor-BFC charge bucket right next to the relay so that the bolus of charge that hits the coil comes from the BFC and back to that local BFC, never getting out on the main circuit power and ground leads. It may be next to impossible to keep clicks out if you're not doing this. Er... ask me how I know this.    
- If you can, use the 10-pin low profile relays for DPDT. They can accommodate all three kinds of coils in that package, they're as cheap as the bigger ones, and they're not so high that it mucks up tight packaging.
- There is little to choose from in the manufacturers arena as long as you buy Japanese. Panasonic, Fujitsu (who is the parent of Takamisawa), Kemet, and some others are fine. I've used both Panasonic and F/T in production with no reported failures. In tens of thousands. For years.
- All of the makers make pin-for-pin replacements, as these style relays are (or at least were) used by the billions in telephone switching and they're made to allow stealing production orders from competitors by being dead-on replacements.