Best Relay

[audiomick]

8 hours ago, audiomick said:

 The "vibration resistance" spec

Regarding that: the spec. sheets refer to 10 ~ 40 Hz. . I thought that was probably to low to be relevant, but it turns out I was wrong. 2.4000 rpm is equivalent to 40 Hz, i.e. 2400(rpm )/ 60(seconds per minutes)=40 (Herz=cycles per second). So the stated frequency range is relevant to the lower part of the real world rev. range of the motor.

 

Apart from that, other pennies have been dropping in the course of today. Regarding the coil resistance, which I hadn't done all that much till now: coil resistance is tied up with coil power, which docc has mentioned a couple of times.

The corelation is in the formulae. Coil power can be calculated with the formula P = VI

https://en.wikipedia.org/wiki/Electric_power

and the current in the coil with I=V/R

https://en.wikipedia.org/wiki/Electric_current

The Picker spec. sheet quotes coil resistance at 120 Ohm for the 1.2 W version, as does the spec. sheet for the CIT relay. That gives us a current in the coil of 12V divided by 120 Ohm = 0.1 Ampere. So, negligible.

Therefore I would assume that the coil power (apart from holding the relay open/closed under mechanically difficult conditions like excessive vibration) or coil resistance (looking at it from the other side) is pretty much irrevlevant. Mechanical switches such as the ignition switch, light switch, and so on, can certainly handle that sort of current.

 

The exception might be the relay that is switched by the ECU. The switching voltage is generated by the ECU, a solid state circuit (i.e. probably a transistor). Such things are set up to expect a specific resistance at the othe end of the wire. If the resistance at the other end is too high, not enough current can flow (I=V/R, and V is constant). If the resistance is not high enough, too much current could flow, and the output stage of the ECU might shit itself.

Therefore, I would not like to see the coil resistance /coil power for the specific relay that is switched by the ECU deviate to much from the specs of the original relay.

Otherwise, I think that (coil resistance) is a spec. that doesn't have to interest us too much.

[docc]

The coil wattage/power on these "Relays of Interest" has ranged from 1.2W to 1.5 to 1.8 (that highest on the NLA OMRON G8HE unicorn relays).

Is the difference negligible in our practical application? Unknown. Someone knowledgeable suggested that the higher the coil power, the more tightly the N.O. contact is held (I paraphrase) for a potentially higher amperage contact rating and less chance of "bounce."

Given the option, I would choose a higher coil power. That said, I am running a couple 1.2W CIT in the least critical positions (#3/Neutral and #4/ECU).

The details and minutiae of this discussion fascinates maybe two or three of us.

The rest just want to know what one relay to plug into all five positions and forget about them. Worry more about beer.

[Speedfrog]

2 hours ago, audiomick said:

The Picker spec. sheet quotes coil resistance at 120 Ohm for the 1.2 W version

The Picker 1C for our application has a coil power of 1.5W with a resistance of 96 ohms @ 12V. 

1 hour ago, docc said:

The rest just want to know what one relay to plug into all five positions and forget about them.

You got that right! That's an awful lot of ink for a $2.50 part... It all depends how much you value your time, ROI and all that.

I'd say, get a baker's dozen, carry a couple of spares under the seat and fuhgeddaboudit

2 hours ago, docc said:

Worry more about beer.

And ride the damn bike....

[docc]

1 hour ago, Speedfrog said:

Ok, let’s drift....

 

I see a "Banter thread" coming out of this.

"Watch" for the posts to split . . .

 

[audiomick]

On 4/5/2023 at 3:40 AM, docc said:

The details and minutiae of this discussion fascinates maybe two or three of us.

Yes, I know. I can see people's eyes glazing over as they read from here.

Nevertheless, a quick word about coil resistance and power. I spoke once again to my electronic technician colleague. He confirmed that a solid state circuit providing the voltage to activate the coil of a relay would indeed be set up for a specific resistance, but the tolerance is likely to be very high. As long as the replacement has a resistance "in the same order of magnitude" it should be fine.

He also confirmed the importance of a strong contact, particularly in a high vibration environment like in a motorcycle. Therefore docc's preference for a "stronger" coil is justified.

[docc]

The only relay coil being activated by a solid state circuit is the #5/Fuel-Ignition relay. I have run 1.8 watt and 1.2 watt coils in that position for extended periods of time (years) with no issues. So, it seems the 1.2-1.5-1.8 watt coil range checks out in that regard.

With regard to vibration and "bounce", it makes sense to choose a higher coil wattage for the N.O. contact.

The only place I have had intermittent contact ("bounce") is the N.C. (weaker, spring dependent) contact on Relay#1 (SPDT/5-pin) from a damaged relay. I like the 25 amp N.C. Picker Components option for this position on the early 1999-2001 Sports/Rosso Mandello that send all of the power to the N.O. contacts of the "Headlight etc." Relay/ #2. Later N.C. relay #1 only pull in the #2 coil, but I still wouldn't want it to "bounce."

[audiomick]

1 minute ago, docc said:

.. but I still wouldn't want it to "bounce."

Quite rightly. Regardless of how much current is going through the contact, if it starts bouncing there wil be "constant" arcing across the contact. That is, over time, the end for the relay.

[docc]

3 minutes ago, audiomick said:

Quite rightly. Regardless of how much current is going through the contact, if it starts bouncing there wil be "constant" arcing across the contact. That is, over time, the end for the relay.

Brings me full circle to say that best practice on our V11 is to simply run the same high-current (5-pin) relay in all five positions. As of April 2023, this looks like the best candidate (likely available worldwide):

Picker Components PC782-1C-12S-R-X (avaiable from DigiKey)

Datasheet

And, yes, as @Speedfrog says, "$2.50US, each" . . .

[audiomick]

The only thing that gives me cause to stop and think is the height at 26mm. I gather the originals were 21mm. The ones in mine at the moment are 22mm. .

 

Has anyone got the Picker items in a V11, and can comment on the clearance to the seat or lack thereof?

[gstallons]

Get some Play-Doh or something similar and yse it to check for clearance . 4mm is not much difference

 

[docc]

40 minutes ago, audiomick said:

The only thing that gives me cause to stop and think is the height at 26mm. I gather the originals were 21mm. The ones in mine at the moment are 22mm. .

 

Has anyone got the Picker items in a V11, and can comment on the clearance to the seat or lack thereof?

The taller relays have been in mySport many years (twenty?) with no problem. I currently have the Picker in Position #1.

Seat pans varied over the model range, so gstallons' clearance check is good method.

[audiomick]

4 hours ago, gstallons said:

4mm is not much difference

The difference between "clearance" and "no clearance" is less than 1 mm.

But the tip is good. I'll see if I can measure the clearance somehow. I'm thinking of it because one of the bolts holding the relay sockets to the frame doesn't have any clearance.

[gstallons]

Hmmmm. IDK what is going on uner the plastic cover that is worth the extra length ? 1 mm is pretty close !

[LowRyter]

I was playing musical relays today  ...usually reseating works.  I got home and cleaned everything with Deoxit and some generic cleaner just to be sure.  Those little boogers were pretty hot to the touch.  Anyway, one of those Omcons was a failure. It was didn't work wherever I plugged it in.   Despite cleaning the prongs pristinely. 

I had a stash of dirty little-bitty Siemins in a little paper box in the tankbag.  I probably took them off the Cali as I think I originally had Bosch in the Greenie.  Fixed the problem for now.

I'm a little concerned about Omcons now.  I think that was my first confirmed relay failure for nearly 90k Guzzi miles.  Perhaps some of my "connection" issues might be these little black cubes?

[docc]

What position did the damaged OMRON come out of?

That could be an indication of a connection issue on that circuit causing voltage spikes. Most especially, damage to the yellow output wires at the stator can destroy the regulator and relays.