SDS CDI vs Pmag

[Tomcat RV4]

The color SURE don't effect the great service or quality ! Tom

[bigwheel]

Ross, I must apologize. I certainly didn't mean anything negative towards SDS. I recognize how quickly the electronics world evolves and I was just laughing at how this always happens to me. I'm sure GRT will release a new EFIS/EIS in a few months...right after I purchase a system

I look forward to learning about the CPI2 and maybe I'll install it rather than buying a second CPI module (I'm installing a single module dual coil system as a stepping stone into the EI world).

[rv6ejguy]

Originally Posted by bigwheel

Ross, I must apologize. I certainly didn't mean anything negative towards SDS. I recognize how quickly the electronics world evolves and I was just laughing at how this always happens to me. I'm sure GRT will release a new EFIS/EIS in a few months...right after I purchase a system

I look forward to learning about the CPI2 and maybe I'll install it rather than buying a second CPI module (I'm installing a single module dual going system as a stepping stone into the EI world).

No worries, I didn't take any offence to your comment, it's happened to all of us. One other guy asked why we'd announce this so early and possibly hurt current CPI sales. We like to involve our customers in the design process as we end up with a better product appealing to a wider market in the end. As on the EM-5, many of the best new features on it were suggested by existing clients using earlier versions.

[Chkaharyer99]

Ross,

Will the new CPI2 have the LOP Switch located on the CPI2 device or will it (LOP Switch) need to be panel mounted?

Will the CPI2 have a provision for 1 power source or 2?

Thank you,

[rv6ejguy]

We're trying to move away from external switches on the new design, have to see how that goes.

We were discussing power backup in depth this afternoon during a brainstorm session.

1: Optional backup power for one CPI and its coil pack

2: Optional backup power for two CPI and both coil packs

Do both CPIs and coil packs share a single backup battery or have separate ones?

Do we allow charging the backup battery from the main bus or keep totally isolated?

We want to have useful capability and function without excessive complexity and cost. This usually means design simplicity.

[tspear]

Originally Posted by rv6ejguy

We're trying to move away from external switches on the new design, have to see how that goes.

We were discussing power backup in depth this afternoon during a brainstorm session.

1: Optional backup power for one CPI and its coil pack

2: Optional backup power for two CPI and both coil packs

Do both CPIs and coil packs share a single backup battery or have separate ones?

Do we allow charging the backup battery from the main bus or keep totally isolated?

We want to have useful capability and function without excessive complexity and cost. This usually means design simplicity.

In the IT space, usually simplicity for the customer means complexity for the developer.
My suggestion (taken from data center computers):

• Each coil has dual power inputs, one is primary the other is backup. If primary does not work, it auto fails over to the backup.
• Each cpi has dual power inputs, one is primary the other is backup. If primary does not work, it auto fails over to the backup.
• Via the CPI/Ignition cable, the CPI is notified of power failures. CPI can then pass up the chain.
• Each CPI is cross connected to the opposite coil. If a coil does not have standby power coming from the primary CPI, it auto switches to the second CPI.
• In terms of charging, I like solutions like this one: https://www.bluesea.com/products/760..._12_24V_DC_65A
  Allows you so have multiple batteries charge off a single bus.

Is that over engineered enough? Really simple for the customer, painful for you.
The customer can then chose to have serial separate systems, or just by adding a cable provide point system redundancy at either the CPI and/ot the coil.

Tim

[rv6ejguy]

All food for thought. Thanks Tim.

[Chkaharyer99]

Originally Posted by rv6ejguy

We're trying to move away from external switches on the new design, have to see how that goes.

We were discussing power backup in depth this afternoon during a brainstorm session.

1: Optional backup power for one CPI and its coil pack

2: Optional backup power for two CPI and both coil packs

Do both CPIs and coil packs share a single backup battery or have separate ones?

Do we allow charging the backup battery from the main bus or keep totally isolated?

We want to have useful capability and function without excessive complexity and cost. This usually means design simplicity.

As I look at the SDS "Dual CPI Wiring" diagram, Revision 1.0, dated January 17/17, I see a few things that you might consider for removal from the aircraft panel and integrate into the new CPI2 architecture, specifically:

1. LOP Switch
2. Coil Pack 1 Switch
3. Coil Pack 2 Switch

Q1: Do both CPIs and coil packs share a single backup battery or have separate ones?

A1: Maybe it could be designed and built in such a way that this could be a user decision and configured accordingly and easily with a jumper. The options could be: a.) No backup battery. b.) One back up battery for one CPI/coil pack. c.) One back up battery for both CPI/coil pack. d.) Two back up batteries. One for each CPI/Coil pack.

Q2: Do we allow charging the backup battery from the main bus or keep totally isolated?

A2: Consider making it consistent with how EFIS MFG are doing it. Or, this could be a user decision and configured accordingly.



I have two Slick mags that are approaching rebuild time. I started out wanting electronic ignition for the obvious benefits it provides. Early on, I leaned towards Pmags because they are very easy to install. They do, however, have their limitations. I will not go into it here.

I want the ability to change my timing, not just my curve, for specific RPM and MP. I prefer the ease in which the SDS CPI allows the operator to do that. By integrating some of the components on the "Dual CPI Wiring" diagram into your proposed new device, you add complexity on your side but subtract it on my side. You might also be able to design in even more reliability by removing potential points of failure currently depicted on the user side of the wiring diagram.

[rv6ejguy]

It's a priority to try to remove the external LOP switch for sure.

There's currently an internal function to do a "mag check". We'll carry that over to the new design.

There may be instances where people want to shut off coil power. If we internalize that, people would not easily have that option. These are all things we need to weigh.

Our intention is to provide a vendor designed option for emergency backup power (complete with battery, relays and mounting tray)to those who want it. People who already have or want to design their own setup could skip our solution and use their own.

We don't mind taking longer to design the CPI2 to be less complex for the user but we generally don't believe in design complexity and adding more points of failure for perceived risks which are minute in real-life. Components which are not there, can't fail.

Our products are made to order for each customer. This includes coil mounting, options and wiring harnesses. When it comes to activating options, some are done with jumpers, others in software. We make this stuff easy to change for ourselves or customers.

We have to remember that this keeps the engine running or not, arguably more critical than glass displays. If battery charging isolation gives us less chance of taking down the ignition, we'd go that way. If we can find a super reliable way to charge the backup battery (BB) and still have super reliability against all considered faults, we'd go that way.

When it comes to wiring engine electronics, at some point, excellent power and ground connections have to be made to the aircraft. That's something nobody can control except the installer and in our experience, those are the #1 causes by far of the electronics going down.

99% of the stuff sent back to us which "does not work" either does work just fine (indicating a user wiring issue) or got very wet.

Keep the input coming. We'll try to consider and implement all the good ideas.

[flyboykelly]

Originally Posted by rv6ejguy

Looking for customer feedback on any additional features people might want.

We'll offer 4, 6 and 8 cylinder systems as we do now. They will all be released simultaneously so no waiting for a 6 cylinder system...

7 and 9 cylinder!?!?