Voltage regulator for electronic ignition?
 

Anyone try or have a suggestion on a type of voltage regulator for electronic ignition modules? I want to get away from using Nicads and such and start using Life or A123 types. Problem is the ignition modules I have on some engines are 6volt max and I don't want to risk ruining or burning one out. Life type batteries are 6.6 volt and will reach over 7 volt when charged. I've seen some like Mpi that are rated 5amp and up to 10 max. But they are not cheap. Also seen some from HK that are much cheaper and run 5 amp to about 71/2 max. Not sure if these are the correct things to be using. Any thoughts? I need to get quite a few of them.

Stick with the Nicad for the ignition. Works the best. Then set up the receiver and servos with the A123 or LiFe battery. I use a regulator on my receiver and set it to 5.2 volts output.

I have never used a regulator for ignition but have heard of some problems with certain brands and types of regulators. The problem seems to be the pulsing nature of the ignition. Though the average current requirements are low, the ignition module requires a fairly high current for a very short period of time for each spark cycle. If buying a regulator, I'd check closely with the mfgr. to make sure it was suitable for this application.

Many of us have eliminated the ignition battery completely by using something like the very reliable TechAero Ignition Battery Eliminator Circuit .. IBEC. These are in very wide use now and offer features such as selectable voltage output, peak current limiting, power isolation from the receiver battery, ignition cut-off from the transmitter, etc. just to name a few features.

Some people still don't trust running the ignition off the receiver battery but many others such as myself find they work excellent and actually reduce the number of possible failure points in the circuits. Check them out here .....

http://www.tech-aero.net/ultra-ibec

+1

Thanks for the replies, I run all my planes on A123 or Life packs and did away with Nicads long ago with the exception of the ones with electronic ignitions. The IBEC is a interesting concept, but on this particular project I'm running 4 engines and don't want to be running 6 foot leads up and down the wings. Also I don't know if one IBEC could handle 4 ignition modules. I supposed Nicad packs would be the cheapest route in this case.

You would probably need (4) IBEC. One at each engine. You could power them all from one source though you might not want to use the receiver battery in this case.

I run LIFE batteries on both receiver and ignition. For the older ignitions I use a simple diode in the lineto reduce the voltage. A single diode will drop the voltage by 0.7 volts. I have no problems with a single diode on ignitions rated for 6 volts.

There is a double diode available that I thought would be a good idea, as it would provide electrical path redundancy. But I can't remember the part number for it. Anyone know?

AV8TOR

I've run the 5 amp HK regulators on ch ignition with no problems.

Jerry

wrongway rc sells an inline diode. Single diode for A123's and double diode for 2s LiPo

www.wrongwayrc.com

That's all you need, you don't need a regulator.

A123's work great on ignitions.

EDIT: http://www.wrongwayrc.com/index.php?...product_id=154

Yeah, a double inline diode, (series) would decrease the voltage by about 1.4 volts. What I meant was a double side by side (parallel) diode. That would provide for a backup path for the current if one diode happened to fail. There's one out there, I just can't find the post that referred to it and gave the part number for it. Of course a person could just wire in two diodes, but I thought the double diode was rather neat and easy to use.

AV8TOR

I am using a Bridge rectifier and they work great for my Li-Ion batteries. I have a tutorial that was posted here on RCU if wanted.

Yes, I would like to read that.

Thanks,
AV8TOR

I have been using Wrongway RC's diode on ignitions with LIFE packs for several years with no problems. A simple solution to the O.P's question.

I'm using the HK 3amp regulator with Life batteries. I've been doing this for a year and now have three planes equipped the same way. No problems, yet. Using with the ignitions that came with DLE and RCGF engines. Only uses about 60-70 ma per flight.

Apparently I can't load it so here is a link to the article/how to. http://pages.suddenlink.net/arlyn/rcvotagedrop.html

I prefer the simplicity of a couple of diodes, and place them right in the output leg of the opto switch. 5 minutes and 2 50 cent Radio Shack diodes (1N4007) will get the job done. Properly chosen, there's no capacity issue, and I've never heard of one failing for any reason.

Of note, either way you go, diodes or bridge, when you're done and testing, the circuit must be live, under load. Otherwise you'll get wacky voltage readings for sure!

Thanks Ace!
AV8TOR

If I were building an airplane with 4 gas engines I would run 4 Tech Aero IBEC units. Reason being is that they can all be driven off the same channel so if needed you can shut down all 4 engines at the flick of a switch. You would also be able to run 2 redundant RX packs of whatever chemistry you desire and that's all. I know you expressed the desire to not want to run wires through the wing but if you think about it, wouldn't that be better then running a separate battery in each nacelle?