Replacement 1st Gen Turn signal controller

[rustybronco]

What would be the easiest and quickest to produce at this point would be Mr Barr's picaxe solution.

Neither here nor there at this point. Going forward with this.

[posplayr]

What would be the easiest and quickest to produce at this point would be Mr Barr's picaxe solution.

Neither here nor there this point. Going forward with this.

Micro controller = easier

[rustybronco]

Updated the first post to reflect changes as of 04-26-14.

[posplayr]

Updated the first post to reflect changes as of 04-26-14.

That is a really old part cant find a data sheet.

PK6E22CA TVS diodes

[rustybronco]

As requested...

http://www.littelfuse.com/~/media/electronics/datasheets/tvs_diodes/littelfuse_tvs_diode_p6ke_datasheet.pdf.pdf

[posplayr]

As requested...

http://www.littelfuse.com/~/media/el...asheet.pdf.pdf

Not sure why you are using the bidirectional TVS? It has excellent ESD protection. But not sure why you need such a large parts (600W) for conducted transients. I guess they just come this size.

On the SSPB I'm using similar SMD 1500 Watt parts but that is for low impedance stuff that is hooked right to battery and alternator.

[Nessism]

Hey Jim,

What's your point with continuing to hound Dale? You said your peace so time to let it be.

[rustybronco]

Although I may disagree with Jim from time to time, I do listen to what he has to say.

Jim, if I don't know what component to use, I tend to use a bit of over kill. For example, those P-channel MOFETs are rated 27A. Very much over kill for two signal lamps that draw 2.86A.
Another example of what I'm using. http://www.ebay.com/itm/111314996551...%3AMEBIDX%3AIT ($.08 ea Vs $.19)

I really wouldn't worry to much about it as I use what I can find on the cheep even if it is overkill. I've already planned on down sizing the P-channels to FPQ17P06's which are $.65 each instead of $1.21. I found the PK6E's for $.32 each and they are rated 15kV air and 8kV contact.

[posplayr]

Hey Jim,

What's your point with continuing to hound Dale? You said your peace so time to let it be.

Ed,
That is a pretty broad brush your wielding there, I would ask "Don't you think", but obviously you don't so I'm telling you such.

I can't really know why Dale is posting schematics, but I can only gather it is to invite comment. Now while I certainly don't have the time or inclination to get involved with his design, there are some things of mild and curious interest to me and of those things I have commented.

I will not ask you to explain your intents (I presume to protect Dale), but I will tell you in no uncertain terms, that your bias to assume that I am goading, hounding or otherwise harassing Dale is a direct reflection of you own biases and not due to any actions of mine.

Jim

[rustybronco]

As there are a few members who are into electronics on this board, I did post the schematic at least in as small part to invite comments and for those who care to follow along, just see what I'm doing as the work progresses.

I may fall flat on my face with this, But it will one heck of a ride.
(I doubt I'll fail)

[rustybronco]

Additional reading material for those following along

ESD protection.

http://www.onsemi.com/pub_link/Collateral/AND8424-D.PDF

http://www.protekdevices.com/Assets/Documents/Technical_Articles/ta1013.pdf

http://www.onsemi.com/pub_link/Collateral/AND8229-D.PDF

[rustybronco]

Not sure why you are using the bidirectional TVS? It has excellent ESD protection. But not sure why you need such a large parts (600W) for conducted transients. I guess they just come this size.

It appears the DO-15 package TVS's only come in the higher wattage values.
The bidirectional was to protect from possible induced A.C. voltages from the ignition coils or if someone ran an electric motor such as a drill next to the TSCU.

I've been sensitive of it since the time I used a corded drill next to my car (which was equipped with an aftermarket remote start) and the vehicle cranked every time I pulled the trigger.

[posplayr]

It appears the DO-15 package TVS's only come in the higher wattage values.
The bidirectional was to protect from possible induced A.C. voltages from the ignition coils or if someone ran an electric motor such as a drill next to the TSCU.

I've been sensitive of it since the one time I used a corded drill next to my car (which was equipped with a aftermarket remote start) and the vehicle cranked every time I pulled the trigger.

I was going to dig out that first reference. You would be better with the unipolar. It still provides the protection you want. In that ap note they basically explain that bipolar relates to the valid voltage ranges of the signal you are trying to pass, not the bipolar surge. In the SSPB all tvs's are unipolar all voltages are 0-12v.
Off hand the only bipolar signals are the stator a/c and ignitor waveforms.
I understand about the surges much more now; look up automotive "load dump". I'm not sure you need to worry about it for this but for the SSPB it was a driving issue.

[rustybronco]

You would be better with the unipolar. It still provides the protection you want. In that ap note they basically explain that bipolar relates to the valid voltage ranges of the signal you are trying to pass, not the bipolar surge.

I did see that in the notes and have been trying to read as much as can on the subject (among other things). I already have been considering the change to a uni-polar particularly because of this statment...

A unidirectional TVS is best suited for protecting circuit nodes whose signals are unidirectional or always above or below the reference
voltage, usually ground.

I already made one design change from the LM556CN to a NA556N because the LM is only rated 0° to 70° C. The NA556 is rated -40 to 105° C. I really would have loved to have found one that was rated at 150° but I'll take what I can get.

[rustybronco]

Drilled out and used a die grinder in an attempt to remove the epoxy(?) potting material so duplicates (or similar) could be made of the housing. This is now going to require a project box.
There's no way to save the old housing for reuse or duplication.