From: Peter Hill on
On Sat, 5 Jun 2010 14:01:02 -0700 (PDT), denali
<007denali(a)comcast.net> wrote:

>On Jun 5, 12:28�pm, PeterD <pet...(a)hipson.net> wrote:
>> On Sat, 5 Jun 2010 14:36:08 +0100, "ian field"
>>
>> <gangprobing.al...(a)ntlworld.com> wrote:
>> >Since other people have started posting car electronics questions, I thought
>> >I'd strike while the iron is hot so to speak.
>>
>> >Anyone got tech info on the Lucas 9EM ignition module?
>>
>> >Thanks.
>>
>> What is it out of, what does it do?
>
>As with all components manufactured by Lucas, the God of Darkness,
>it's purpose is to function for a non-specified length of time and
>then fail at the most troublesome moment.

Bosch have taken up the challenge.

Igniton unit failure takes out coil as it fails short so overheats
coil. Coil failure takes out igntion amp by short circuit. Which comes
first? They all do that sir.
--
Peter Hill
Spamtrap reply domain as per NNTP-Posting-Host in header
Can of worms - what every fisherman wants.
Can of worms - what every PC owner gets!
From: ian field on

"Jim Yanik" <jyanik(a)abuse.gov> wrote in message
news:Xns9D8EC697D63A5jyaniklocalnetcom(a)216.168.3.44...
> "ian field" <gangprobing.alien(a)ntlworld.com> wrote in
> news:_OxOn.60834$BW1.22398(a)hurricane:
>
>>
>> "PeterD" <peter2(a)hipson.net> wrote in message
>> news:bb9l06dksa9gmiu63a5cee8h6bna0rvv02(a)4ax.com...
>>> On Sat, 5 Jun 2010 14:36:08 +0100, "ian field"
>>> <gangprobing.alien(a)ntlworld.com> wrote:
>>>
>>>>Since other people have started posting car electronics questions, I
>>>>thought
>>>>I'd strike while the iron is hot so to speak.
>>>>
>>>>Anyone got tech info on the Lucas 9EM ignition module?
>>>>
>>>>Thanks.
>>>>
>>>
>>> What is it out of, what does it do?
>>>
>>
>> It was widely used on British cars, during the 80's IIRC.
>>
>> Its a transistor assisted ignition, but I don't know whether its
>> points or reluctor.
>>
>> A couple turned up in a box of auto spares I aquired and it'd be handy
>> to figure out how to test them..
>>
>>
>>
>
> open one up and examine it. Or is it potted?

Its potted and backed with an aluminium h/sink plate - notoriously difficult
to abrade the filler away without destroying the components.


From: ian field on

"Dave Plowman (News)" <dave(a)davenoise.co.uk> wrote in message
news:5122d92b1cdave(a)davenoise.co.uk...
> In article <_OxOn.60834$BW1.22398(a)hurricane>,
> ian field <gangprobing.alien(a)ntlworld.com> wrote:
>> It was widely used on British cars, during the 80's IIRC.
>
>> Its a transistor assisted ignition, but I don't know whether its points
>> or reluctor.
>
>> A couple turned up in a box of auto spares I aquired and it'd be handy
>> to figure out how to test them..
>
> I don't think Lucas ever made assisted points systems and all the
> electronic ones I know are VR.
>
> I think the unit you refer to was mounted on the distributor, and the most
> likely vehicle it was used on in the US the Range Rover. The connections
> on the heatsink or mounting plate are to the VR sensor, the other two on
> top go to the coil. Some later versions had a three pin connector - the
> extra one for a cable shield.
>
> The unit can be reliable but rather depends on how hot it gets. On
> vehicles with air con it's likely to have a shorter life.

Thanks - that's more than I knew before.


From: ian field on

"Franc Zabkar" <fzabkar(a)iinternode.on.net> wrote in message
news:5csm06tsrugk76gssahbhgomjtqgv8s4be(a)4ax.com...
> On Sat, 5 Jun 2010 20:44:54 +0100, "ian field"
> <gangprobing.alien(a)ntlworld.com> put finger to keyboard and composed:
>
>>Its a transistor assisted ignition, but I don't know whether its points or
>>reluctor.
>
> Contact points would need significant DC current to wet them, ie to
> stop them from becoming oxidised. Magnetic reluctor inputs, OTOH, may
> be AC coupled, ie no DC bias current.

Years ago I built a MOSFET TAC for a small motorcycle, a scrap 19" monitor
donated a 900V/9A MOSFET from its flyback switcher. The TAC used the MOSFET
in grounded gate mode (gate tied to +12V) so the full coil current flowed
through the points but the voltage at contact break never exceeded the
supply voltage, so no arcing and no pitting.

The MOSFET interrupted the coil current very rapidly and eliminated the
energy wasted drawing an arc between the points as they break, the engine
revved easily to valve-bounce in the lowest few gears, by exchanging a bit
of restraint for very impressive revs I could save considerable amounts of
fuel.

The downside is that there doesn't seem to be any such thing as a
logic-level high voltage MOSFET, so there were limitations due to the cold
weather drop in cranking voltage.


From: ian field on

"Dave Plowman (News)" <dave(a)davenoise.co.uk> wrote in message
news:51230b17b1dave(a)davenoise.co.uk...
> In article <idzOn.13964$tY5.13596(a)newsfe17.ams2>,
> ian field <gangprobing.alien(a)ntlworld.com> wrote:
>> As with all components manufactured by Lucas, the God of Darkness,
>> it's purpose is to function for a non-specified length of time and
>> then fail at the most troublesome moment.
>
>> *******
>
>> There was much worse than Lucas about - close running for a photo finish
>> are Wipac, Czeckoslovakian and Italian.
>
> I'm in the UK, and quite the most unreliable 'car' electrics I've ever had
> was on a Bedford van - made by Vauxhall, a GM owned company. With Delco
> electrics. The Delco distributor broke its drive on several occasions.
> Perhaps GM thought a 4 cylinder engine only needed half the effort to
> engineer parts for? The starter and alternator both failed too. All in
> under 50,000 miles.

You might find this an interesting read:


http://www.competition-commission.org.uk/rep_pub/reports/1960_1969/fulltext/025c08.pdf
>
> --
> *Nostalgia isn't what is used to be.
>
> Dave Plowman dave(a)davenoise.co.uk London SW
> To e-mail, change noise into sound.