[Healeys] Solid-state voltage regulators

Alex alexmm at roadrunner.com
Wed Jul 9 09:24:09 MDT 2014


It is with some interest that I've been following this thread, as the folks
on the MG-T reflector have similar wishes.

Being an "electroniker" (for about 55 years; you can see some of my Web
projects here: http://home.roadrunner.com/~alexmm/  ) one of my MG friends
asked about an electronic control box (voltage regulator). He knew the folks
in New Hampshire that knew the Jeffers family.  With his connection I
visited an automobile restoration shop in NH and they kindly gave me a
Jeffers voltage regulator for an MG-T car that is supposedly defunct, but
intact.

Inspecting it, I was not impressed. For starters, the Jeffers Wilton box
uses edge-wipe sockets to hold the two integrated circuits (ICs) in the
regulator. Edge-wipe IC sockets are low reliability interconnects. In my
radio service business, and in my hobby work, I never use them. I have seen
them exhibit failures due to moisture and oxidation, even in benign
non-automotive applications.

For my money, I only use screw-machined IC sockets. These make what is
called a gas-tight seal between the lead frames (pins) of the IC package,
and the socket. Screw-machined sockets are the only types I would use to
hold ICs in a circuit board that would be subject to shock, vibration, and
extremes of temperature, which is what you have under the bonnet of our
cars. They are more expensive than the cheap edge-wipe sockets, but they are
utterly reliable in this application where there is a separable
interconnect.

The Jeffers voltage regulator also uses a pair of 8-pin "miniDIP" ICs that
are unmarked. He apparently ground off the nomenclature in order to preserve
his proprietary design. I suspect they are op-amps or comparators, and I
have thought about reverse engineering the board to generate a schematic,
but haven't been motivated to do that yet.

The shop I received the regulator from did contact the Jeffers family about
a month ago to determine if his notes and/or components might be available,
but I was told the family is still in mourning and didn't wish to pursue
this at this time. I may try again in a few months.

In the meantime, as you can see, there are outfits that make these voltage
regulators, and there is also a goodly amount of info on the Web about how
to roll your own. Some of the designs avoid using ICs, and use only discrete
semiconductors. These designs seem simpler to me.

In addition to the reference cited in this reflector, there is info on the
Web about how to use a 30019 Bosch regulator as an RB106 substitute.

== Alex in Maine
     "The Blue Mainie," 1960 Austin Healey 3000 BT7
     "Conkling," 1946 M.G. TC #1321
     Former owner 1957 A-H 100-6, 1967 A-H BJ8,
     1965 MG Midget
     http://home.roadrunner.com/~alexmm


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