Lotus Elan

Electronic regulator with a dynamo

PostPost by: pereirac » Wed Aug 29, 2018 8:17 am

Just wondered if anybody still using a dynamo had replaced the electro mechanical Lucas control box with an electronic regulator and if it was worth doing? I realise the easiest option is to fit an alternator but for some illogical reason I quite like my heavy old dynamo :D


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87 Excel SE
97 Alpina B10

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PostPost by: gherlt » Wed Aug 29, 2018 11:21 am

you might take a look at the Dynamators (et al), alternators with dynamo looks.
And then the old regulator RBxxx can be replaced by a dummy one or rewired, as it is not needed anymore.
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PostPost by: Andy8421 » Wed Aug 29, 2018 10:38 pm

I built a homebrew electronic control for a standard dynamo. I based it upon an aftermarket design for a classic British bike (can't remember which) that used 'pulse width modulation' to drive the field coil and control dynamo output voltage. I will see if I can dig out the link.

The Lucas control box does a couple of things, it disconnects the dynamo when its output voltage falls below the battery voltage, and it has a go at controlling the charge rate. I kept the electro-mechanical disconnect as I didn't want to introduce the additional voltage drop of a diode. I was racing the car and it was important to keep the original dynamo in order to be eligible, but I had a racing battery and the output voltage of the dynamo was all over the place. I built the regulator to give me a stable output voltage.

edit: while searching for the original circuit design I came across this: http://cloversystems.com/wp-content/upl ... rature.pdf

I don't know anything about the firm, but the product seems to be what you are after.
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