A Low cost electronic dynamo regulator

A month or two ago a customer sent me a regulator to test. I thought he meant it was a DVR2, but was in fact of the type available cheaply from a good number of sources. This was a 6V Positive Earth unit in a neat cast alloy case, of Chinese origin, but unbranded.

Well I tested it and reported to the customer that it had indeed expired. He said for me to keep it and do what I will with it. So what would any design engineer do? Well I started to open it up and remove the hard black potting compound, little by little. It quickly became apparent that the device was simple in the extreme. The pieced together circuit diagram is shown here, more or less:

circuit diagram of a cheap and nasty dynamo regulator
quick ‘n dirty regulator circuit

To my eye this circuit looks like the sort of thing an inexperienced designer might sketch out as a first stab. Incredibly vague reference setting and low gain suggest poor voltage regulation and wide tolerance variation unit to unit (and against speed, load and temperature variations). SPICE simulation indeed confirms the predictable poor performance. That is to say nothing of fault resilience and reliability. So how does such a design get brought to market? How could meaningful testing have been carried out?

To sum up, buyer beware! Lowest cost and best quality are not often compatible. Buy cheap, buy twice is a more likely outcome (the 2nd purchase being a DVR2 perhaps?). Comments welcome . . .

Electro Dynamic Solutions Ltd

The dust has by now well and truly settled following transfer of the DVR3 & DVR4 regulator products to Electro Dynamic Solutions Ltd. Peter, the company Director, will be able to help with everything related to these well established products. Wishing EDS a successful future in supplying the best Voltage Regulators for Classic Cars and other vehicles equipped with Dynamos (or DC generators).

For Dynamo Regulators it is satisfying that we are once more able to concentrate on the sales and support of our very successful DVR2 regulators. Helping to provide reliable charging to classic motorcycles around the world.

DVR3 & DVR4 regulator products

On February 12th 2019 I wrote on dynamoregulators.com:

“I aim to streamline our business and focus on our DVR2 regulators (primarily aimed at motorcycle use). Therefore I am seeking to exclusively licence our popular DVR3 & DVR4 products to a Professional Business; one with the appropriate technical and commercial skills and ambition. If interested please contact me for a confidential chat.”

We have sound reasons for wishing to concentrate on the DVR2 as our main product line. Not least is that this move will free up some time for other activities. The change would have to come at some point with advancing years, and my recent illness has helped to prompt a rethink of the work-life balance thing. And a change is as good as a rest, so it is said.

Our DVR3 & 4 were established about 10 years ago following the success of the DVR2. They proved to be popular and sales grew ‘organically’, almost exclusively by word of mouth. These regulators provide a robust and precise electronic regulator solution for older vehicles. They are probably most cost effective product of their ilk in the classic marketplace. We have already received comments saying “it’s a shame you are ceasing to sell such a good product”, or “will you rethink your decision?” However we really hope these regulators will remain available, albeit via another outlet.

We are now seeking a company to take on these products so sales can continue into the future. Ideally we envisage licencing the products so they can be manufactured and marketed independently of Dynamo Regulators Ltd. Our interest would be maintained by a modest royalty on items sold. So the new company would need some electronic product design & manufacturing expertise, suitable marketing and sales skills, and familiarity with dynamo charging systems on classic vehicles. The current income from the DVR3 & 4 product lines is some tens of thousand of pounds per annum. With some advertising and creating a higher profile this turnover could be increased to a 6 figure sum with confidence.

So if you are interested in the potential for this new business venture please contact Mike Hutchings on 01489 880552 or mjh@dynamoregulators.com for a preliminary discussion of the possibilities.

Well, this is embarrassing

This week we sent out our last DVR2-N regulator, until new stocks arrive (expected early June). We really hate to disappoint would be customers, and being out of stock is obviously bad business. The Negative Earth DVR2 is one of our best selling products, in fact this past few months we have sold more Negative than Positive DVR2’s.

Predicting changing demand for products is something we always try to allow for. But this principal reason for the current shortage stems from unavailable parts . A key part we use in the design became unavailable with a lead time of many months until the manufacturer would process a new batch. So we asked our PCB assembly people to use an alternative part with similar or better specifications, at least on paper. Being cautious sorts by nature we would first prove the design with the substitute part, before production re-commenced. Just as well we did as the new part proved to insufficiently robust against all the test scenarios we challenge our designs to.

So we had an unscheduled back to the drawing board moment, involving new device search and evaluation phases. This time around testing proved entirely successfully. Production was recommenced and the first full batch of the revised units is due shortly, in early June.

Once again, we are very sorry for the inconvenience caused at this busy time of year for classic events.


Delayed in Post

We have consistently found the Royal Mail postal service to offer a convenient, reasonably priced and reliable service, and suited to the delivery requirements of DRL. There have been occasions when packages to our non-UK customers have been delayed, but really these are few and far between.

However a package sent to Dubai has become our new benchmark of postal inefficiency.

A dynamo regulator sent out in early January apparently reached Dubai within a couple of weeks, but the UAR postal service had failed to see it passed on to the customer. It was returned to the UK in late February. From time to time I rechecked the tracking details, but the packet seemed to have become stuck in the returns center. Meanwhile a new item was sent out to the UK address of a party who would forward it to our customer in due course.

I never got around to filling in the RM claim form and had really forgotten this loss of a mail item. Until last Saturday, 19 May, when postman delivered it returned to sender. Some 22 weeks in all had elapsed since posting. Hope never to see this performance eclipsed!

Seasons Greetings to all

Wishing all our customers a very Merry Christmas & Happy New Year.blue Christmas tree

And many thanks to all our DVR Regulator purchasers for making this our best year yet. Sales have been up for each and every month of 2017 compared with last year. We look forward to continuing to supply the broadest range of solid state dynamo regulators to meet the requirements of cherished vehicle owners into the New Year and beyond.

Our Postage Rates

For some reason of late (or mayhaps for no good reason) a high proportion of our valued non UK customers, ordering via our website, are failing to select the correct regulator price including post from the drop down boxes. Come on lads, play fair.

We only charge a modest amount for postage, which is as it should be. But it can’t be right that our UK purchasers are subsidising the postage cost to those buying from farther afield. Non-UK purchasers please select  ‘European’ or ‘Rest of World’ post inclusive price from the drop-down box on product pages, it’s as easy as that. Thank you.

DVR Regulator Suppliers

On occasion we are asked whether we supply resellers with our regulators. And the answer is ‘yes we do’. For example we supply to Eugene ‘Skip’ Brolund in the USA, Pazon Ignitions of New Zealand, Eurobrit MC’s of Australia, Brightspark Magnetos over in France, and SRM Engineering and CD&RC* in the UK. However in the main we sell direct to end customers via our efficient website, including exporting to many countries (low postal rates).

DVR3 regulator
DRL’s DVR3N dynamo regulator

 * It appears that CDRC Ltd now use a regulator circuit design which was originated in the USA  in the majority of their units (ref http://www.classicregulator.com/about-us/ ). Until around last year they primarily used our DVR3 & 4 regulators. These are easily recognised by the top quality distinctive CNC machined aluminium cases we employ.


Welcome to the new Dynamo Regulators Ltd WordPress site.

A place intended for additional information and discussion regarding the world’s most complete range of solid state dynamo regulators. So watch this space!

Our main website is still to be found at www.dynamoregulators.com