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Conversion to an Electronic Voltage



Modern - Reliable - Efficient


The Best Way to Go!!!


An electronic regulator is by far, the best way to control your existing or newly converted 2 brush dynamo. Send us your old CVC and we'll build a nice new modern solid state electronic reg into it for you (with an extra heat sink if neccesary) so externally it looks exactly the same as it did but now uses efficient and reliable modern technology. 

When your vehicle was new its electrical load was slightly lower than the current its dynamo could produce which at the time was fine. In the 1950's a law was introduced that said every motor vehicle must display 2 rear lights. Older vehicles had to be fitted with a second rear light. This put an extra load on the dynamo pushing it to its maximum in most cases. Drivers also wanted brighter lights so the changed headlamp bulbs for higher wattage types. As the years went by the mechanical cut out and/or regulator wear and lose efficiency. Contacts get dirty and start to burn and pit so becoming resistant to electricity. Now the dynamo can't produce the amount of power that the inefficient electrical system is using so the ammeter starts to show a discharge when ever the lights/wipers are used.

Turn the clock forward 50 years or so to the 21st century. These cars are now our pride and joys. 21st century motorists want better lights and better charging than ever before. They try to press ageing components into active service again. The first thing to fail is the regulator. Sometimes this can also cause the dynamo to fail so they have both components rebuilt by a specialist to make them as good as they were when new.

At CDRC we rebuild and/or convert properly to make a very efficient set up that is much better than standard new components. We turn your dynamo and regulator or cut out into 2 components that are up to the demands imposed upon them. In conjunction with high efficiency modern quartz halogen and LED bulbs, driving or riding during the day or night becomes a worry free pleasure.

Our service covers every type of cutout and CVC ever made. The more common units are the faithful old MCR1 & 2, the RF95, the RB106 and even the last of Lucas's regulators, the RB340 current until around 1973. All these units will be greatly improved by the fitting of an electronic regulator. Externally they will look exactly the same so to those where original looks are important (like myself!) nothing is changed apart from what you've always complained about.

The dim lights and bad charging will be a thing of the past with an electronic device.

Electronic reg's are available in different sizes (ratings) just as mechanical reg's were, to suit every vehicle 6 volt and 12 volt, from a basic 8 amp unit to an 11 amp and through a 16 amp unit up to a heavy duty 22 amp unit.

For example, the MCR1/MCR2 CVC (or Miller equiv.) fitted as standard to many British bikes from the late 30's to around 1956. An electronic reg to replace this is available in 6 volt or 12 volt
form, positive + or negative - earth and it can handle up to 100w (at 12v)

Stick with 6 volts if you like or use the same unit for 12 volts should you decide at a later date to upgrade.

The good old Lucas RF95 and the RB106 as fitted to many cars 1946 until the mid 1960's in both 6 & 12 volt form. An electronic regulator is available as a 6 or a 12 volt unit to fit inside the old casing. It's available as a negative earth or positive earth unit which with 12 volts enables you to fit a cigar lighter plug to charge a mobile phone or to fit a more modern radio cassette player or even run your Mp3 or such like. Even without these benefits, lighting and battery charging will be greatly improved.

The last of the line Lucas RB340 regulator (early 1960's until around 1973) was probably the best of them all as far as efficiency is concerned but it is still a mechanical unit prone to failure when it wears and still supps valuable current.
This reg was normally used in conjunction with the ultra reliable Lucas C40 type of dynamo, the type found on Austin, Morris, BMC, Ford cars etc, Cambridge's, Oxfords, Minor, 1100 and 1300 BMC's, Ford Anglia 105E, Cortina Mk1, 2 and 3, Capri, MK1 Escort etc etc. Many people fit a later alternator to these cars unaware of the fact that with an electronic regulator they could keep everything looking original and still have efficient lighting and charging AND be able to wire in accessories such as fog lamps WITHOUT overloading the system and seeing that battery warning light glow. It's cheaper too! Very Happy

Your original battery warning light is kept with all conversions. 

You'll notice a difference though. It's only on when the ignition is on and engine is stopped. No more flickering warning lights. With the engine running at any speed above tickover it'll always be out, showing that the dynamo and not the battery is running the lights etc . I've seen the battery light glow on my BSA 3 wheeler when I hand retard the ignition to get a really slow tickover. Its dynamo is driven direct from the crankshaft at engine speed. You may find the same with an electronic regulator if your dynamo is directly driven, geared to engine speed or you have a slow tickover. At all other times the light is off and raising the rev's to a fast tickover with the lights on shows zero on the ammeter i.e. the dynamo is running everything, not the battery. Perfect compensation. The battery is kept topped up at all times. After starting, a charge is shown on the ammeter as the dynamo replaces the current used for the starter. This gradually drops to zero or very small charge as the battery is charged. No excess charging off the battery, no overcharging, no undercharging and certainly no boiling of the battery. This makes for longer battery life too.

We can retro fit an electronic regulator to replace the original workings of your RB340, again it fits inside the original casing so is hidden.

Rated up to 22 amps and is positive or negative earth.

To sum it up, any vehicle with (or converted to) a 2 brush dynamo will benefit from an electronic regulator conversion.

Any vehicle or watercraft fitted with a Dynastart will benefit from one of our new contollers.

 The resistance of the dynamo's field coil circuit should be not less than 2.5 ohms for a 6 volt system or 5 ohms for a 12 volt system.

To measure this is easy:- Disconnect the D and F wires from your dynamo. Using a standard multimeter test meter set to 200 ohms on its resistance setting (short the probes together first and note the reading - around 0.2 ohms), touch one probe on the F (smaller) terminal and the other probe onto the dynamo's body, making sure you get a good connection if its painted. Now deduct the figure you got by shorting the probes together. 

Some dynamos will read below these figures but can sometimes be brought up to an acceptable value with a modification and without the need to rewind the field coils.

To do a basic test to establish that your dynamo is working :-

Lucas units

Disconnect the D & F (or F2) wires from it. Make a link wire up to connect the 2 terminals together. Between this common connection and the body of the dynamo connect a bulb (for a 6v dynamo use a 6v 21w bulb and for a 12v dynamo use a 12v 21 or 36w bulb). Start the engine and the bulb should light if the dynamo is good. Raise the revs and the bulb should burn brightly and may even blow. Don't do this for too long as the dynamo is running unregulated. 

Bosch and other Continental dynamos/Dynastarters

Disconnect the wires D+ and DF. Connect the DF terminal to earth (DE). Connect a 36w bulb across D+ and earth (DE) and run the engine. If the dynamo is good the bulb will light. Raise the revs and the bulb should burn brightly and may even blow. Don't do this for too long as the dynamo is running unregulated. 

To finish, if your dynamo is working well then your next move ought to be an electronic regulator.

The electronic regulators that I supply are

British designed and British made units.

Each unit when supplied and fitted by myself is fitted with a fuse to protect it along with the dynamo field and armature in the event of a fault occuring.

They are of a robust, very reliable design, using latest electronic components assembled with ‘surface mount’ technology.

Housed in an aluminium alloy case which gives a compact size, electrical ruggedness and high fault tolerance, superior heat transfer to keep the circuitry cool and enhance reliability.

Protection features

Each unit is protected against voltage spikes from the dynamo or on the battery line. Unlike others, i
t will survive short circuiting of the output.

Each unit is
guaranteed against manufacturing defects when fitted as intended by an electrically competent person.

The units are guaranteed for the use that they are intended.

They are NOT guaranteed if mis-used or wrongly connected to

 your vehicle!


Remember- When connecting 4 wires to 4 terminals there are

 23 ways to do it wrong 


Only ONE way to do it right!!!

Each unit I supply is bench tested and comes with foolproof fitting instructions and a wiring diagram. Normally installation just involves polarizing the dynamo, connecting 4 wires and fixing the unit down. It is advised that any wires are marked accordingly before removing the old unit so that re-fitting it or a new unit becomes fool proof. Take your time and you'll do it right.

Your vehicle can retain its original summer/winter charge/light switch (if fitted) although the charge section will now be for show only.

I can supply/fit an electronic regulator for most 6 & 12v automotive applications with dynamo charging inc. watercraft and stand-by generators

AC  AJS  Ariel  Allard Armstrong  Siddeley Alvis  Austin  Bedford  BSA  Buick  Citroen  Crossley  Daimler  Excelsior  Fiat  Ford  Frazer Nash  Hillman  Hotchkiss  Humber  Invicta  Jaguar  James  Jowett  Levis  Lanchester  Lea Francis  Lister  Matchless  MG  Morgan  Morris  MZ  New Hudson  Norton  OEC  OK Supreme  Opel  P&M  Petter  Raleigh  Renault  Riley  Rover  Royal Enfield  Rudge Scott  Singer  Standard  Sunbeam  Talbot  Triumph  Trojan  Vauxhall  Velocette  Vincent  Wolseley 


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