What is the difference between dynamo and alternator

[Sandun]

Can you tell me ,What is the difference between dynamo and alternator ?

[MarkyB]

Alternators give better output at lower revs.
Dynamos are easier to repair and more electronically robust.

[bmcecosse]

Alternator can be run at much higher revs - and so can have a smaller pulley fitted, which allows it to produce power when the engine is idling.. It generates AC current which then needs to be rectified to DC for the car battery. And this is where the unreliabilty sets in -with a generator it is all much more robust. Stick with it!

[lambrettalad]

HI
After five years driving cars with dynamos ,3 failures
45 years of driving cars with alternators ,1 failure and that was back in 1973!

unless you carry spares for a dynamo ,chances of being repaired quickly on a sunday afternoon NIL

[MarkyB]

Spares for a dynamo = 2 brushes, hardly a problem to keep in stock and in the car.
If the battery gets fitted the wrong way round the alternator is toast and probably cheaper to replace than repair.
It is said that any electric welding can have the same effect.
Running the engine with the wires not connected to the alternator is another killer.

[lambrettalad]

if's n but's
thats why you pays your money and you takes your pick

[MarkyB]

It's easy to knacker an alternator, hard to kill a dynamo.
Is that clear enough?

[mike.perry]

Dynamos wear out (eventually), Alternators go wrong (occasionally)

[lambrettalad]

Dynalite-the Alternator replacement for C45 Dynamo -Earth

This might (or something like it) please some of those who like their cars looking original

ADVERT FROM INTERNET

If you are running your classic car with the lights, wipers, heater etc. on it is probable that your Lucas dynamo is struggling to keep the battery properly charged for the next time you want to start the engine. Modern cars overcome this by using an alternator. The Dynalite by Powerlite is such an alternator which will give 80% more power (40 amps) than a dynamo and the remarkable thing is that it LOOKS JUST LIKE YOUR ORIGINAL LUCAS DYNAMO. If yours has C45 stamped on it, this is the Dynalite you need. You will need to use your existing pulley, the input shaft is 17mm diameter and most pulleys should fit. It is supplied with full instructions. NEGATIVE EARTH ONLY

For information on the use of the name Lucas please read our brief history of Lucas and guide to Lucas parts.

Part-no. 081.203
Pack-size: each
Stock: In stock
Avg customer rating: 4 out of 5 (view all 2 ratings)
(what does this mean?)
Price: £354.00 (ex VAT)[frame][/frame][frame][img]

[bmcecosse]

'Heart attack' at the price...........

[MarkyB]

If you are running your classic car with the lights, wipers, heater etc

What nonsense!
Unless you are adding electrical items to the car the original set up is fine as it is.

[ampwhu]

i posted on another thread about this. an alternator is cheaper to replace than a dynamo. i think you can buy NEW for less than £50 delivered. in 25 years, i've never had one fail. thats over half a million miles on the road.

dynamo's were good in 1955, but not today.

[MarkyB]

These are 50s cars, simple and robust.
Modern cars are full of electrics and electronics which a dynamo wouldn't be suitable for.

[Alec]

Hello Ampwhu,

" in 25 years, i've never had one fail. "

You have been very lucky. There is nothing wrong with dynamos and are quite adequate for standard cars.

Alec

[lambrettalad]

It depends on what you want ,what you prefer,what you believe in etc this topic should be a sticky,no point discussing details,when it's based on personal preferences

[Alex'n'Ane]

There is a reason all modern cars have alternators, just saying... Also i'd rather not break down, than break down then probably be able to fix it..
Also if you do lots of shortish journeys, especially at night, then just running a dynamo can leave you with a flat, potentially damaged battery.

[JOWETTJAVELIN]

You can start it on the handle to 'save' the battery as the starter motor draws the most current. You can actually run for very many miles with the charge warning lamp glowing.

[chesney]

Certainly can 50 miles I did, no irregular behaviour either (other than the lamp being on)

[rayofleamington]

There is a reason all modern cars have alternators

Power to weight ratio and the need to supply a LOT of 12v consumers when the engine is at idle.

It's horses for courses, and I've commuted year in year out all year round without 'needing' an alternator. After long periods (months) of stop start commuting in the cold/wet/dark I'd rather do a periodic mains-charge of the 12v battery (minutes of effort) than fit an alternator (not a 5 minute job).

[ampwhu]

if your interested in keeping the car the same as it was 50 years ago, then keep your dynamo.

if your interested in modernising your car (like me), then fit an alternator. with the amount of "add ons" i have, a dynam,o wouldn't even power my sidelights.