15-07-2020, 09:15 AM
Steve Marks at Magnetoguys sent me this which I thought would be good to post here just as another debating point:
"The Conrad Direct device is a very standard bridge rectifier which contains four rectifier diodes. If wired up the way it is suggested, there will be two rectifier diodes in parallel between the dynamo and battery. Nowadays, rectifier diodes are a poor choice for this application - too much volts drop for one thing. When Schottky diodes came along, they were a better choice. Time (and technology) moves on and neither of these options are as good as our Smart Diode Cut Out (but I guess I would say that wouldn't I! ?) but don't take my word for it - compare the performance figures for it listed on the website compared to the figures for Rectifier and Schottky diodes! No doubt the time will come when the Smart Diode becomes obsolete because something better has been developed.
It is interesting to see that many still look on electronics with suspicion and are convinced that they will fail. Nothing is perfect but modern electronics is much more reliable than early mechanical or electromechanical options - and they don't require maintenance and adjustment either! Personally, for me it's a no-brainer. Vehicles I have which originally had three brush dynamos have all been converted to two brush operation and use an electronic regulator. The AO and DVR ones are good. The only time we fit our Smart Diode Cut Out is if the owner wants to keep things as original as possible or if the dynamo in question has the field provided by permanent magnet(s) in which case there is no way to regulate the output by adjusting the field strength so an electronic regulator is not suitable."
It is interesting, as it still puts the onus on carrying a spare being the crucial thing for roadside fixers. The cheapest AO device (now not really recommended by AO for car use), is about 50 quid which is just about in range for doing that - not a lot more than what people are doing with electronic points systems.
...
Zeto - the reason I started looked at this again was as the Speedex has a need for a water pump and also has no original PLC switch or cutout. Ian had suggested that the Davies Craig pumps would still work 'out of range' on 6V, but I'd started to look at 12V and all the options just because it's a non-original car. I still want to aim for simplicity (in the longer term beyond running an auxiliary battery and a cheap 12V-only aux pump) and being able to be in control/fix things!
"The Conrad Direct device is a very standard bridge rectifier which contains four rectifier diodes. If wired up the way it is suggested, there will be two rectifier diodes in parallel between the dynamo and battery. Nowadays, rectifier diodes are a poor choice for this application - too much volts drop for one thing. When Schottky diodes came along, they were a better choice. Time (and technology) moves on and neither of these options are as good as our Smart Diode Cut Out (but I guess I would say that wouldn't I! ?) but don't take my word for it - compare the performance figures for it listed on the website compared to the figures for Rectifier and Schottky diodes! No doubt the time will come when the Smart Diode becomes obsolete because something better has been developed.
It is interesting to see that many still look on electronics with suspicion and are convinced that they will fail. Nothing is perfect but modern electronics is much more reliable than early mechanical or electromechanical options - and they don't require maintenance and adjustment either! Personally, for me it's a no-brainer. Vehicles I have which originally had three brush dynamos have all been converted to two brush operation and use an electronic regulator. The AO and DVR ones are good. The only time we fit our Smart Diode Cut Out is if the owner wants to keep things as original as possible or if the dynamo in question has the field provided by permanent magnet(s) in which case there is no way to regulate the output by adjusting the field strength so an electronic regulator is not suitable."
It is interesting, as it still puts the onus on carrying a spare being the crucial thing for roadside fixers. The cheapest AO device (now not really recommended by AO for car use), is about 50 quid which is just about in range for doing that - not a lot more than what people are doing with electronic points systems.
...
Zeto - the reason I started looked at this again was as the Speedex has a need for a water pump and also has no original PLC switch or cutout. Ian had suggested that the Davies Craig pumps would still work 'out of range' on 6V, but I'd started to look at 12V and all the options just because it's a non-original car. I still want to aim for simplicity (in the longer term beyond running an auxiliary battery and a cheap 12V-only aux pump) and being able to be in control/fix things!