Hi Bob,
Better check out the theory & trace out the paths first. The full wave
bridge is a common way to make a DC device non polarity sensitive.
Steering diodes would be another description.
Dave Russell
Bob Spidell wrote:
> re:
>
> "If a full wave bridge rectifier were connected between the supply
> connections & the permanent magnet motor, the supply polarity could
> be connected to the motor either way & it would still run in the same
> direction"
>
>
> Don't think so. Rectifiers (diodes, usually arranged as half- or
> full-wave bridges) are used to convert AC current into a "lumpy" DC
> current, which is usually smoothed with capacitors. A full-wave
> bridge rectifier on a DC current (Healey "power supply") would just
> pass the current (to only one of its outputs).
>
>
> bs
>> Hi Earl,
>>
>> Most older DC blower motors were built with series connected
>> armature & field windings. They will rotate in the same direction
>> regardless of which way the power is connected. These motors "can"
>> be reversed by INTERNALLY reversing the connections of the field or
>> of the armature but not both.
>>
>> Some newer motors have permanent magnets in place of the field
>> windings. This type of motor will run backward if the supply
>> connections are reversed.
>>
>> If a full wave bridge rectifier were connected between the supply
>> connections & the permanent magnet motor, the supply polarity
>> could be connected to the motor either way & it would still run in
>> the same direction - As Jim H. says.
>>
>> To my knowledge, all Healey blower motors were of the first type.
>> Not to say that the "reversing motor" in question has not been
>> changed to a permanent magnet type somewhere along the way. Either
>> that or your theory about blockage may be correct.
>>
>> Certainly an interesting thread.
>>
>> Dave Russell
|