06-04-2021, 09:51 AM
Although a radio tech in a past life I am all for avoiding electronics. The absence of is much of the attraction of old cars. I dont know exactly how the various electronic regulators work applied to Sevens and two brush.
Some electromechanical regulators switch the field wire to output (lucas) and some to earth (Ford). Dunno about Ducellier but has to be the former. If the internal resistor is still intact the action of the regualtor would be to reduce to not less than summer rate. If the reistor is defucnct with the 3rd brush insulated from comm there would be open circuit between F terminal and D terminal and F and earth, all external wires disconnected.
I have no experience of using an em regulator in conjunction with 3rd brush but can see no reason why not. Normally regulators are matched to the dynamo and prevent excessive output but the minimum will exceed safe output for a Seven. Hence some means necessary to limit max output; ie the 3rd brush. Hopefully the rapid switching action would not affect the brush.
If retaining standard manual control and the summer fuction is working by an extrnal instead of original internal resistor, can add a 3rd positon of no charge by switching the F lead to off. (Do not attempt to switch the Dyn output lead off)
Efficiency is really only a consideration at full charge and of interest with Sevens as no surplus output to dissipate in rsistors. At part charge there is surplus and a wee bit is absorbed by the summer resitor.
All working Seven dyns are precious esp if a thick comm remaining so take care not to damage.
Some electromechanical regulators switch the field wire to output (lucas) and some to earth (Ford). Dunno about Ducellier but has to be the former. If the internal resistor is still intact the action of the regualtor would be to reduce to not less than summer rate. If the reistor is defucnct with the 3rd brush insulated from comm there would be open circuit between F terminal and D terminal and F and earth, all external wires disconnected.
I have no experience of using an em regulator in conjunction with 3rd brush but can see no reason why not. Normally regulators are matched to the dynamo and prevent excessive output but the minimum will exceed safe output for a Seven. Hence some means necessary to limit max output; ie the 3rd brush. Hopefully the rapid switching action would not affect the brush.
If retaining standard manual control and the summer fuction is working by an extrnal instead of original internal resistor, can add a 3rd positon of no charge by switching the F lead to off. (Do not attempt to switch the Dyn output lead off)
Efficiency is really only a consideration at full charge and of interest with Sevens as no surplus output to dissipate in rsistors. At part charge there is surplus and a wee bit is absorbed by the summer resitor.
All working Seven dyns are precious esp if a thick comm remaining so take care not to damage.