30-08-2023, 11:45 AM
Hi Harry
The Cathode of the Texas SM74611 chip (Tab and centre Pin 2) connects in place of the A terminal of the cutout. This then usually feeds via the Charge/Lighting switch through the Ammeter and then to the Battery positive.
The Anode of the 74611 (Outer Pins 1 and 3, connected together) connects in place of the D terminal of the cutout. This is fed from the main D output of the dynamo.
Current flow when charging is from Anode to Cathode
The average heat dissipation of this device is less than a quarter of a watt, so the package should not need any additional heat sink.
Later cars like the Ruby had a cutout which also incorporated the resistor for the "half charge" circuit. You will have to make separate arrangements if you want the half charge feature.
The Cathode of the Texas SM74611 chip (Tab and centre Pin 2) connects in place of the A terminal of the cutout. This then usually feeds via the Charge/Lighting switch through the Ammeter and then to the Battery positive.
The Anode of the 74611 (Outer Pins 1 and 3, connected together) connects in place of the D terminal of the cutout. This is fed from the main D output of the dynamo.
Current flow when charging is from Anode to Cathode
The average heat dissipation of this device is less than a quarter of a watt, so the package should not need any additional heat sink.
Later cars like the Ruby had a cutout which also incorporated the resistor for the "half charge" circuit. You will have to make separate arrangements if you want the half charge feature.