This is the second dynamo that might be installed on my engine. I am using electronic ignition which requires 8 amps, fuel injection which requires 10 amps, and fuel transfer pumps that require two amps. This totals 18 amps for the engine bus powered by dynamo number two leaving a couple of amps for battery charging after startup. Dynamo number one is also a 20 amp unit contained in the Dhiel accy case. It powers the avionics bus and the main bus which has a total load of 18 amps.
Note: The information for dynamo 2 was provided by Mark Langford and modified to meet my installation requirements. Thanks Mark for the research.
Dynamo 2 is from a John Deere model 670 lawn tractor (any X70, actually), and weighs 4 pounds with the regulator. Output is 20 amps minimum when driven by the mower's 6" pulley running at 2500 rpm. N52BL's engine has a max rpm of 3600 compared to 3000 for the John Deere engine so the engine pully will be sized with a 5" diameter to maintain the same maximum dynamo rpm.
John Deere part numbers are AM877557 for the alternator ($160), and AM101406 for the regulator ($67). A dynamo uses permanent magnets rather than field excited electromagnets, so it doesn't "need" electricity for the windings to produce electricity. The diagram below shows the standard John Deere voltage regulator. N52BL uses the GPASC three pole regulator that has two AC inputs and one DC output terminal. Otherwise operation is exactly the same as the stock John Deere installation.
Here's how you hook it up...
...and a detailed drawing never hurts.
