Re: The Duchess Project: 1940 Super 8 Convertible Sedan

Posted by HH56 On 2020/3/10 12:44:17

I believe the main reason they didn't want mechanics messing with the adjustment is it needs some special conditions and equipment to measure the current allowed to pass. In just turning the screw without any idea of what is happening it would be so easy to get it way out of range.

I would need to look at the switch closely to see the entire strip but from the photo I think the adjustment screw would need to tighten to increase the current capacity. If it works like later switches the current is fed thru a strip that bends when heated by excess current flow. To increase capacity, tightening the screw would put more pressure against the strip so it would need more current to bend it enough away from the contact point so the connection could be broken.

I don't know how much it takes to change the action hence the need for equipment and a steady current flow while doing the adjustment but I suspect the screw tightening would not be more than a 1/16 to 1/8 turn without getting to the point it might be so far out of adjustment it would take an unsafe amount of overcurrent before anything happened.