Hi Vic,
The simplest explanation would be that the diode has (?developed ?) too much series resistance to be able to keep the voltage at its cathode from dropping to zero. My other suspicion was that the storage capacitor in the power supply from which the 18 V come might have lost much of its capacitance such that it is quickly discharged by some load current.
You could check the current drawn through the diode to get an idea whether a 1A type is sufficient.
I wish you much joy using the N4520.
I wish I had one too ...
Regards Kai
Addendum: The "datasheetarchive" has a 1993 Diode Databook, which lists the SR1K-2 diode as a 80V/1A type.
The 1N4007 is a 1000V/1A diode. I guess a 1N4002 (100V/1A) would be sufficient, possibly even a 1N4001 (50V/1A).
The diode just serves as a "one way street", letting current flow out of node A into the solenoid circuit when the 36 V connection is switched off, but blocking any current flowing from the activated 36 V into node A.
The simplest explanation would be that the diode has (?developed ?) too much series resistance to be able to keep the voltage at its cathode from dropping to zero. My other suspicion was that the storage capacitor in the power supply from which the 18 V come might have lost much of its capacitance such that it is quickly discharged by some load current.
You could check the current drawn through the diode to get an idea whether a 1A type is sufficient.
I wish you much joy using the N4520.
I wish I had one too ...
Regards Kai
Addendum: The "datasheetarchive" has a 1993 Diode Databook, which lists the SR1K-2 diode as a 80V/1A type.
The 1N4007 is a 1000V/1A diode. I guess a 1N4002 (100V/1A) would be sufficient, possibly even a 1N4001 (50V/1A).
The diode just serves as a "one way street", letting current flow out of node A into the solenoid circuit when the 36 V connection is switched off, but blocking any current flowing from the activated 36 V into node A.
