Forum Discussion
Wayne_Dohnal
Oct 16, 2014Explorer
Almost everything I know (including pictures) is in this thread:
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/24492263/srt/pa/pging/1/page/1
What I can add is:
(1) The fan is not thermistor controlled. It's controlled by output current sensing. Don't know if that's direct or indirect current sensing.
(2) I suggest using a lower resistance than 47k for the boost trigger. 47k pulls the sense voltage barely to the trigger borderline, and might not trigger boost on some converters.
(3) The reset circuit in the thread is for the level-triggered-reset daughterboards, which I suspect are older, while the newer boards use edge-triggered reset. The edge trigger circuit is to hook a 1k resistor in series with a 1000 pF capacitor. Hook the resistor end to the converter + output, and the capacitor end to pin 4 of the PIC microcontroller. Then hook the reset momentary switch/button from the resistor-to-capacitor connection to the converter's - output. Power cycling the converter also causes a reset.
I thought the fans were variable speed, but it's been a while and my memory reliability is getting worse every day. I've run across only 2 versions of the daughterboard, could be more of course.
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/24492263/srt/pa/pging/1/page/1
What I can add is:
(1) The fan is not thermistor controlled. It's controlled by output current sensing. Don't know if that's direct or indirect current sensing.
(2) I suggest using a lower resistance than 47k for the boost trigger. 47k pulls the sense voltage barely to the trigger borderline, and might not trigger boost on some converters.
(3) The reset circuit in the thread is for the level-triggered-reset daughterboards, which I suspect are older, while the newer boards use edge-triggered reset. The edge trigger circuit is to hook a 1k resistor in series with a 1000 pF capacitor. Hook the resistor end to the converter + output, and the capacitor end to pin 4 of the PIC microcontroller. Then hook the reset momentary switch/button from the resistor-to-capacitor connection to the converter's - output. Power cycling the converter also causes a reset.
I thought the fans were variable speed, but it's been a while and my memory reliability is getting worse every day. I've run across only 2 versions of the daughterboard, could be more of course.
About Technical Issues
Having RV issues? Connect with others who have been in your shoes.24,189 PostsLatest Activity: Jan 21, 2025