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DavyJones
- 21st July 2009, 03:35
Hi all... I'm not sure what is causing the brownout on my pic but it is most likely a design flaw of my circuit. I'll start by: The brownout is tripped when the pic senses a voltage drop that could affect it correct? I am using 2 pins on the pic to trip these 2 reed relays (http://www.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMv4tz1TW%2fArE1fnnV p%2fQLx%252bxV4mbRVY6hY%3d), I have the relays going to +5vdc on one side and to the porta.2 and porta.5. I do not have any pull up resistors or anything else wired into the relays. When I want to trip the relays I set the appropriate port to 0, porta.2=0 when I am ready to shut the relay off I set porta.2=1 every once in a while when I shut the relays off the device just reboots. I am guessing this is the brownout event taking place. I realize I am not laying out my entire circuit here but I thought I would start with this just to see if anyone has any suggestions on what I might check or look for to try and troubleshoot this. If anyone has any ideas on what to check or suggestions I would appreciate it.
Thanks
David
mackrackit
- 21st July 2009, 04:58
Flyback diode on the relays may help.
DavyJones
- 21st July 2009, 15:06
Flyback diode on the relays may help.

Mack, Thanks I will give that a try. That would just be a simple Schottky diode across the load of the realy right?

Thanks
David
mackrackit
- 21st July 2009, 19:26
Any type is better than none.
http://en.wikipedia.org/wiki/Flyback_diode
DavyJones
- 22nd July 2009, 01:58
[QUOTE=mackrackit;76156]Any type is better than none.
http://en.wikipedia.org/wiki/Flyback_diode[/QUOTE

So far so good... It has not rebooted itself since I added the flyback diodes to the circuit.

I'm very appreciative of the people in this forum you're always a great help.

David
mackrackit
- 22nd July 2009, 03:16
Cool! That makes my day :)