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BrianG · 02:24 PM

Wow, that does suck! Yeah, some type of circuit would be nice. But, shunting devices are designed to handle very brief pulses of voltage, not steady-state overvoltage. Doing that would just make them blow after a sec or two, and then you'd have full V output again.

I would probably opt for a voltage controlled switch instead. Maybe use an op-amp (typical LM-741) set up in comparator mode. The - input would go to the BEC v output, and the + input would go to a resistor/zener (~8v) divider, also tied to the BEC output line. The op-amp output would feed a PNP transistor in switch mode that is always on provided the BEC output V is lower than the zener v. If the v on the - input exceeds the zener v, the output goes low switching off the transistor. Since the transistor is operating in switch mode (full saturation or off), there should be VERY little heat/power loss. I haven't worked out the details, but such a small simple circuit should be able to be easily added in-line between the BEC and your load.

EDIT: Moved thread to the CC section. Maybe the right people will see this thread...

	(#2)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	05.30.2008, 02:19 PM Wow, that does suck! Yeah, some type of circuit would be nice. But, shunting devices are designed to handle very brief pulses of voltage, not steady-state overvoltage. Doing that would just make them blow after a sec or two, and then you'd have full V output again. I would probably opt for a voltage controlled switch instead. Maybe use an op-amp (typical LM-741) set up in comparator mode. The - input would go to the BEC v output, and the + input would go to a resistor/zener (~8v) divider, also tied to the BEC output line. The op-amp output would feed a PNP transistor in switch mode that is always on provided the BEC output V is lower than the zener v. If the v on the - input exceeds the zener v, the output goes low switching off the transistor. Since the transistor is operating in switch mode (full saturation or off), there should be VERY little heat/power loss. I haven't worked out the details, but such a small simple circuit should be able to be easily added in-line between the BEC and your load. EDIT: Moved thread to the CC section. Maybe the right people will see this thread... Last edited by BrianG; 05.30.2008 at 02:24 PM.