I need to clip a 10 volt supply to just over 5 volts to minimize any transient voltage being injected to other channels on a analog input module.

Describe for me the use of a zener diode clipping circuit to miinimizt this voltage? What are the resistor values that should be used? How should the circuit be layed out?

Please help!!!

Thanks.
Tom Huber

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Thanks.

Tom Huber

 

Tom,
Your enquiry is a bit vague. I assume you want to provide a 5 Volt supply from a 10 Volt one. Is this correct? If so, then the resistor value depends upon the current that will be drawn from the 5 Volt side.

If you post a circuit it will make it easier for us to help.

Len

 

Len,

Your assumption is correct. I just want to limit the voltage to 5 VDC. The Supply voltage can go as high as 10 VDC. Current requirements are minimal. I'm in need of just monitoring the voltage after its clipped. The monitoring device has a specification of 7.5 VDC maximum. I'm concerned that there could be some adverse effect on other channels that exist on this monitoring devices, should the voltage be allowed to repeatably go above 7.5 VDC.

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Thanks.

Tom Huber

 

Tom, easiest way is to use a 7805 5v regulator. 3 pins- in, out and ground and it doesn't waste power like a zener does ( important in battery powered applications)

 

I recommend that you use a 6.8 volt zener because it has a sharper "knee" and will not draw current below the zener voltage as the 1N751A could. The series resistor is not critical, since you are not drawing any current. 10K would probably be a good choice.

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I agree.

Len