| Electronics > Projects, Designs, and Technical Stuff |
| Active voltage divider? |
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| hlavac:
I have a battery powered circuit that requires several reference voltage levels. Normally one would use a simple voltage divider, but I don't want to piss away any current once the reference level is reached. One way I came up with is make the voltage divider really high resistance, and then add BJT emitter follower to charge the referene cap to voltage Vbe smaller than the divider. Any better ideas? |
| schmitt trigger:
You would definitively require a follower, but instead of using a BJT with its inaccurate Vbe, I would use a micropower opamp as a buffer. |
| spec:
Hi hlavac We would need a lot more information on what you are doing. For example what are the various voltage references and what are they used for. How much current are the the voltage references required to supply. There are a host of micro power techniques and chips but, we will not be able to advise you about them unless we have a complete description, with schematic, of your objectives. |
| StillTrying:
Switch the divider off when it's not needed ? |
| hlavac:
I'm thinking about making a battery powered version of my old logic probe I want to get rid of the big voltage divider (R6-R9). Want to have low enough power consumption to not need any power switch. |
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