 | | Voltage Sensor
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| Hello fellow Mindstomers, I am seeking some direction in the development of a Voltage Sensor I wish to use with my RCX. I have solar cell connected to a 12Volt (1.3A) sealed lead acid battery via a small trickle charger PCB (bought as a kit). The (...) (22 years ago, 16-Sep-02, to lugnet.robotics)
| | | | | Re: Voltage Sensor
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| Are you powering the RCX from this battery? If so you can use the RCX it'self to monitor the battery. task main() { while (true) { SetUserDisplay(BatteryLevel(), 3); } } I use this to detect if my 1.0 RCX is plugged in or on batterys. Hope that (...) (22 years ago, 16-Sep-02, to lugnet.robotics)
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| Hello, (...) This idea, while in itself interesting, will not work when the 12V battery gets regulated down to 9V. This is because these 9V will barely vary across the regulator's permitted input range. If of course the regulator is specifically (...) (22 years ago, 16-Sep-02, to lugnet.robotics)
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| (...) It's amazing when you get a different perspective on a problem! While not really applicable for this application the idea is indeed very elegant and saves on a precious input port. I have a spare regulator which I will modify to test this out. (...) (22 years ago, 17-Sep-02, to lugnet.robotics)
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| (...) Thanks Dean, I had some thought in monitoring the battery level directly through RCX. But potentially I wanted to monitor multiple battery sources so I thought I might as well as develop an external sensor. Another thought was that the same (...) (22 years ago, 17-Sep-02, to lugnet.robotics)
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| Caution: the your external supply has one side connected to RCX ground, which is itself connected to sensor input connector right side. Whichever circuit you choose, you will have to make sure that sensor connector will not be reversed (the (...) (22 years ago, 17-Sep-02, to lugnet.robotics)
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| Hello Tom, (...) Yes. You need a low impedance output driving 0..5V into the RCX, thus overriding its internal pullup. (...) Actually, I should have written "resolution" instead of "accuracy". The 10..15V range spans 5V with 256 steps, giving you a (...) (22 years ago, 17-Sep-02, to lugnet.robotics)
| | | | | Re: Voltage Sensor
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| Hello again, if you have difficulties making sense out of my previous posting, try viewing it with a fixed-width font. Otherwise all fomulas will ook scrambled. In the Web interface, "view raw message" is likely to work for that purpose, but of (...) (22 years ago, 17-Sep-02, to lugnet.robotics)
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| Tom, it is possible to also buy ready made voltage sensors for the RCX, see (URL) have used a most of the sensors from this company for data-logging purposes, but have not yet used the voltage sensor. If you would like more info, I can probably try (...) (22 years ago, 18-Sep-02, to lugnet.robotics)
| | | | | Re: Voltage Sensor
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| (...) Hello Nathan, At this stage I am wanting to include this sensor as part of a larger suite of components - Voltage regulator and Trickle charger. Ultimately I want to etch all of these circuits onto a single board and tuck it away in a lego (...) (22 years ago, 18-Sep-02, to lugnet.robotics)
| | | | | Re: Voltage Sensor
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| (...) Wow, thanks Horst. Your last email had 'weekend project' written all over it. Everything was quite straight forward (including the equations) and extremely well presented. I'll keep you posted on how it goes, and if I get stuck, no doubt you (...) (22 years ago, 18-Sep-02, to lugnet.robotics)
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