Hi All
Im totally new to electronics, and require some help in trying to setup a 0-5V voltage meter using the LM3914 IC (datasheet). The meter will be powered by, and monitor the same rechargeable battery pack (4 x 1.2V @2000mAh). I have read Electronics for Dummies and can still remember the common formulae for electricity from high school i.e V=IR, P=IV, resistors in parrallel.
I have managed to find a Simple Voltage Monitor sheet from NS (http://www.national.com/ms/LB/LB-48.pdf) with the exact specification I need, but I really would like to know how to calculate the resistors that are required for this project.
Im also confused over what pins 4-8 actually mean, but from I could piece together from various implementations of this project on the internet:
I appreciate any help thats provided, and I apologise if I've left any information out of the post.
Im totally new to electronics, and require some help in trying to setup a 0-5V voltage meter using the LM3914 IC (datasheet). The meter will be powered by, and monitor the same rechargeable battery pack (4 x 1.2V @2000mAh). I have read Electronics for Dummies and can still remember the common formulae for electricity from high school i.e V=IR, P=IV, resistors in parrallel.
I have managed to find a Simple Voltage Monitor sheet from NS (http://www.national.com/ms/LB/LB-48.pdf) with the exact specification I need, but I really would like to know how to calculate the resistors that are required for this project.
Im also confused over what pins 4-8 actually mean, but from I could piece together from various implementations of this project on the internet:
- Pin 4 - Vrlo - Lower range of the voltage to be monitored (0.9V x 4 = 3.6V) 0.9V is the voltage at which each battery would be considered as depleted.
- Pin 5 - Signal source
- Pin 6 - Vrhi - High range of voltage to be monitored ( 1.425V x 4 = 5.75V) 1.425V voltage at which each battery is at max charge.
- Pin 7 - Ref Out Vrhi - Vrlo = 2.1V, the voltage range to be monitored i.e. 0.21V per/LED.
- Pin 8 - ?
I appreciate any help thats provided, and I apologise if I've left any information out of the post.
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