Car Battery Monitor 12 Volt

Published:2012/9/25 21:48:00 Author:muriel | Keyword: Car Battery, Monitor, 12 Volt | From:SeekIC

Here is an interesting Car Battery Monitor circuit of a low power electronic dc voltmeter circuit that can be used with car electric systems that run on 12 volt batteries. The voltmeter is an expanded scale type that indicates small voltage steps over the 10 to 16 volt range for 12 volt batteries.At the heart of the circuit is a ubiquitous dot-bar volt meter LM3914N (IC1). This IC is operated in the expanded-scale mode so that the circuit responds in the 10-16V range. IC1 outputs a steady voltage on pin 7 from the internal voltage reference. This is fed via voltage dividers VR2and R2 to the internal reference input pins(4&8) to set the range that the meter is sensitive to. The measured voltage is fed in on pin 5 via the voltage divider consisting of R1 and VR1. This divider scales the input voltage down to a range that is useful to IC1. Car Battery Monitor schematic for 12V batteries It is possible to set the meter to read equal steps across a variety of upper and lower voltages. Different colored LEDs can be used for the voltage level indicators(D1-D10). It will be necessary to have an adjustable regulated DC lab power supply and a good quality digital volt meter (DVM) to perform the calibration. Connect the external volt meter across pins 6 and 4 of IC1 and adjust VR2 for a reading of 1.2 volts. Center the settings of VR1 and VR3. If the span between the end points of VR1 is 4.5V, the circuit is ready to use as a 10.5 to 15V scale battery monitor.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Control_Circuit/Car_Battery_Monitor_12_Volt.html

Print this Page | Comments | Reading(3)