lm3914 ic based on simple battery tester


Posted on Feb 7, 2014

This circuit employs the popular and easy to find LM3914 IC. This kind of IC is quite very simple to drive, requires no voltage regulators (it features a built in voltage regulator) and can be powered from almost every resource. Once the test switch is pushed, the Car battery voltage is supply into a high impedance voltage divider. His function is


lm3914 ic based on simple battery tester
Click here to download the full size of the above Circuit.

to divide 12V to 1, 25V (or lower values to reduced values). This solution is much better than enabling the internal voltage regulator set the 12V sample voltage to be feed into the internal voltage divider simply because it cannot regulate 12V if the voltage falls lower (linear regulators only step down). Simply wiring with no change, the regulator provides secure 1, 25V which can be fed into the precision internal resistor cascade to create sample voltages to the internal comparators. In any case the default establishing let you to determine voltages between 8 and 12V however you can measure even from 0V to 12V setting the offset trimmer to 0 (but i believe that below 9 volt your vehicle would not start). There is a smoothing capacitor (4700uF 16V) it is used to adsorb EMF noises produced from the ignition coil if you`re testing the battery during the engine working. Diesel engines would not need it, but i am not sure. If you want more a level graph rather than a bar graph simply disconnect pin 9 on the IC (MODE) from power. The calculations are usually simple (default).




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

AttoBasic
650Mhz amplifying prescaler probe
Harmonic Generator
Door Lock Wiring
Keypad Talking To LCD Via AT89S51
Amplifier Timer
AVR ISP ScoketBoard
7812 ic 12 volt 30 amp psu circuit electronic circuit schematic
burglar alarm using ic timer 555556
Condenser Microphone Amplifier Schematic using BEL 1895 IC



Top