MP3Car.com - View Single Post - How could I make a low battery indicator?

ramy_zohair · 12-06-2006, 11:57 PM

Quote: Originally Posted by Wiredwrx

I don't think there is a way to trigger/light an LED when voltage drops (a battery dies because/when the voltage drops below a certain level) to a predetermined or specific level, with out being powered. Perhaps you can just add some sort of button, that when pushed, will light an LED, unless it is below a certain voltage. You can do this with a large value resistor in series with the LED, that won't light when the voltage is too low.

Michael

There are negation gates (ICs) that can be used for this. give you an output if there is none and vice versa... basic digital electronics. or you could use a relay.

12-06-2006, 11:57 PM	#7
ramy_zohair Variable Bitrate Join Date: Sep 2004 Location: Sharjah, Emirates Posts: 394	Quote: Originally Posted by Wiredwrx I don't think there is a way to trigger/light an LED when voltage drops (a battery dies because/when the voltage drops below a certain level) to a predetermined or specific level, with out being powered. Perhaps you can just add some sort of button, that when pushed, will light an LED, unless it is below a certain voltage. You can do this with a large value resistor in series with the LED, that won't light when the voltage is too low. Michael There are negation gates (ICs) that can be used for this. give you an output if there is none and vice versa... basic digital electronics. or you could use a relay. __________________ Final Touches Car: 2002 Mitsubishi Magna EI CarPC: SP13000, M2-ATX, 512 MB RAM, 120 GB 2.5" HD, X-Fi Sound Card, Xenarc 700TSV, Garmin 18 USB. Audio: 2X15" Rockford Punch Z, 1 Rockford Punch 2-ch Amp, 1 Soundstream Lil Wonder II 4-ch Amp Last edited by ramy_zohair; 12-11-2006 at 11:36 PM.