This circuit uses two National Semiconductor LM3914 dot/bar-display-driver ICs to implement a two-digit, 0 to 5V LED voltmeter that mimics a subranging flash ADC. An LED bar graph comprising five LEDs ...
This LED DC voltage indicator circuit is a voltmeter, rather than simply a battery tester. As such it may measure voltages as low as 3V. It utilizes venerable LM741 operational amplifiers applied as ...