Level Voltage Indicator | Electronic Project Circuits

Posts Tagged ‘level voltage indicator’

Low Supply Rail Detect voltage

Here’s a simple low supply rail detection circuit that costs peanuts and takes just 20 minutes or so to make. Its power consumption is quite low, so it could easily be built into battery-powered devices. Instead of using an op amp, the circuit is built around three low-cost transistors (Q1-Q3). Diodes D1-D3 form a 1.8V voltage reference (Vref) for the emitter of Q1. If the voltage across the voltage divider formed by R1 and VR1 is less than this, Q1 turns on and supplies Q2 with base bias current.
This turns on Q3 in proportion to this bias current which then drives LED1. The brightness of the LED gives an indication of the severity of the low voltage condition. The brighter the LED, the lower the supply voltage. Trimpot VR1 is adjusted so that LED1 just comes on at the desired low-voltage point. The current consumption is typically less than 2mA when LED1 is off. Finally, the value shown for RLED is suitable for 6-12V operation. For other voltages, RLED can be calculated using the formula RLED = (Vcc – 1.8)/0.01 (this equates to a current of about 10mA).
Author: Trent Jackson
Source: http://www.extremecircuits.net/2010/05/low-supply-rail-detection.html

Be the first to comment - What do you think? Posted by admin - March 22, 2011 at 10:25 am

Categories: Detector, LED Flasher, Meter Tags: battery check, level voltage indicator

Integrated battery level indicator with 3 level led

This circuit is simple battery level indicator circuit. Which be simple complicated can see that the circuit has will LED keep for display arrive at 3 step.
The work of the circuit be this circuit was fixed come to give a temple volt usual that about 11V-14V. Which will the level volt normal, if level voltage a little 11V more make LED1 red stick bright. If voltage 11V more than but 14V not exceed make LED1 the red and LED2 green stick bright. Because voltage that 11V exceed have current flow through R1 and ZD1 go to encourage a pin B of Q1 make Q1 work LED2 bright. But if level voltage of power supply 15V exceed make LED 3 both of stick bright. Because of volt reed source that 15V have current flow through R4 and ZD2 go to encourage pin B of Q2, It make Q2 work LED3 , then stick bright.

Be the first to comment - What do you think? Posted by admin - July 4, 2010 at 4:23 am

Categories: Battery, Detector, Meter Tags: battery level indicator, level voltage indicator

Voltage detector by IC TL431

This be simple check pressure level circuit, with integrated number circuit TL431. When use power supply 5Volt in digital circuit. The general feeding signal input be high class logic be High, make have voltage way output be 5 Volt. But enough feed the level logic be Low as a result, make output level voltage be 1.8V this circuit uses the equipment a little 2 pcs. only just as a result can be usable already.