Led Display Warn | Electronic Project Circuits

Posts Tagged ‘led display warn’

Electronic mailbox front door with ic 555

Living in the current rush to waste time to even have little value. Electronic circuits, so one is important in everyday life.Which saves time and convenience.
For example, this circuit. It gives us no time to wait to check voice mailbox.We see the LED is just enough.
Operation of the circuit. While no letter LDR will receive light from the lamp. The LDR resistance is very low. Resulting in IC does not work.
There is no output from the 3 pin. It make the current flows through R2, LED2 into three legs of IC1.The light LED2.But when a letter in the mail box to shield the light from the lamp. The LDR is not light. LDR will be much resistance.Voltage drop across the LDR is high enough to make IC1 work.
IC1 to produce frequencies from 3 pin. The light LED1.

Be the first to comment - What do you think? Posted by admin - September 8, 2010 at 5:56 pm

Categories: Detector, Electronic Control Tags: electronic mailbox alert, LDR control circuit, led display warn

simple led display warn battery low

Friends may meet the disadvantages of the electrical equipment that uses battery be battery like to finished the climax always. This equipment no help to give battery be finished have power upward again. But wait for warn when battery low be hurried change or charger to first be finished. This circuit designs to come to apply to volt since 3-15V the dot will to begin to show can fine with VR1. When voltage decrease down more location dot keeps LED bright immediately. The electronics part a little also just transistor BC547 and other. It usual Current about 3mA but enough LED bright will valuable about 15mA.

Be the first to comment - What do you think? Posted by admin - June 26, 2009 at 9:49 am

Categories: Battery, Meter Tags: battery meter, led display warn

Fading LED by LM358

This circuit uses op-amps to obtain a triangle wave. The triangle wave causes the Led to slowly get brighter and then slowly get dimmer until it isn’t producing any light. It then gets slowly brighter again. With the components shown each cycle takes about 4 seconds. The capacitor and the 4.7M resistor are the timing components. The circuit works best when a high brightness Led is used.
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Read More Source: http://www.geocities.com/electronics3456/fade.html
Thank you.