Delay Timer | Electronic Project Circuits

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OFF After Delay Switch by Mosfet

This is OFF After Delay Switch Circuit. It is use Mosfet control the work of LOAD get. By have the work is simple be press Switch (Close) and liberate (Open) S1 an electric bell will loud. After C1 is charger within or change R1 ( the accessory is ) The Q1 is stop work. An electric bell is soundless while delay long follow want. By the change value C1. If be valuable about 1uF delay about minute , but if become 100uF values be hour.
Note: Load that use be Piezo Buzzer or handbag radio or light bulb etc. Be careful don’t use exceed one’s power of Q1. you use a resister builds serial at the dot X for decrease the trend that flow through Q1 go to still Load less. This circuit may in rows think to is simple about , Delay Switch Circuit again interesting circuit please sir.

Be the first to comment - What do you think? Posted by admin - September 20, 2008 at 7:30 am

Categories: Electronic Control, Timer Tags: delay timer, timer controller, Timer Switches

Long Time Delays by CD4040

Generating long delays of several hours can be accomplished by using a low frequency oscillator and a binary counter as shown below. A single Schmitt Trigger inverter stage (1/6 of 74HC14) is used as a squarewave oscillator to produce a low frequency of about 0.5 Hertz. The 10K resistor in series with the input (pin 1) reduces the capacitor discharge current through the inverter input internal protection diodes if the circuit is suddenly disconnected from the supply. This resistor may not be needed but is a good idea to use. The frequency is divided by two at each successive stage of the 12 stage binary counter (CD4040) which yields about 1 hour of time before the final stage (Q12) switches to a high state. Longer or shorter times can be obtained by adjusting the oscillator frequency or using different RC values. Each successive stage changes state when the preceding stage switches to a low state (0 volts), thus the frequency at each stage is one half the frequency of the stage before. Waveform diagrams are shown for the last 3 stages. To begin the delay cycle, the counter can be reset to zero by momentarily connecting the reset line (pin 11) to the positive supply. Timing accuracy will not be as good as with a crystal oscillator and may only be around 1 or 2% depending on the stability of the oscillator capacitor.

Source : http://ourworld.compuserve.com/homepages/
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Be the first to comment - What do you think? Posted by admin - July 25, 2007 at 5:07 pm

Categories: Digital, Timer Tags: delay timer, digital circuit, Timer Switches

Basic Timer By IC Quad Timer LM558

Basic Timer By IC Quad Timer 558
Today I begs for to advise the circuit timer the foundation. By use the integrated circuit number LM558 (IC Quad Timer). Which the structure within like to have IC 555 4 within. If think in the sense of the price has already. As a result economize very that one. For the usability have no differently IC 555 highly very popular extremely. Can use do timer circuit well sir time value can change with change R1 and C1 follow a formula calculates T = 1.1 RC good easy. friends try induce try build play request have fun electronics circuit.