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1.5v LED flasher

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This circuit is a LED flasher that run by 1.5v AAA battery. Flashing speed can change by changing C1. The circuit consume low current, 20mA when LED be turn ON. Parts list: Transistor BC547 Transistor BC557 LED Resistor 680ohm (2pcs) Resistor 39 ohm Resistor 330K Capacitor 10nF Capacitor 2uF Capacitor 470uF 1.5V Battery

Simple emergency light

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Following circuit is a simple emergency light. when it connected to power supply(adapter) the battery be charged and when the electricity be turn OFF or the adapter be disconnected the LEDs be turn ON automatically . its cheap, simple and useful. you can use a power LED rather than use several LEDs. R2 must be jumped when a power LED used. (as you see in follow video)

Timer with touch switch

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This circuit is a timer that turn ON by touch. When you touch leg 2 of IC the load be turn ON and after 3sec to one hours or more the load be turn OFF.(this period can adjustment by the potentiometer) You can increase this time period by increase the value of capacitor.

How to make a simple light meter

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Following circuit is simplest light meter that made by one NPN transistor,LDR and voltmeter  have good sensitivity to light. you can run it by 5 to 30 volt (according to type of voltmeter)

Simplest PWM DC motor speed controller

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PWM DC motor speed controller use in different area such as cordless drill, children car, solar car, etc. following circuit is simplest PWM DC motor speed controller made by IC 555 and  MOSFET. you can use other N-channel MOSFET such as IRZ46N or IRF520 you must use heat sink for MOSFET    

Simple password circuit using IC 4017

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This is a simple password circuit that can run any electric device when a true password inserted the circuit based on IC counter 4017 that used in sequentially LED flasher and other applications. When you press S1 then S2 then S3 then S4 the relay be turn ON otherwise the relay stay turn OFF. the keys that connected to pin 15 of the IC reset the circuit so if you pressed 2 first pass code correctly by pressing any false key the circuit reset the first correct codes. you have to configuration the S1 to S4 as you want for example if you want to make the password 7460 so you have to connect S1 to number 7 in the keypad and S2 to number 4 and S3 to number 6 and S4 to number 0 in the keyboard. in following video you can see how it work. Parts list: IC4017 Relay 12v Transistor 2N3904 or any other NPN transistor Diode 1N4007 Diode 1N4148(5pcs) Capacitor 100uF Resistor 100K(2pcs) Resistor 10K Resistor 1K Push button switch(10pcs) LED

Traffic light using IC4017

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This circuit is a simple traffic light, composed of IC 4017 and IC 555 The speed can change by P1 you can add more LEDs for each color Parts list: IC 4017 IC 555 Diode 1N4007 (9pcs) Potentiometer 1M LEDs(12pcs for each color) Capacitor 10uF 25v Resistor 100k