How to Make a Simple Boost Converter with 555 Timer?

We may come across many circumstances where we need 12V from a 5V (as from USB ports which only provide 5V), but it may not be sufficient to drive all the circuits. To face such situations we are introducing a dc to dc boost converter circuit which can generate 12 volt from 5 volt. Today boost converter applications are used in different devices like dc dc power supply, dc-dc converter module, isolated dc dc converter etc. The main component used for this circuit is a 555 timer IC operating in astable mode. It generates a square pulse which is then given to a simple transistor inverter to get inverted outputs. These two outputs will drive a voltage pump which increases the voltage level by series addition. However this 555 timer boost converter has a disadvantage of low output current so it can’t drive high current devices. To get more current you have to use a step up converter circuit that we will introduce later.

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Real Time Clock Circuit using Mircocontroller

Here I am going to teach you a simple circuit of 24 hour digital clock display that can also be used in 12 hour format by simply loading the corresponding clock program. You can download the hex files for both 12 hour format and 24 hour time system from the link given in this article. Coming to the technical part, main component of the circuit is a PIC16f84A microchip; it generates the one second clock to run the device and also controls the seven segment display. Three push buttons are also provided to set the time; one for reset by which you can reset the complete circuit as it is connected to the reset pin of PIC microcontroller. Other two push buttons are for setting hour and minute. By Pressing these button continuously you can increment hour and minutes.

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Automatic Rain Sensing Wiper System using 555 Timer

Have you seen Audi, Lexus or Ford rain sensing wipers and wondered how they work in these vehicles? They are handled by sensors at the center of the windscreen which detects rain water and turns on the wiper motor. Here is the working of rain sensitive wipers with circuit schematic. The main component of this circuit is a 555 timer IC that works in monostable mode. Two metal sheets fixed at a small distance apart are used as rain detector sensors. From the working of a monostable 555 timer, a negative voltage on the trigger pin will cause a high output. So when it rains, trigger pin gets a negative voltage. Output of one shot 555 (monostable) is connected to a relay through a transistor. The transistor acts as a switch for the relay to turn ON the wiper motor during rain.

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Multi Channel Remote Control System

Here is a hobby circuit of a multi channel remote control system, by which you can control 8 different appliances. The main sections of this multi channel remote control circuit are the RF receiver and transmitter. By using this circuit we can control 8 devices, each of them independently by pressing the push buttons. When the button is pushed, corresponding relay is turned ON and is turned OFF on the next push. Here the relay load current is dependent on the relay used. A serial encoder IC HT12E and a serial decoder IC HT12D are used, where the encoder IC encodes the parallel data to serial and decoder IC decodes the serial data to parallel during the wireless transmission. You must need a regulated power supply of 5 volt for this circuit because ICs 7476 and 74138 requires 5v for its operation. The main advantage of this system is that it does not require a ‘line of sight’ as compared to IR remote control systems; also it gives longer distance control.

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555 Touch Sensor

How to make a touch sensor? Here is a simple DIY touch sensor circuit diagram using 555 timer monostable mode. Touch switch is only a conducting metal sheet that acts as touch sensor. The 555 touch switch is not a touch capacitive sensor; it is only a metal touch sensor button. Using this you can turn on and off devices by single touch. Here we are using a JK flip flop IC 7476 that is connected as T-flip flop. The output of T-flip flop is connected to the base of transistor to turn ON the relay so as to control high current electrical devices such as fan, motor, lamps etc.

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How to Build your Own USB PIC Programmer?

This DIY PIC programmer is a continuation of our PIC programming basics tutorial. By using this USB PIC programmer, you can program microchip PIC series of 10F, 12F, 16F, 18F, 24F, 30F. This is also an EEPROM programmer as it supports 12Cxx EEPROM. The main component of this PIC microcontroller programming circuit is a PIC182550 microcontroller which controls the overall circuit. Serial port PIC programmers are the widely used PIC chip programmer Kit, but since laptops have no RS232 ports they require an USB to RS232 converter.

Recommended for you:

• PIC microcontroller Beginner's guide: Basic connection circuit 
• How to burn or program PIC Microcontroller? 

Now one of the main advantages of this circuit is that it does not require any external power supply, instead it uses USB power. It generates programming voltage of 13V through voltage multipliers. Linux PIC programmer software is also available for burning. You can program micro controller like pic16f84a, pic16f877a, pic18f4550, pic16f628a etc. and make your micro controller programming easier.

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12v Battery Charger Circuit with Auto Cut off

This is a simple DIY charge controller schematic posted in response to a request by one of our readers on our facebook page. The main component of this auto battery charger circuit is a 555 timer which compares the voltage in the battery. It turns ON the charger if the battery voltage is below the variable preset voltage (12 volt chosen here) and turns OFF the charger if the voltage reaches 13 volt. The battery charging voltage of the charger can be varied by adjusting the variable resistor and maximum charging is limited by a 13V zener diode on the fifth terminal of 555 IC.

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