The circuit described below is used to on and off the motor just by clicking your TV or AC remote. This low cost circuit is based on IR sensor, transistor with few more components to “on” the relay and a motor is connected with the relay which also become “on”. After receiving the second pulse motor become “off”. You can control your motor from 5-7 meters range. It can be operated with all most all the remotes present in home as it works on 38Khz frequency. You do not require to move from your place, just press the remote device become “on” and “off” respectively by getting signals from remote. The circuit also provides you the visual indication (“on” or “off”) of the device with the help of LED.
Visitor Counter
The circuit developed here will count the number of visitor entering or exiting from door of auditorium or hall or any other place. Depending on the interrupt from the sensors, the system identifies the entry and exit of the visitor. On the successful implementation of the procedure, it displays the number of visitor present in the room. Therefore it can be economically implemented in all the places where the visitors have to be counted and controlled. This circuit is good enough for only one person entering at a time. It will also give you visual indication of circuit with the help of LED. It is operated at wide range of temperature from 5V to 20V. The big advantage of the 4026B counter IC is that it can drive a 7-segment display without needing a decoder driver IC. It will count the number of visitor up to 99 which can be increased by cascading more 4026 IC.
Speed Control of DC Motor
It is a simple circuit with the help of which you can control the speed of DC motor. You can also use it control the speed of windscreen wipers used in automobiles or it can be used in toys. Easy to install because of less components used and works well on wide range of power supply from 5V to 12V. This circuit is based on single IC that is NE555 which work as a-stable multi-vibrator. In this mode 555 timer is not stable and its output is continuously changes from low to high or from high to low. This continuous change from one state to another (high to low and then back to original state) produces a continuous square wave output.
Reverse Parking Sensor
There are times when it is difficult to judge the distance while reversing the car or while parking. If someone is there to help you that is great but in situations when you are driving alone then what will you do? Or you are a new driver and cannot judge the distance? This circuit will solve all these problems. You can easily install at the back side of your car. Operated at 5V power supply and can also recharge batteries. You can also use them as shadow alarm at doors to protect your car. When shadow of a intruder fall on it will also give you alarm. This alarm will provide you the musical sound that’s why it will not tease your ears. Main components of this circuit areLM358 IC, LDR, UM66 IC, speaker and few more discrete components.LM358 consist of two independent, high gain operational amplifier in one package. Important feature of this IC is we do not require independent power supply for working of each comparator for wide range of power supply.
How to display numbers and alphabet on 7 segment display?
Seven segment displays nowadays are commonly used in place of dot matrix display. They have found their use in places like microwave or fancy toaster oven or the same on washing machine but before using them in all these places you need to interface the 7 segment display with microcontroller or some more hardware will be required. But with the basic knowledge of 7 segments display you can use it in front of your shop or you can display your name on it. 7 segment displays numbers from 0 to 9 and some alphabets.7 segment display are labelled a to g and decimal point is usually known as DP. DP is the common point. In common cathode display they are connected to ground and rest pin are connected to supply. Similarly in common anode DP are connected to supply and rest are connected to ground. You can also use more than one display according to your requirement.
Automatic water level controller
Water level controllers are quite common nowadays. This circuit is based on popularly used IC555 IC. Water level controller circuits have these advantages: Mostthe circuit only display the amount of water present in circuit, but this circuit will “on” and “off” the motor according to the level of water present in tank. It will not automatically stop the motor when tank is fill but it will “on” the motor when water in tank reaches below a specific point. It can be easily installed in over headed tanks because of less components used in circuits. It prevents the wastage of water due to over flow of tank. Can be operated with the help of 12V battery or adaptors (converts 230V AC to 12V DC) readily available in markets.
Johnson Counter: How to use IC CD4033
CD4033 is a Johnson counter IC commonly used in digital display. It has a 5 stage Johnson decade counter with decoder which convert the Johnson code to a 7 [[wysiwyg_imageupload::]]segment decoded output. Means it will convert the input into numeric display which can be seen on 7 segment display or with the help of LED’s.Advantage of this IC is it can be operated at high voltage of 20V. But is highly sensitive, can detect emf present in the atmosphere and is sensitive to static charge also. When you touch your finger at its input terminal its counter get started therefore care should be taken while using it. It can be used in various application like in 7 segment decimal display circuit, in clocks, timer etc. To understand its working first have a look on its pin diagram. Read more to find out how it is can be used in various applications.