FSK means Frequency Shift Keying. It’s one of the Modulation Scheme used to Transmit Digital Data using High Frequency carrier signal. In this Modulation Scheme bit 1 is transmitted using one carrier signal and bit 0 is transmitted using another carrier signal like· Bit 1 (logic high) is Transmitted using Carrier Frequency Fc1· Bit 0 (logic low) is Transmitted using Carrier Frequency Fc2It means Series of bits (bit stream) are transmitted with two different carrier signals used for bit 1 and bit 0.
Timer Operated Relay with Digital Display
The circuit presented here operates a relay for Fixed Timer Interval. So the device or machine connected with relay operates for same time. The device once switched ON, automatically switches OFF after Fixed (set) Time Interval when relay switches OFF. The Time Interval can be varied and it is displayed on 7 Segment Display. This kind of circuits can be used in many applications where it is required to operate any device or machine for Fixed Time Interval.
Simple RPM Counter using IC 555
RPM counters are used to measure Speed of Motors (AC/DC) or any Rotating Object. They measures and indicates current Rotating Speed of Motor. They are very essential in applications like Speed Control of Motors and close Loop Control System. Such industrial RPM counters are very accurate made up of microcontroller or microprocessor.
DIY: LASER Based Pulse Transmitter and Receiver
The circuit presented here transmits pulses wirelessly to long distance (more than 20 meter) using keychain LASER (readily available in market). A transmitter generates continuous pulses that are fed to LASER. LASER blinks at the rate of pulse frequency and emits light pulses. LDR on the receiver side, detects this light pulses and reproduces it at the output. So the same pulses that are generated at transmitter side can be received at receiver side to longer distance.To begin with the first thing that is required for this project is to prepare LASER. So let us start with how to prepare a LASER. LASER key-chains available in the market are like this. To prepare it for the project we need to take out its anode and cathode terminals to provide pulses. In order to remove button cells and keychain part from backside of the keychain. You will see one small spring, which is cathode terminal. Connect one wire with this as shown in the figure below.
ASK Modulator using 555 Timer IC
ASK means Amplitude Shift Keying (also known as ON-OFF keying). It’s one of the Modulation Scheme used to transmit Digital Data using High Frequency carrier signal. It’s very simple and popular method. It transmits 1’s and 0’s of Digital Data by transmitting carrier or no carrier like · Bit 1 (logic high) is Transmitted with carrier frequency Fc· Bit 0 (logic low) is Transmitted with no carrierMeans series of bits – bit stream is transmitted as carrier ON and carrier OFF. That’s why it is also known as ON-OFF keying.
Simple Stepper Motor Driver using 555 Timer IC
The circuit presented here rotates stepper motor and varies its RPM (speed). It does not use any micro controller (or micro processor) or any programmable digital device also it does not require any software program to generate sequence of pulses. It drives stepper motor using simple, easily available and commonly used components and ICs like IC555, decade counter, OR gate, current driver chip etc. That is why the name given simple stepper motor driver.
Simple 2 Digit Auto-Manual Counter
The circuit presented here counts from 00 to 99 and displays it on two seven segment displays. It can work as free running counter in auto mode or it can count manually when button is pressed. In auto mode it gets continuous pulses and counts continuously at a rate of 1 Hz. That means the count is updated at every second or in other words counter displays time in seconds. This counting rate can be changed by changing pulse frequency. In manual mode, the count is incremented when push button is pressed manually. So it can be used to count up to 100 (from 0 to 99) as per manual requirement.The counter circuit is made up of decade counter cum display driver chip CD4026. The pulse circuit is build using IC555. The circuit can be used in many applications like object counter, frequency counter, RPM counter, stop watch timer, token count display and many others.
Timer Operated Relay with Digital Display
The circuit presented here operates a relay for Fixed Timer Interval. So the device or machine connected with relay operates for same time. The device once switched ON, automatically switches OFF after Fixed (set) Time Interval when relay switches OFF. The Time Interval can be varied and it is displayed on 7 Segment Display. This kind of circuits can be used in many applications where it is required to operate any device or machine for Fixed Time Interval. Like· The Alarm Signal (or Bell) once triggered, remains ON for Fixed Time Interval and then shuts off automatically· In Manufacturing Industries the Motors have to be rotated for Fixed Time Interval once start button is pressed. It stops automatically when time period is overTime operated relay circuit is build using IC555. To display the time period in seconds 2-digit decade counter is build using CD4026 chip. Another IC555 is used to provide 1 Hz pulse to update time period after every 1 sec.
Timer Operated Relay with Digital Display
The circuit presented here operates a relay for Fixed Timer Interval. So the device or machine connected with relay operates for same time. The device once switched ON, automatically switches OFF after Fixed (set) Time Interval when relay switches OFF. The Time Interval can be varied and it is displayed on 7 Segment Display. This kind of circuits can be used in many applications where it is required to operate any device or machine for Fixed Time Interval. Like· The Alarm Signal (or Bell) once triggered, remains ON for Fixed Time Interval and then shuts off automatically· In Manufacturing Industries the Motors have to be rotated for Fixed Time Interval once start button is pressed. It stops automatically when time period is overTime operated relay circuit is build using IC555. To display the time period in seconds 2-digit decade counter is build using CD4026 chip. Another IC555 is used to provide 1 Hz pulse to update time period after every 1 sec.