555 Circuits – Light Detector
555 Circuits – Light Detector This circuit detects light falling on the Photo-cell (Light Dependent Resistor) to turn on the 555 and create a tone that is delivered to the speaker. Pin 4 must be held below 0.7v to turn the 555 off. Any voltage above 0.7v will activate the circuit. The adjustable sensitivity control […]
555 Circuits – Amplifier
555 Circuits – Amplifier The 555 can be used as an amplifier. It operates very similar to pulse-width modulation. The component values cause the 555 to oscillate at approx 66kHz and the speaker does not respond to this high frequency. Instead it responds to the average CD value of the modulated output and demonstrates the concept of pulse-width modulation. The […]
555 Circuits – Metal Detector
METAL DETECTOR This circuit detects metal and also magnets. When a magnet is brought close to the 10mH choke, the output frequency changes. Jan 28, 2016rare
Dark Light Activated Relay
Dark Light Activated Relay None of the parts are critical and easy available. The potmeter adjust the trigger ‘on’ level. The diode in the diagram shows to be 1N914. This is ok if you have a light-duty relay, also the 1N914 is a signal diode so actually does not qualify. Use a 1N4001 (or better) […]
Automatic Fan Switch
Automatic Fan Switch The op-amp used is a readily available LM339. This IC contains four op-amps but we use only two of them. Use the others for spare or do something else with it. For the thermistor I used a small, very expensive ($52), glass-encapsulated type because I had it laying around but almost any […]
Heat Sensor, Automatic temperature control
Heat Sensor, Automatic temperature control The Thermistor, or NTC (Negative Temperature Coefficient) of 10K, is a standard type. Most types will work. The one in the diagram is a 10K model made by Fenwal . The resistance lowers as the surrounding temperature increases which affects the output (pin 6) and energizes the small relay and […]
Alternating ON-OFF Switch Electronic Circuit
Alternating ON-OFF Switch Use this circuit instead of a standard on-off switch. Switching is very gentle. Connect unused input pins to an appropriate logic level (I used ground). IC1, the MC14069 (or 4069) is a regular Hex-inverter type and is constructed with MOS P-channel and N-channel enhancement mode devices in a single monolithic structure. […]
Introduction to arduino
Introduction to arduino What is Arduino? A microcontroller board, contains on-board power supply, USB port to communicate with PC, and an Atmel microcontroller chip.It simplify the process of creating any control system by providing the standard board that can be programmed and connected to the system without the need to any sophisticated PCB design and […]
Arduino UNO Pin Diagram
Arduino UNO Pinout Diagram Arduino UNO pin map that you can use in your project. Jan 26, 2016rare
ATmega8-Arduino Pin Map
ATmega8-Arduino Pin Map Below is the pin mapping for the Atmega8, the original chip used in early Arduinos. Jan 26, 2016rare
Arduino Project – Model Traffic Signal
Arduino Project – Model Traffic Signal So now we know how to set a digital pin to be an input, we can build a project for model traffic signals using red, yellow, and green LEDs. Every time we press the button, the traffic signal will go to the next step in the sequence. In the […]
Potentiometer 3D Inventor Drawing
Potentiometer 3D Solidworks Drawing ; The main components of the electronic potentiometers 3D Autocad Inventor drawing file. Jan 24, 2016rare
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