Vacuum Tubes Valves
Musical & effects
Yagi Uda Antennas
Metal Detector Circuits
Liquid Sensing Circuits
Light Sensing Circuits
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Air-Gas Detection Circuits
Human Sensing Circuits
RF & Radiation
Optical Sensing Circuits
Free Energy Circuits
AC to DC & DC to DC
Solar Cell Circuits
Micro Power Circuits
Switching Power Supplies
Light Laser LED
Digital to Analog
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Data Bus Circuits
Voltage to Pulse
Current to Voltage
Frequency to Voltage
RF Converter Circuits
Sine to Square Wave
Voltage to Current
voltage to frequency
Period to Voltage
Video Wall circuits
TV Video Circuits
Motor Control Circuits
8051 / 8052
PCB CAD Software
Car bike Circuits
555 Timer Circuits
Remote Control Toy
H Bridge Circuit
Interconnection & Timing
Digital Signal Integrity
Digital & Bipolars
Sensors & Detectors
Regulated Power Supply
4 Band Resistor
5 Band resistor
6 Band resistor
Relay Coil Energy Saver
Some relays will become warm if they remain energized for some time. The circuit shown here will actuate the relay as before but then reduce the â€˜hold cu..
SMPSU With A Relay
Switched mode power supply units (SMPSUs) are popular but difficult to build oneself as well problematic when it comes to understanding their design princ..
Reducing Relay Power Consumption
This circuit proves that microcoprocessors, PCs and the latest ultra-accurate DACs are overkill when it comes to controlling four relays in sequence in re..
Water Pump Relay Controller Circuit Schematic
By means of a Relay, employed to drive a water pump, this circuit provides automatic level control of a water reservoir or well. The shorter steel rod is the water high sensor, whereas the longer is the water low sensor. When the water level is below both sensors, IC1C output (pin #10) is low; if the water becomes in contact with the longer
Rs 232 Relay Control Board
Can be interfaced to other adapters Keypad adapter (Optional) or RF receiver (Optional) or Via the Net (Optional) Can be adapted to operate other external attachmen..
How hard it would be to convert the relay in this design to a triac It switches a 120v Ni-chrome wire that is 60ohms. Thanks for any help you can offer. Your right i apologize. The ic powers off of a 12v transformer. However there is a 120v neutral and line onboard that feeds a 12v voltage reg
what relay should i use parallel port
Control a car toy. The toy car is controlled via a controller that is connected to it via a wire, so it`s not radio controlled. I would like to use relays to control toy via parallel port. I think there are many relay types and models, and I would like to know which one is the most suitable one for this case. [ I never used relays before] Also,...
microcontroller driving relay
I usually use an NPN Bipolar transistor to do the relay switching, mainly because my relays are 12v coil rated, but it also keeps everything nice and seperated. and yes i add a diode. with no problem. ( do I or did I need to drive it with a transistor ) but it seam like radio shack is getting out of the parts business. I`ve got to place a order wit
Light Dark switch activated relay circuits
This Light Dark switch activated relay circuits schematics are the simplest electronic circuits that can help you to activate other electronic device at the light or dark. This Light Dark switch activated relay circuits are very simple and require one electronic relay and other few common components that are not critical. For electronic project
Relay Sequencer Board
A relay sequencer is used in a radio transverter and is use to activate particular stages in order after short delay. This project describes how to build this sequencer. It has the following features. This stage is used to switch the output / input of the driving radio to the corresponding RX IF output or the TX IF input depending the current stat
Common ground for different voltages in relay circuit
Hello, My goal is to control a 12 VDC device (on/off) from a microcontroller using a relay card. The relay needs 12 VDC operating power (I use the..
need help with latching relay circuit
Hey guys, need some help with a project. Im pretty good with 12v electrical wiring but am having trouble figuring this out. Im building a switch panel ..
Relay Computer Two
The simple relay adder was built using free NOS relays sometime in 2005, but my goal was to someday build a more elaborate one that could run programs but notfill up a room like the early computers. Harry Porter built an incredible 415-relay computer which can be seen at this page: I never thought I`d fully understand how his computer worked, let
12V Time Delay Relay Circuit
Protect your equipments with this tiny 12V time delay relay circuit. The SMPS based power supply of these modern electronic devices is vulnerable to spikes..
Light Operated Relay Circuit
This light sensitive circuit can operate a relay to switch on lamps or any AC loads when it senses darkness. It is ideal to use as switch less night lamps..
DIY Solid State Relay
One advantage of solid-state relay (SSR) over conventional electro-magnetic relay (EMR) is its tear and wear free operation. S201S01 from Sharp is a good e..
Transistor Relay Driver Circuit
One of the serious problems in relay operated circuits is the relay clicking or chattering during the on/off of the relay driver transistor. This problem i..
Temperature Controlled Relay Circuit
This temperature controlled relay circuit is a simple yet highly accurate thermal control circuit which can be used in applications where automatic tempera..
Temperature Relay Circuit
This simple temperature relay circuit can be used to signal a fire or setpoint for temperature monitoring function. You need to adjust P1 so that T1`s base..
Relays have been around for a long time and though often now replaced with solid state switches, they have unique properties that make them more robust tha..
555 Voltage Doubler Relay Driver
These novel relay driver circuits have the ability to pick up a relay with a coil voltage rating equal to double Vcc. After pickup, the relay armature is h..
Light Activated Relay with 555 Circuit
This light activated relay circuit presented here uses the 555 timer IC and a light dependent resistor or LDR to form a light sensitive relay in an intruder alarm system or for switching on a lamp at Sun set and off at Sun rise. Potentiometer R1 value must be chosen and then adjusted that under normal conditions when the light is falling on the LD
Microcontroller Relay Driver and Interface
Many microcontroller designs typically mix multiple interfacing methods. A microcontroller (µC) system can be viewed as a system that reads from inpu..
Run/Stop Relay Circuit
Safety is a major concern in a good many motor-driven applications. This is true in industrial applications where motion starts when power is applied and e..
4541 Timer Relay Circuit 0.3 second to 10 hours
In order to start the timining you have 2 possibilities: you either connect the START point to ground GND and in this case the timer starts when you connect it to the voltage supply or you can place a switch to start it.
interfacing relay 8051 keil c
In some electronic applications we need to switch or control high voltages or high currents. In these cases we may useelectromagnetic or solid state relays. For example, it can be used to control home appliances using low power electronic circuits. Anelectromagneticrelayis a switch which is used to switch High Voltage or Current using Lowpower...
Car Relay Charger circuit
Hi Folks, I`m new to the forum and a bit of an electronic newbee, (from an engineering technical perspective, though have tinkered with circuits/schema..
Clock Controlled Relay
You can switch on a load such as Water pump automatically at the required time through this Clock Controlled Relay or also known as Time Delay Relay. It uses an ordinary clock to trigger the circuit to switch on the load
Audio amplifier output relay delay
This is a simple circuit which I built to one of my audio amplifier projects to control the speaker output relay. The purpose of this circuit is to control the relay which turns on the speaker output relay in the audio amplifier. The idea of the circuit is wait around 5 seconds ofter the power up until the spakers are switched to the amplfier outp
Dual Relay Driver Board
Stepper Motor Circuits
Remote Control Circuits
Direction Finder Circuits
Power Control Circuits
Motor Control Circuits
Ultrasonic distance finder circuit
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
Digital Signal Integrity
Interconnection and Timing of Digital Circuits
CMOS Circuits Tutorial