Vacuum Tubes Valves
Musical & effects
Yagi Uda Antennas
Metal Detector Circuits
Liquid Sensing Circuits
Light Sensing Circuits
Voltage Detector Circuits
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
Analog to Digital
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
Light Laser LED Circuits
12v LED Light
This circuit makes a nice lamp that consumes little power, runs cool, and has an incredibly long lifetime. The lamp puts out a warm yellow shade of light, the color may be adjusted by changing the number of red or green LED strings. Operating Voltage: 12V DC Operating Current: 80ma approx.
Circuit switches bipolar LED
The circuit in Figure 1 represents one method to switch a bipolar, two-color LED using an SPDT mechanical switch or relay. This circuit wastes power and does not work properly if the power-supply voltage is not substantially more than the sum of the LEDs` forward voltages. The circuit is, therefore, marginal, to the point of being unusable, with...
Christmas LED lights circuit with 555 timer
This circuit sequence through a pattern of Christmas lights to turn on and off each string of lights, one at a time. After sequencing through all strings, the circuit turns the last string off, then turns all strings on, and then off, before repeating the pattern. Some simple wiring changes will let you set up other patterns. This circuit...
1.5 Volt LED Flasher Circuits
The LED flasher circuits below operate on a single 1.5 volt battery. The circuit on the upper right uses the popular LM3909 LED flasher IC and requires only a timing capacitor and LED. The top left circuit, designed by Andre De-Guerin illustrates using a 100uF capacitor to double the battery voltage to obtain 3 volts for the LED. Two sections of...
White LED Drive Circuit
A minimum number of parts yields a compact switching converter that can provide sufficient voltage to drive white LEDs. The resulting lamp is much more efficient, in terms of lumen hours per pound of battery, than incandescent bulbs, and because the color of the light is determined by fluorescence of phosphors within the LED assembly, the color...
200 LEDs Christmas Lights circuit
This simple and inexpensive circuit built around a popular CMOS hex inverter IC CD4069UB offers four sequential switching outputs that may be used to control 200 LEDs (50 LEDs per channel), driven directly from mains supply. Input supply of 230V AC is rectified by the bridge rectifiers D1 to D4. After fullwave rectification, the average output...
The digital clock of circuit, has as base one IC, the MM5314N, in which are contained all the circuits that need. The IC1 collaborates with six Display of common anode, that are not critically as materials. You can select what dimension, you want it is enough you adapt pins their in the circuit. The display are drive by a system of polyplexis...
3 LED Car battery Indicator
The operating principle of the circuit is very simple. The first Led D1 is placed in series with the resistor R2 and diode D4.An only be lit this LED indicates that the battery is ypofortismeni. For this reason Led D1 is red. If the voltage is greater than 12V, then netting R5 Z3 turns the transistor TR1, so the glows and Led D2 indicates that...
VU Meter with UAA180
This circuit of measurement of level uses the UAA180 of SIEMENS and a circuit of rectification of precision, round the IC2B. The calibration has become in steps 3db from the one Led in the other, ensuring, a very good rate of precision, in the measurement of entering acoustic signals. The Led can be square, thus when they are placed the one by...
AVR LED RF Field Strength
Useful as a transmitter tune-up meter or an RF sniffer, this is an RF field strength indicator that is loosely based on the Broad Band RF Field Strength Probe, described elsewhere. It detects RF via a square law detector, basically its a crystal set with gain. The bias circuit for the detector is significantly modified from the probe to reduce...
Luxeon Star LED driver with MAX1709 IC
Anyone who has ever dealt with construction of low-voltage-fed inverter realized that this is no easy task. The shrinking supply voltage decreases rapidly transferred power and efficiency. Samokmitající converters fail to provide sufficient power to drive control for the purpose of unduly complex. Involvement of the drive, greatly simplifies the...
Using white LEDs
The yellow LEDs are on a small PCB, which are easy to remove. On the PCB there is 3 yellow LEDs and 4 diodes. Pictures of the PCB can be seen here : Top-side - Bottom-side. The schematic is as follows : You now remove the 3 LEDs and the 3 normal diodes (the ones who are in series). I actually only removed the outer 2 as the remainder is...
Processor`s PWM output controls LCD/LED driver
The circuit comprises simply the PWM source, capacitor C, and resistors RD and RW. For CMOS circuits, you calculate the open-circuit output voltage as VCONT=D½§VDD, where VCONT is the control circuit`s output voltage, D is the PWM duty cycle, and VDD is the logic-supply voltage. The control circuit`s output impedance is the sum of the...
LED driver as fault monitor
Using just four transistors and six resistors, this circuit provides switchable, constant-current drive for an LED and indicates both open- and short-circuit fault conditions (Figure 1). And there`s a bonus, too. Control signal VCONT switches the LED on and off. When VCONT is high, Q1 and the LED are off. When VCONT is as low as 0V, Q1 turns on...
Low Cost Alternative to LEDs for Backlighting
The circuit shown in Figure 1 is specifically designed to control a single 1W CCFL. T1, Q1, Q2 and associated components form a current fed resonant Royer converter that produces a high voltage at transformer T1s secondary winding. The CCFL current is the feedback signal to the LTC®1697. The LTC1697 delivers switch mode power to the...
Bicycle weel Light Display with ATTiny26
48 LEDs total, 24 on each side of the board. This gives higher resolution patterns, and they can be seen from both sides of the bike. The LEDs are controlled from a series of 74x373 ICs connected to an 8 bit bus on the microcontroller. As opposed to shift registers, all 48 LEDs can be updated in 20-30 microcontroller cycles, leaving plenty of...
4 Channel DMX512 Driver
This project is a 4 channel DMX512 driver board. It features four power MOSFETs that can be configured to operate in PWM mode or as on/off outputs. The driver can be configured to use any four consecutive addresses across the full 512 channel address range. It can be used to drive LED arrays or low voltage lamps in PWM mode or operate relays...
Auto-Phone dialer for alarm security system
The circuit consists of a small PIC microcontroller, assembly program, and a few other parts to detect a switch closure from an open door, window, or manual push button and then dial the cell phone number, and transmit a steady tone to indicate the source of the call. The circuit uses the pulse dialing system to interrupt the line connection...
Incandescent LED Circuit
This circuit when used with a 555 timer will cause light emitting diodes to turn on and off more slowly. This will make the LEDs appear similar to incandescent lamps.
White-LED driver provides 64-step dimming
The circuit of Figure 1 is designed for portable-power applications that require white LEDs with adjustable, logarithmic dimming levels. The circuit drives as many as four white LEDs from a 3.3V source and adjusts the total LED current from 1 to 106 mA in 64 steps of 1 dB each. The driver is a charge pump that mirrors the current ISET (sourced...
LED flashing with 3909 IC circuit
This project uses a 3909 IC and a few other parts; power is 1.5 volts DC.
LED Flasher with 555
This is a very basic circuit for flashing one or more LEDS and also to alternately flash one or more LEDs. It uses a 555 timer setup as an astable multivibrator with a variable frequency. With the preset at its max. the flashing rate of the LED is about 1/2 a second. It can be increased by increasing the value of the capacitor from 10uF to a...
Circuit drives and quantities LEDs
The circuit mixes LEDs of different forward-bias requirements, yet keeps the loads reasonably well-balanced through use of a current mirror comprising transistors Q1 through Q4. It also eliminates the need for a separate current-limiting "ballast" resistor on each LED or string of LEDs and provides a common control point (IC1`s ADJ pin) for...
LED Flash Driver with HT2050
This circuit is based around HT?2050 manufactured by HOLTEK semiconductors. It is a low cost, low-power C-MOS LSI designed for lamp andLED flash driver. It requires minimum external components.You can operate it with just two AAA cell or 3v Battery.Circuit has five flash outputs with 10mA drive capability that can implement random or sequence...
LED or bulb flickers
This may well be the world`s only discreet logic circuit to generate truely random output. It makes an excellent candle flicker light for your haloween pumpkin, and looks much more authentic than a shimmer light wherever a good a simulated flame effect is required. It flickers even more authentically than a candle in a light breeze.
LED Night Lamp
This circuit is usable as a Night Lamp when a wall mains socket is not available to plug-in an ever running small neon lamp device. In order to ensure minimum battery consumption, one 1.5V cell is used, and a simple voltage doubler drives a pulsating ultra-bright LED: current drawing is less than 500µA.Ultra-low current drawing 1.5V battery...
Low battery indicators with LED
For a transistor to conduct, it requires a voltage of about 0.6 between its base and emitter. This voltage is applied from the wiper of the 47K pot. Now if the pot is at minimum, this voltage is across the 22K, so the 47K will have about 1.28v across it - or 1.88 across the pair. Add the 3V9 from the zener: this will require a battery voltage of...
Heart of LEDs
For those who dont like microcontroller projects, pretend the micro is a dedicated LED driver IC that just happens to have been designed to control 30 LEDs in the shape of a Heart (what a stroke of luck!). And it wont be declared obsolete just after publication like a purpose designed IC might be! Using a PC parallel port to control external...
8 Channel PWM LED Chaser PIC 16F628A
This neat little circuit provides 8 LEDs directly driven from the PIC along with a single mode control switch. The firmware elsewhere on this page drives the LEDs with a 5 bit PWM signal providing each of the 8 LED channels with four levels of intensity; off, dim, mid, bright. A number of sequences are programmed into the firmware to provide...
Brakelight Stop flasher
This is basically a flasher circuit modified to turn on and off a bulb instead of a LED. It uses a 555 timer IC working as an astable multivibrator. The flashing rate can be varied from very fast to a maximum of once in 1.5 sec by varying the preset VR1.
Single cell lights any LED
The circuit in Figure 1 allows you to light any type of LED from a single cell whose voltage ranges from 1 to 1.5V. This range accommodates alkaline, carbon-zinc, NiCd, or NiMH single cells. The circuit`s principal application is in LED-based flashlights, such as a red LED in an astronomer`s flashlight, which doesn`t interfere with night vision....
Power LED mood Lamp
A good way to mount the circuit board is to use a hot glue gun to "mold" the circuit underneath the lamp housing. There is plenty of space there for your board. At the next photos you can see the circuit board mounted on the small 31cm IKEA Mylonit Lamp. It's clear that current changes as colors are changing. As you can see the max current...
Light Sensing Circuits
Light Dimmer 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