LED Circuits
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The circuit consists of two stages. The first stage is a "switch" or cut-off device. It detects a voltage above 0.7v from the solar panel and the resistance between its collector-emitter terminals reduces to a very small value. The 10k resistor allows the.... -
This circuit will flash a string of LED's, typically 16, with direct connection to the mains and with a period adjustable between 1 and 4 seconds depending on the setting of the 22K/1W pot. Operation at 110V should also be possible but has not been tested..... -
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... -
This circuit not only indicates the amount of water present in the overhead tank but also gives an alarm when the tank is full. The circuit uses the widely available CD4066, bilateral switch CMOS IC to indicate the water level through LEDs. When the water.... -
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.... -
Here is a simple circuit which can be used for decoration purposes or as an indicator. Flashing or dancing speed of LEDs can be adjusted and various dancing patterns of lights can be formed. The circuit consists of two astable multivibrators. One.... -
Light emitting diodes are advan- tageous due to their smaller size, low current consumption and catchy colours they emit. Here is a running message display circuit wherein the letters formed by LED arrangement light up progressively. Once all the letters of.... -
This circuit can be used to construct an attractive Christmas Star. When we switch on this circuit, the brightness of lamp L1 gradually increases. When it reaches the maximum brightness level, the brightness starts decreasing gradually. And when it reaches.... -
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.... -
I recently purchased 10 SLM1608 (SLM1606) LED matrix display units from Ebay (you might also contact the seller directly at [email protected]). These are 16x16 LED matrix units with a green and a red LED per pixel allowing each pixel to be switched to either.... -
This circuit uses a germanium diode (marked Ge) as a temperature sensor. I used an OA90 diode but others should do. The 'ring' of Tr1 and Tr2 bias each other. Tr1's collector current is stabilized by the 5v6 zener, causing Tr2 to operate at about 5mA: this.... -
The circuit was designed to work with an audio power amplifier which operated off +18v-0v-18v power rails. The actual voltage used is not too critical except that the feedback is referred to the LED chain which itself is anchored to a +12v rail, hence the.... -
Just to prove that transistors can also be useful in logic situations; this is a data latch and indicator which also is a data switch and has a bidirectional input/output port which can be read or switched. If the second transistor is off, a small currrent.... -
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.... -
This LED thermometer is designed for in home use, to read temperatures between about 60 and 78 degrees Fahrenheit. It is based around a precision temperature sensor IC, the LM34DZ. This sensor require no calibration and can measure temperatures of between.... -
This unit has a single column of LEDs that are spinning in a left to right motion, as it spins a microcontroller keeps track of the exact position of the board. Words are written in the air by flashing the correct bit pattern in the correct location. The.... -
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 consists of a 4047 low-power monostable/astable multivibrator, IC1, used in the astable mode to provide the timing pulses to control the flash rate of the LEDs. To accomplish the astable mode, pins 4, 5, 6, and 14 are connected to +12VDC and pins 7, 8,.... -
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.... -
This schematic uses the 555 timer and the 4017 IC to drive 3 LED, to simulate the trafic lights... -
Often the need to control light switch on the instrument. If napájíme LED source of low DC voltage sufficient to classify a series of LED-resistor of appropriate resistance. Another situation occurs, if a small supply available, or to indicate when the.... -
Many modern audio recorders is now compatible with digital input S / PDIF (Sony / Philips Digital Interface). Devices like CD Changers, MiniDisc recorders, computer sound cards and the like. working with digital signal just with protocol S / PDIF. Digital.... -
White LEDs have a rated current at a voltage drop of about 3.3 to 3.4 V. It is ideal to be powered from the battery voltage which is slightly larger. Then there is the best energy used. In this I used a flashlight battery, Li-ion battery, which lasts the.... -
The article describes a simple and very cheap to drive white, blue or UV LEDs, used for example in small lamps and testers. The cost of components shall not exceed CZK 10. Converters for white LED has been on the pages of journals described quite enough..... -
Presented circuit is very simple. With more sampling, I refrained from using the converter and lamp designed for powering three NiCd or NiMH batteries. Because the voltage difference between the battery and the LED is very small, this arrangement is.... -
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.... -
This Is a capacitor power supply. This is a very small currents of energy-effective, because it has very little loss, much smaller than the miniature transformer. Capacitor impedance is inversely proportional to frequency. This is a great disadvantage when.... -
The device serves to quickly establish the status of an indicative power cells. I built it for his children, so they can determine the degree of self-discharge batteries in a variety of toys. WAS tester designed to test the fast primary (zinc, alcaline).... -
There have described the involvement benefited LM3909 circuit, which is quite expensive. That's why I prefer to use a much cheaper known timer 555th.Involvement of the tree is a very simple scheme is to figure 2 . It is based on several multivibrator used as.... -
The 555 circuit below is a flashing bicycle light powered with three C or D cells (4.5 volts). The two flashlight lamps will alternately flash at a approximate 1.5 second cycle rate. Using a 4.7K resistor for R1 and a 100K resistor for R2 and a 4.7uF.... -
The circuit is a 0-60 second timer using timer 555 and two 4017 for LED driving... -
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....
New Circuits
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This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of.... -
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.... -
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.... -
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.... -
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.... -
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,.... -
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.... -
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.... -
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.....
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