Rongge

This is a simple LED as a diode Rectifier Circuit Diagram. In certain situations where the current is not high, we can use the famous LED (LED) and diode rectifier voltage power circuits. The LED can be used without problem in a rectification circuit, and also works in the power ratings. Pay attention not to exceed the maximum current of the LED in a wave rectifier.  Using LED as a diode Rectifier Circuit Diagram

If you’ve ever tried dimming a LED with a simple potentiometer, you know that the approach does not work very well. Just as with ordinary diodes, the voltage-current characteristic of LEDs is far from linear. The result - depending on the potentiometer setting the LED brightness will hardly change most of the time as the pot is turned and a sudden variation at the end. The best method to tackle this problem is to power the LED from a current source with zero to 100% adjustment range. The circuit shown here is an example. A low-current LED (D1) is used to generate a reference voltage that’s first buffered by one half of an LM358. The actual current source that powers the LED(s) is built around the second opamp in the chip. Circuit diagram: 30-mA LED Dimmer Circuit Diagram The potentiometer allows the output current to be adjusted, with R2 acting as a current sense, the resistor dropping the same voltage as the one obtained from the pot. Using Ohm’s law we find that the maximum current t...

This lamp circuit using ultra-bright white LEDs provides sufficient light for reading purposes while consuming approximately 3 watts of power. In the case of AC mains failure, the battery backup circuit instantly lights up the LEDs. When the power resumes, the battery supply is automatically disconnected and the lamp circuit again works off AC mains. The power supply circuit consists of 0-7.5V, 500mA step-down transformer X1, rectifier diodes D1 through D4 and filter capacitor C1. Regulator IC 7805 (IC1) provides regulated 5V to LEDs, so there is no variation in the intensity of the lamp light even if the mains power supply fluctuates. A total of ten white LEDs (LED1 through LED10) are connected in parrallel across the 5V power supply. Resistors R1 through R10 (each 56 ohms) are connected in series with the white LEDs to limit the current. To increase the intensity of the lamp light, you can add more LEDs in the same manner; a maximum of 15 LEDs can be used for the lamp. LED-Based Read...

This is a fun circuit that can be at parties, for example. The four LEDs flash to the beat of the music. The light organ responds using a microphone to sound.T1 amplifies the signal from MIC. The sensitivity can be adjusted by P1. T4 controls the LEDs.  These are preferably LED's with a high light intensity.MIC is a condenser microphone. The circuit can be powered by a 9 V battery.  LED light Organ Circuit Diagram The 4 Budget This circuit costs about € 6.15. Parts List      R1 = 10 k      R2 = 330 K?      R3, R6, R13 = 100 k      R4, R8, R11, R14 = 47 Ω      R5, R9, R12 = 1.5 MΩ      R7, R10 = 47 k      P1 = 220 K?      C1, C2, C3 = 100 nF      C4 = 100 uF      D1-D4 = LED      T1, T2, T3 = BC547B      T4 = BC557B      M...

This will flash a LED, employing a single 1.5v cell. it's going to even flash a white LED even supposing this kind of LED needs regarding three.2v to 3.6v for operation. The circuit takes regarding 2mA however produces a really bright flash. LED on 1.5v SUPPLY A red LED needs regarding one.7v before it'll begin to illuminate - below this voltage - NOTHING! This circuit takes regarding 12mA to illuminate a red LED employing a single cell, however the fascinating feature is that the approach the LED is illuminated. The 1u electrolytic may be thought of to be a 1v cell. (If you wish to be technical: it charges to regarding one.5v -0.2v loss as a result of collector-emitter = one.3v and a lost of about 0.2v via collector-emitter in diagram B.) It is firstly charged by the 100R resistor and therefore the third transistor (when it's totally turned ON via the 1k base resistor). this is often shown in diagram "A." throughout this time the second transistor isn't turne...

Rechargeable torches don’t come without problems. You need to replace the bulbs and charge the batteries frequently. The average incandescent light-emitting diode (LED) based torch, for instance, consumes around 2 watts. Here’s a rechargeable white LED-based torch that consumes just 300 mW and has 60 per cent longer service life than an average incandescent torch.  Rechargeable Torch Based on White LED Circuit Diagram Fig. 1 shows the circuit of the rechargeable white LED-based torch. The reactive impedance of capacitors C1 through C3 (rated for 250V AC) limits the current to the charger circuit. The resistor across the capacitors provides a discharge path for the capacitors after the battery is charged. The red LED1 indicates that the circuit is active for charging. The torch uses three NiMH rechargeable button cells, each of 1.2V, 225 mAH. A normal recharge will take at least 12 hours. Each full recharge will give a continuous operational time of approximately 2.5 hours. Recharge...

High efficiency white LEDs have advanced to the point where they can replace glow bulbs and other light sources not only as indicators, but also for illumination. While many of the claims made about the LEDs' efficiency, light quality, lifetime and economy are mostly exaggeration, the truth is that for very low light levels they are now competitive. They have equal or slightly higher efficiency than a flashlight bulb, a longer lifetime, and are very much tougher. On the other hand, they are still far more expensive than a bulb, for a given light output. It follows that LEDs are almost ideal for very tiny, low power flashlights, in the less-than-one-watt category. But such a low power flashlight makes sense only if the whole flashlight is small and lightweight, and has a reasonable battery lifetime. But white LEDs require about 3.3 volts each, and typically some extra voltage is needed to provide room for current regulation! That's why most commercial LED flashlights use at leas...

This is a simple LED as a diode Rectifier Circuit Diagram. In certain situations where the current is not high, we can use the famous LED (LED) and diode rectifier voltage power circuits. The LED can be used without problem in a rectification circuit, and also works in the power ratings. Pay attention not to exceed the maximum current of the LED in a wave rectifier.  Using LED as a diode Rectifier Circuit Diagram

This is a very simple circuit of a dimmer, ie a controller LED brightness, which is powered from the USB port of a PC and a connection is very simple. The resistor R1 sets the maximum current of the LED with the maximum potentiometer, resistor R2 should have a resistance of 10x to 100x greater than R1. The table shows which components to use in accordance with the selected LED. Dimmer-Brightness LED Driver Circuit Diagram

D. Mohan Kumar is famous name in the circuits world. There are d's Power-on Reminder with LED Lamp Circuit Diagram creation. Many a times equipment at workstations remain switched on unnoticed. In this situation, these may get damaged due to overheating. Here is an add-on device for the workbench power supply that reminds you of the power-on status of the connected devices every hour or so by sounding a buzzer for around 20 seconds. It also has a white LED that provides good enough light to locate objects when mains fails. Power-on Reminder with LED Lamp Circuit Diagram    Fig. 1 shows the circuit of power-on reminder with LED lamp. Here, IC NE555  (IC1) is wired as an astable multivibrator, whose time period is set to around six minutes using resistors R1 and R2, preset VR1 and capacitor C1 for sounding the buzzer every hour. The output of IC1 is fed to the clock input of IC CD4017 (IC2). Capacitor C3 and resistor R3 provide power-on-reset pulse to IC2.When power to the ...

This is a LED Multicolour Backlights Circuit Diagram. This circuit comprises two parts: a string of 5mm high-intensity white LEDs connected in series and the circuit wired around. IC CD4060 with an inbuilt oscillator. The IC is wired such that its outputs Q4, Q5 and Q6 are chosen for colour display. On power-’on’ reset, these outputs go ‘high’ simultaneously but for different time durations. The Q4 output goes ‘high’ for about 18 seconds, Q5 about 38 seconds and Q6 about 80 seconds. These outputs are connected to forty 5mm LEDs through transistors T1, T2 and T3. It is necessary to boost the current because LED s are connected in parallel. To do so, transistor BD135 is used. The 1.2-kilo-ohm base resistor prevents overloading of BD135. The 100-ohm resistor acts as the current limiter. Provide heat-sink to each BD135 transistor. LED s of three colours—blue, orange and red—are used here. LED Multicolour Backlights Circuit Diagram   Fig. 1: Circuit for multicolour curtain backlight T...

Strip LEDs are available in different colours powered by direct current (DC) source. These LEDs  are available as surface mount devices with current limiting resistors. Usually there are 300 LEDs in a 5-metre strip. The strip can be cut into pieces so that  the bits having three or four LEDs can  be used with 12V DC source. The circuit given here uses the strip LEDs to  make an automatic white LED lighting  source. Circuit diagram : Simple Strip LED Lamp Circuit Diagram The circuit is powered by a capacitor power supply connected to AC mains. Capacitor C1 drops the 230V  AC, which is further rectified by the bridge rectifier module and is made ripple-free by C2. Zener diode (ZD1) provides 12V DC to the comparator circuit. Resistor R1 is important in the  power supply as it provides discharge path to the voltage stored in capacitor C1 after the circuit is unplugged from  mains. The automatic working of the circuit is based on the light-sensing property of the light-dependent resis...

High efficiency white LEDs have advanced to the point where they can replace glow bulbs and other light sources not only as indicators, but also for illumination. While many of the claims made about the LEDs' efficiency, light quality, lifetime and economy are mostly exaggeration, the truth is that for very low light levels they are now competitive. They have equal or slightly higher efficiency than a flashlight bulb, a longer lifetime, and are very much tougher. On the other hand, they are still far more expensive than a bulb, for a given light output. Cell LED Flashlight Circuit Diagram It follows that LEDs are almost ideal for very tiny, low power flashlights, in the less-than-one-watt category. But such a low power flashlight makes sense only if the whole flashlight is small and lightweight, and has a reasonable battery lifetime. But white LEDs require about 3.3 volts each, and typically some extra voltage is needed to provide room for current regulation! That's why most co...

1.5V POWERED LED FLASHER ELECTRONIC DIAGRAM It is a charge pump design. This is where a capacitor (electrolytic) is allowed to charge and is then raised higher and allowed to discharge into a load. The load sees a voltage that can be higher than the supply.

LED BACKLIGHTING SOLUTION WITH LM3430 and LM3432 ELECTRONIC DIAGRAM The LM3432 is a 6-channel high voltage current regulator which provides a simple solution for LED backlighting applicationsand the LM3430 is a companion device to supply high voltage required to drive serially connected LED strings. The LM3430 and the LM3432 provide a complete solution to most HB-WLED backlighting applications for notebook and PC monitor. In this application note, a typical example for a solution to drive six strings of twelve LEDs in series running at 20mA per string is described in details.

The consumer unit (or ‘electricity meter’) cupboard in some older houses is a badly lit place. If the bell transformer is also located in this cupboard, it may be used to provide emergency lighting by two high-current LEDs. These diodes are powered via a small circuit that switches over to four NiCd batteries when the mains fails. The output voltage of the bell transformer is rectified by bridge B1 and buffered by capacitor C1. The batteries are charged continuously with a current of about 7.5 mA via diode D1 and resistor R2. Circuit diagram: LED Lighting For Consumer Unit Cupboard Circuit Diagram The base of transistor T1 is high via R3, so that the transistor is cut off. When the mains voltage fails, C1 is discharged via R1; when the potential across it has dropped to a given value, the battery voltage switches on T1 via R3 and R1, provided switch S1 is closed. When T1 is on, a current of some 20 mA flows through diodes D4 and D5. The light from these LEDs is sufficient to enabl...

This is the simple project of LED Matrix Horizontally The circuit in this Design Idea shows an unconventional way to use a 5×7 LED matrix.You can use a design containing a set of 5×7 LED units without changing anything in the circuitry, except for the arrangement of the LED units.   Using one 5×7 LED matrix, or N units, horizontally instead of vertically allows the display of two characters, or 2×N characters. The minimum pattern for lowercase and uppercase letters requires only a 3×5 LED configuration, except for the letters M and m, which require at least a 5×5 LED configuration and need a dedicated subroutine. The circuit in Figure 1 uses an 8-bit, 18-pin PIC microcontroller and a decade counter to drive one or two 5×7 LED units to provide a display module of two or four digits. The circuit uses a small pushbutton switch to increment the counter. By default, the circuit works in high-brightness mode. If you press the pushbutton during power-on, the circuit works in ...

A very simple 6 channel low cost led driver electronic circuit project can be designed using the MCP34845 LED drivers manufactured by Free scale Semiconductor.The MCP34845 LED drivers operates from 5 to 21 volts and is specially designed for use in back lighting LCD displays from 10" to 17"+ for devices like : PC Notebooks , Net books , Picture Frames , Portable DVD Players , Small Screen Televisions , Industrial Displays , Medical Displays , etc. 6 Channel LED Driver Circuit Diagram The MCP34845 LED drivers is capable of driving up to 16 LEDs in series in 6 separate strings.PWM dimming is performed by applying a PWM input signal to the PWM pin which modulates the LED channels directly.Main features of this driver circuit project are : input voltage of 5.0 to 21 V , boost output voltage up to 60 V, 2.0 A integrated boost FET , fixed boost frequency - 600 kHz or 1.2 MHz , OTP, OCP, UVLO fault detection , LED short/open protection , programmable LED current between 3.0 mA and 3...

This is the simple version of a white LED lamp that can be directly powered from mains. It can give ample light even for reading purpose. Capacitor CX along with diodes D1 through D4 forms the AC step down circuit. CX reduces high voltage AC from mains to a low voltage AC which is rectified by the diodes D1-D4. 220V AC Powered White Led Lamp Circuit Diagram Capacitor C1 removes ripples from AC so that low voltage DC is available to power the LEDs.CX is the X rated AC capacitor that reduces AC voltage through capacitive rectance property. Resistor R1 is very important to remove the stored voltage from CX when power is switched off. This prevents lethal shock. Resistor R2 limits the inrush current. More LEDs can be added by reducing the value of R2.Since the circuit is directly connected to mains, take utmost care to avoid shock. No components should be touched when it is connected to mains.

The bi-directional sequencer uses a 4 bit binary up/down counter (CD4516) and two "1 of 8 line decoders" (74HC138 or 74HCT138) to generate the popular "Night Rider" display. A Schmitt Trigger oscillator provides the clock signal for the counter and the rate can be adjusted with the 500K pot. Two additional Schmitt Trigger inverters are used as a SET/RESET latch to control the counting direction (up or down). Be sure to use the 74HC14 and not the 74HCT14, the 74HCT14 may not work due to the low TTL input trigger level. When the highest count is reached (1111) the low output at pin 7 sets the latch so that the UP/DOWN input to the counter goes low and causes the counter to begin decrementing.  When the lowest count is reached (0000) the latch is reset (high) so that the counter will begin incrementing on the next rising clock edge. The three lowest counter bits (Q0, Q1, Q2) are connected to both decoders in parallel and the highest bit Q3 is used to select the appropr...