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Showing posts with label led. Show all posts
Showing posts with label led. Show all posts

Sunday, September 21, 2014

Current Controlled Boost LED Driver and Black Soldermasks

The MAX16834 is a neat little chip (its not the only one, there are plenty of others out there) that allows high efficiency designs for LED string driving. It provides a platform for a Buck or Boost converter design, as well as brightness adjustment via analog/PWM input pins, as well as a fault output (in case of open/short circuits for example) and also diverse other functionalities that can be quite useful. [Link]


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Wednesday, June 12, 2013

Camera LED Flashlight Can Be Considered a Security Products

Overview:
Multifunctional patrol led flashlights are suitable to power, oil, machinery, petrochemical, gas maintenance, military, police, mining enterprises and other workplaces, it is efficient and practical as security, patrol, inspection equipment. This camera flashlight aslo can be a security products, it is very helpful to go outdoor.


Features:
● Multifunctional patrol led flashlight with lighting, video, camera, sound recording function.

● 4G high-capacity memory, support for all-weather high-definition camera, convenient USB interface with computer communications to facilitate the uploading and downloading data.

● Light using three imported high brightness white LED lamp, 3 kinds of light regulation mode, the service life of up to 100,000 hours. Reflector with high-tech surface treatment - orange peel aluminum reflector cup, reflective, high efficiency, tempered glass lens, the distance of light up to 200 meters.

● 2 Lithium-batteries, large capacity, long life, low self-discharge, the economic environment.

● Early use flashlight, the outer surface has three buttons, they are namely, key lighting, DV keys and camera key, key is also the DV Power key: Press the power on or off 3S, DV open and close.

● High hardness and magnesium alloy casing, to ensure that its able to withstand strong impact; Rain-proof and high temperature resistance, humidity resistance, and can be used in a variety of harsh environmental conditions.

● Outer surface is army gray, light oxidation, deep non-slip handle, light and beautiful and easily to carry.
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Cons of the LED light bulb

We moved to the country yard to live with our parents last month. They found that the house need more bright especially in the rainy winter morning & evening. They planed to buy some bulbs to make our house much brighter. Some one stated to buy some incandescent bulbs. Some suggested buying some CFL (Compact Fluorescent Lamp). But I insisted on buying some LED (Light-Emitting Diodes). An argument was burst in our large relatives.

My brother stated that incandescent is the lowest priced one. & they had use incandescent for so lots of years. It is  nice. & the yellow light is much brighter in the foggy days. The most important thing was that they was used to living in the yellow light. & they felt warm in the yellow light.

I prepared the some useful information to persuade them to pick the LED light bulb. There are the professionals & cons of the LED light bulb.

My husband stated that efficient CFL is the best choice since it is not as pricey. It is brighter than the incandescent bulbs. & it saves more energy. There is no doubt that an LED equivalent light bulb (for example a 6w LED spotlight as a direct replacement for a 35w GU10 halogen lamp) is significantly more pricey than either the original or a CFL alternative. & the cost of LED light bulb ranges $20-$120, depending on the company & product.

It is brighter than that of CFL or incandescent bulb. It emits light of an intended color without the use of color filters. It lights up very quickly. Unlike the CFL which need one or six seconds to light up. LED bulbs generate little heat, which mean it stay cooler than other light bulbs.

Pros of LED Light Bulb

It contains no mercury, unlike CFL. There is no UV, infrared or other deleterious output. For the equivalent of a 60 watt bulb, LED makes use of an average of 5-7 watts compared to 13-15 watts CFL, & 60 watts incandescent.

It lasts up to 10 times longer than some advertise 60,000 hours. It lasts 35,000 to 50, 000 hours of useful life. Cent tubes are usually are rated at about 10,000 to 15,000 hours. Depending partly on the conditions of use, incandescent light bulb lasts about 1,000 to 2,000 hours. Because of its long life span, LED is used on trucks tail lights, & other lighting for safety proposes.

Cons of LED Light Bulb

LED are more long lasting than incandescent or fluorescent lighting. The LED light bulb features excellent shock resistance. It is hard to damage during the delivery.

    LED light bulb is not cheap. It is economical to buy LED bulbs even if other light bulbs are free. If a LED bulb cost $50 dollars. It is still cheap to buy the $50 dollars LED bulb because LED will save you more money on your utility cost over the long haul. But I found some LED light bulbs here are  cheaper than you thought.
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Friday, May 17, 2013

40 Segment LED S Meter

40 Segment LED S-Meter40 Segment LED S-Meter Circuit

Provide your radio with a actual cord signal, again acclimatize the HIGH LEVEL pot to the beginning of anecdotic the aftermost LED (all LEDs on). Remove the arresting completely, again acclimatize the LOW LEVEL pot to the beginning of no LEDs illuminated.

If your radios S-meter achievement is greater than 5 volts, you mau ambition to alter the HIGH LEVEL pot with a 10K resistor, and accommodate pin 6 of the right-most 3914 with the cathode of a 6.1 volt zener diode, pulled up to 13 volts with a 1K resistor. The anode should be affiliated to ground. You may use a college voltage zener if necessary.

This agreement provides 10ma per LED segment. Change the ethics to the resistors and pots to change the drive accepted to the LEDs. R1=12.5/I R2=25/I R3=37.5/I R4=50/I area I = the adapted LED current

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Tuesday, May 14, 2013

LED Pulsere circuit for the Christmas Star

This circuit can be used to decorate your Christmas star.Here the LED light up gradually and disappear gradually.you can attach 6 LEDs for this.Supply 4.5v - 6v for this circuit.Here we have used femous IC LM358 .So you all will be able to find that IC easily.

Parts
IC1__________LM358 Low Power Dual Op-amp
Q1___________BC337 45V 800mA NPN Transistor
R1,R2___________4K7 1/4W Resistors
R3_____________22K 1/4W Resistor
R4______________2M2 1/4W Resistor
R5_____________10K 1/4W Resistor
R6_____________47R 1/4W Resistor
C1______________1µF 63V Polyester Capacitor
D1_____________5mm. Red LED
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Thursday, April 11, 2013

SP LED Flashlight Using Supercapacitor

Bored of joking with capacitors? Then its time for you to maneuver on to super-capacitors. These have huge storage capabilities. during this article you may conclude the way to build atiny low LED flashlight using supercapacitors.

The most disadvantage of capacitors is their giant voltage drop. For this project, a minimum voltage of two volts is needed to light-weight the LED. As a result, the “Joule Thief” style would be incorporated here. Using this, a AA battery is used to light-weight an LED until its fully discharged.
 during this case, a supercapacitor would be taking the place of the battery. Here an LED is employed to perform the operate of a diode. This ensures that theres sufficient voltage across the LED.

 the necessities of the project are listed below:
White LED
Super capacitor (10F, 2.7 V)
Transistor
Torus
1 k ohm resistor
Wires
Breadboard
The torus and therefore the transistor used here comes from an energy-saving lamp HS. Care ought to be taken whereas removing this from the lamp as a breakage may lead to the discharge of the mercury vapors. A lamp load along side a USB port is added to the circuit. This makes it compatible with a computer or a automotive radio.


A couple of precautions got to be taken whereas constructing the circuit. The USB port mustnt be supplied with excess power. The capacitor doesnt stand up to a high voltage and hence a zener diode is connected in parallel to handle the high voltage. The diode protects the capacitor when the voltage exceeds an explicit price.
 
 
 
http://streampowers.blogspot.com/2012/07/sp-led-flashlight-using-supercapacitor.html 
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Wednesday, April 10, 2013

Simple Strip LED Lamp

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.

Simple Strip LED Lamp 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 resistor (LDR). Operational amplifier CA3140 (IC1) is used as a comparator with two potential dividers in its inverting and non-inverting inputs. LDR1 and  resistor R3 form one potential divider  that provides a variable voltage at the  inverting input pin 2 of IC1. Second  potential divider comprises resistors  R4 and R5, which provide half of the  supply voltage (6V) to the non-inverting pin 3 of IC1. The output of IC1 depends on voltage level at inverting  input pin 2 of IC1 as explained below.

In daylight, LDR1 has low resistance and the voltage at inverting input (pin 2) of IC1 is more than that of non-inverting input (pin 3). This makes IC1 output low, which drives transistor T1 into cut-off condition and strip LEDs do not glow. However, at night the light incident on LDR1 is low and its resistance is high. The voltage at inverting input of the comparator decreases, making it lower than the voltage at non-inverting input. This makes IC1 output high. Transistor T1 goes into saturation,  thus connecting cathodes of LEDs to  ground. All the LEDs in the strip turn  on and remain that way till morning.

Assemble the circuit on a general-purpose PCB and enclose it in a suit-able shock-proof case. Strip LEDs are available in ribbon-shaped form. Use 5cm bits (two bits) having three  LEDs each. The strip can be cut at supply-contact points. Strip LEDs are arranged on a flexible belt with  double-sided adhesive on the back  side, so it can be glued to any surface.  Connect the LED strip in the circuit  with correct polarity.
EFY note. Since the circuit uses 230V AC, there is a risk of electrical shock. Do not touch or troubleshoot when the circuit is plugged in.Before connecting the circuit to the power supply section, test it using 12V DC from a battery or DC power supply.


Source:  http://www.ecircuitslab.com/2012/05/simple-strip-led-lamp.html
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Monday, April 8, 2013

Simple Solar LED Lantern

This solar LED lantern can be used as an emergency light. Its 6V battery can be charged either from 230V, 50Hz AC mains or a 12V, 10W solar panel. Two LED indicators have been provided—red LED (LED1) indicates battery charging and green LED (LED2) indicates fully-charged battery.

You can choose to charge the battery either from the mains power or the solar panel by using the single-pole, double-throw (SPDT) switch. Capacitor C1 (1000µF, 35V) removes ripples from the power supply and regulator IC LM7809 (IC1) provides regulated 9V DC to the emitter of pnp transistor T1 (TIP127/BD140) and pin 7 of op-amp IC CA3140 (IC2), which is configured in comparator mode.
Solar LED Lantern
The reference voltage of 6.3V at pin 2 of IC2 is obtained through the combination of resistor R7 (1-kilo-ohm) and zener diode ZD1 (6.3V). The comparator controls charging of the battery. Pin 3 of IC2 is connected to the positive terminal of the battery to be charged through resistor R5. When the battery is fully charged, it stops charging and the green LED (LED2) glows to indicate the full-charge status.

When the battery voltage is low, diode D1 (1N4007) forward-biases and the battery connects (through resistor R3) to the collector of T1 for charging (indicated by the glowing of red LED1). Three high-wattage white LEDs (LED3 through LED5), such as KLHP3433 from Kwality Photonics, are used for lighting. These are switched on using switch S3.
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Friday, April 5, 2013

LED Power Meter

LED power Meter circuit is a simple RF detector using diodes to charge a capacitor. The voltage developed across the capacitor is indicated by a multimeter set to a low voltage range. The circuit is soldered together without the need for a PC board, as can be seen in the diagram below and paper clips are used for the positive and negative terminals of the multimeter.
LED Power Meter circuit

The level power output of an FM transmitter is indicated by the illumination of a LED and the voltage reading on the multimeter gives a further indication of the output.

A digital multimeter may be used but the presence of RF may produce a false reading. Likewise, the radiated energy may upset some analogue meters and you may get full scale deflection on the 15v range as well as the 250v range! But the LED wont lie. It will accurately indicate the RF and you can see the change in brightness as you adjust the coils in the output stage. Some of the cheapest and simplest multimeters will give the best results as they have a low sensitivity and the radiated RF energy will not induce a reading. Even a damaged multimeter can be used, provided the 10v or 15v DC scale is operating.

The reading is not calibrated and does not represent milliwatts output. It is only a visual indication. 
We have designed over 10 FM transmitters for inclusion in the pages of this e-magazine and each one has different features and characteristics. Some are designed for 3v operation, some are for 9v operation, some are stable for hand-held situations and others are designed for high output. The illumination of the LED will range from barely visible to very bright. 

LED Power Meter Parts 
1 - 470R
1 - 100p ceramic
1 - 100n ceramic
2 - 1N 4148 diodes
1 - 5mm Red LED
1 - 2in (5cm) hook-up wire
2 - paper clips
No PC board required
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