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This flashing lights circuit can be used as beacon. The assembly consists basically of two blinking steps that commands two light bulbs. With the help of P1 you can adjust the flashing frequency between some limits. Circuit diagram : Flashing Lamp Lights Circuit Diagram There are 2 parts for the circuit, the second one works the same way as the other but with the help of a wire bridge or a switch you can choose different operating modes. A bridge between M and 3 means: 2 independent blinks. If there is a bridge between M and 2, then the lamps lights alternatively with a frequency that can be adjusted with P1. And finally there is one more possibility for M and 1, where the lamps blinks at the same time. The flashing lights circuit works with voltages between 3V and 15V.  The lamps voltage must be 2/3 of working voltage. R5 and R10 are chosen so that the lamps are about to light.

Why a lamp tester or fuse tester? Testing cables, wires, lamps… belongs to a repair job and sometimes this becomes too cumbersome since one has only two hands and too often, one has to hold the part being tester and the two probes of an ordinary continuity tester all at the same time. This fuse and lamp tester enables easy testing of lamps and fuses by using the conductivity of the human body. One of the test probes is connected to the part under test while the other probe is hel dby the normal hand. When the lamp or fuse is working properly, your eyes will glow in the dark! Just kidding :) . When the lamp or fuse is working properly, a small amount of current flows through the hand which is enough to switch the transistors and light the LED.

You can save on your electricity bills by switching to alternative sources of power. The photovoltaic module or solar panel described here is capable of delivering a power of 5 watts. At full sunlight, the solar panel outputs 16.5V. It can deliver a current of 300-350 mA. Using it you can charge three types of batteries: lead acid, Ni-Cd and Li-ion. The lead-acid batteries are commonly used in emergency lamps and UPS. The working of the circuit is simple. The output of the solar panel is fed via diode 1N5402 (D1), which acts as a polarity guard and protects the solar panel. An ammeter is connected in series between diode D1 and fuse to measure the current flowing during charging of the batteries. As shown in Fig. 1, we have used an analogue multimeter in 500mA range. Diode D2 is used for protection against reverse polarity in case of wrong connection of the lead-acid battery. Charger circuit diagram: Solar Panel Based Charger Circuit Diagram When you connect wrong polarity, the fuse ...

Description  In most countries it is now mandatory or at least recommended to have a rear fog light on a trailer with the additional requirement that, when the trailer is coupled to the car, the rear fog light of the towing car has to be off. The circuit shown here is eminently suitable for this application. The circuit is placed near the rear fog light of the car. The 12-V connection to the lamp has to be interrupted and is instead connected to relay contacts 30 and 87A (K1, K3). When the rear fog light is turned on it will continue to operate normally. Circuit Diagram:   If a trailer with fog light is now connected to the trailer connector (7- or 13-way, K2), a current will flow through L1. L1 is a coil with about 8 turns, wound around reed contact S1. S1 will close because of the current through L1, which in turn energizes relay Re1 and the rear fog light of the car is switched off. The fog light of the trailer is on, obviously. The size of L1 depends on reed contact S1. Th...

Nowadays you can buy white LEDs, which emit quite a bit of light. They are so bright that you shouldn’t look directly at them. They are still expensive, but that is bound to change. You can make a very good solid-state pocket torch using a few of these white LEDs.  Dimmable White LED Lamp  Circuit Diagram  The 12V DC input voltage is routed through the 1A fuse and the on/off switch. The 1N4001 diode acts as a crowbar device. If reverse polarity is applied, the fuse will blow and the rest of the circuitry will be protected. Power is sent to the LM2941CT voltage regulator IC. The regulator is wired to produce a voltage range from 5.5V (dim) to 8.3V (bright).  The 4.7K resistor across the 1K brightness adjustment potentiometer produces a non-linear brightness adjustment to compensate for the eye's logarithmic brightness perception response. The LEDs are organized in six series groups of three with a 24 ohm current limiting resistor on each group. This arrangement limits...

This circuit was designed to provide that continuous light lamps already wired into a circuit, become flashing. Simply insert the circuit between existing lamp and negative supply. Especially suited for car or panel pilot lights, this device can drive lamps up to 10W. Circuit diagram : Two-wire Lamp Flasher Circuit Diagram Parts: R1_____6K8  1/4W Resistor R2_____270K   1/4W Resistor R3_____22K   1/4W Resistor C1_____220µF   25V Electrolytic Capacitor C2_____10µF   25V Electrolytic Capacitor D1_____1N4002  100V 1A Diode Q1_____BC557   45V 100mA PNP Transistor Q2_____BD139   80V 1.5A NPN Transistor LP1_____Existing filament Lamp: any type in the range 3-24V 10W max. SW1_____Existing On-Off switch B1_____Existing V DC source: any type in the range 3-24V suited to the lamp adopted Notes: Break lamp(s) to negative supply connection(s), then insert the circuit between existing lamp(s) connection(s) and negative supply (respecting polarities!). C1 value can be varied from 100 to 1000µF ...

This project involves constructing an energy efficient dual 3 Watt white LED array that runs on 12VDC at 700mA. The lamp is useful for indoor indirect room lighting. The light that is produced does not flicker and has a regulated brightness from 11V to the maximum operating voltage. The Avago 3W white LEDs are rated at 3 watts (nominal). Never stare directly at this lamp when it is running at full operating power, it is dangerously bright. Specifications: Nominal operating voltage: 12V DC Nominal operating current: 700 mA Maximum operating voltage: 16V DC Power consumption at 12.0V: 8.4W Minimum voltage for regulated light: 11V DC Leds produce light down to: 6V DC White LED voltage: 3.7V DC each White LED input power: 2.59 W each Voltage across regulator when current becomes regulated: 3.3V DC Theory: The lamp is wired as a current loop which includes the power supply, the LED series string and the 700 mA current regulator circuit. The LM317 and 1.8 ohm 5 Watt resistor act as a current...

Sometimes we forget to switch off the bathroom light and it remains on unnoticed for long periods. This circuit solves the problem of electricity wastage by switching off the lamp automatically after 30 minutes once it is switched on. The back-up LED lamp provided in the circuit turns on for three minutes when mains fails. This is helpful especially when you are taking a shower at night. The circuit is built around binary counter CD4060 (IC2), which has a built-in oscillator and 14 cascaded bistable multivibrators. The oscillator generates clock pulses based on the values of resistors R3 and R4 and capacitor C3. Automatic Bathroom Light with Back-up Lamp Circuit Diagram   For the given values, Q11 output of IC2 goes high after 30 minutes of power-on. Resistor R2 resets the IC for proper operation. The output of IC2 is fed to the gate of the SCR via resistor R6 and LED2, which function as a voltage dropper as well as output status indicator. When the SCR gets gate drive, it fires to...

Varying Brightness AC Lamp Circuit , an SCR is used to slowly vary the intensity of a 120 volt light bulb by controlling the time that the AC line voltage is applied to the lamp during each half cycle. Varying Brightness AC Lamp Circuit Diagram Caution: The circuit is directly connected to the AC power line and should be placed inside an enclosure that will prevent direct contact with any of the components. To avoid electrical shock, do not touch any part of the circuit while it is connected to the AC power line. A 2K, 10 watt power resistor is used to drop the line voltage down to 9 volts DC. This resistor will dissipate about 7 watts and needs some ventilation. Operation: A couple NPN transistors are used to detect the beginning of each half cycle and trigger a delay timer which in turn triggers the SCR at the end of the delay time. The delay time is established by a current source which is controlled by a 4017 decade counter. The first count (pin 3) sets the current to a minimum whi...

Description  General Description of the following circuit. 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 flashing function controlled by one option pin.It only requires one external resistor for typical application. It is very suitable for the use of the flash products such as disco glasses, disco hat, gift card, X’mas decoration and so forth. author : Izhar Fareed - izha@rgmx.us  source - extremecircuits.net

This small and bright LED lamp is telephone line powered, means it uses the power of our telephone line. There are about -40v to -50v at telephone line, LM317T is used to adjust them according to our demand. 12 white LEDs of 5mm dia is used in this lamp, are all in series to compensate the voltage. Out of four wires of telephone only red and green is of our interest. This telephone line powered LED lamp is small, efficient and bright; one can also be use this for study or desk lamp. Schematic: Telephone Line Operated LED Lamp Components Required: BR2----------------------Bridge Rectifire U2------------------------LM617T or LM317L R3-------------------------270 ohm 1/2watt R4-------------------------6.8k ohm 12 white LEDs

The PR4403 is an enhanced cousin of the PR4402 40mA LED driver. It has an extra input called LS which can be taken low to turn the LED on. This makes it very easy to build an automatic LED lamp using a rechargeable battery and a solar module. The LS input is connected directly to the solar cell, which allows the module to be used as a light sensor at the same time as it charges the battery via a diode. When darkness falls so does the voltage across the solar module: when it is below a threshold value the PR4403 switches on. During the day the battery is charged and, with the LED of, the driver only draws 100µA. Circuit diagram: Solar Lamp Using PR4403 Circuit Diagram At night the energy stored in the battery is released into the LED. In contrast to similar designs, here we can make do with a single 1.2 V cell. The PR4403 is available in an SO-8 package with a lead pitch of 1.27 mm. The other components are a 1N4148 diode (or a Schottky 1N5819) and a 4.7µH choke. Pin 2 is the LS enable ...

Ultra-low current drawing 1.5V battery supply 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. An optional Photo resistor will switch-off the circuit in daylight or when room lamps illuminate, allowing further current economy. This device will run for about 3 months continuously on an ordinary AA sized cell or for around 6 months on an alkaline type cell but, adding the Photo resistor circuitry, running time will be doubled or, very likely, triplicated. Battery Powered Night Lamp Circuit Diagram Parts: R1,R2___________1M 1/4W Resistors R3_____________47K 1/4W Resistor (optional: see Notes) R4____________Photo resistor (any type, optional: see Notes) C1____________100nF 63V Polyester Capacitor C2____________220µF 25V Electrolytic Capac...

I got myself some UV-curable solder mask for my PCB workshop, and as soon as i got it, i discovered that my UV artwork transfer box is totally incapable to activate the UV paint and cure it. I began searching the net for powerful UV lamps, and then it hit me: Some months ago i uploaded a theory regarding the Cold and Hot cathode discharge lamps. During my research for these lamps i found out that they can provide directly visible light (lamps without internal coating), or they produce UV radiation. The lamps that produce UV radiation have an extra coating on their internal surface which glows when excited by the UV rays, thus producing light! [ ]

They are so bright that you shouldn’t look directly at them. They are still expensive, but that is bound to change. You can make a very good solid-state pocket torch using a few of these white LEDs. Dimmable White LED Lamp Circuit Diagram The 12V DC input voltage is routed through the 1A fuse and the on/off switch. The 1N4001 diode acts as a crowbar device. If reverse polarity is applied, the fuse will blow and the rest of the circuitry will be protected. Power is sent to the LM2941CT voltage regulator IC. The regulator is wired to produce a voltage range from 5.5V (dim) to 8.3V (bright).  The 4.7K resistor across the 1K brightness adjustment potentiometer produces a non-linear brightness adjustment to compensate for the eye's logarithmic brightness perception response. The LEDs are organized in six series groups of three with a 24 ohm current limiting resistor on each group. This arrangement limits the maximum current through each LED group to around 20mA. Connect the DC input ter...