Rongge

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 certainly a low-cost 20W/40W fluorescent lamp inverter circuit project. Even so the maximum effective would be to make use of a 40 watt tube (or two 20 watt tubes in series). It is a circuit you may put collectively from junk box parts or assemble from a kit. It certainly is quite easy to construct and no need printed circuit board. The transformer is hand-wound on a ferrite rod (from an old transistor radio) and the winding wire could be salvaged from an old transformer. We’re intentionally maintaining bills down to confirm how cheaply it could be put together. 20W/40W Fluorescent Lamp Inverter Schematic Dependant upon your stock of components, the cost could vary from $3.00 to about $15.00 and in case the wires from the transformer are soldered to the ends of the tube(s), you are able to make a free-standing light that can be set-up in the garden to light up a dark place without having the worry of operating 240v wiring. The cost of powering the circuit is about 22 watts and ...

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 ...

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...

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.

Description 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: When you connect wrong polarity, the fuse will blow up. For charging a lea...

The PR4403 is an enhanced cousin of the PR4402 40 mA 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 thresh-old value the PR4403 switches on. During  the day the battery is charged and, with  the LED off, the driver only draws 100 µA. Circuit Diagram : Solar Lamp using the 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 pack-age with a lead pitch of 1.27 mm. The  other components are a 1N...

Compact circuit, Can be wired in parallel to existing switches This device allows one or more lamps to illuminate at sunset and turn off at dawn.Q1 and Q2 form a trigger device for the SCR, providing short pulses at 100Hz frequency. Pulse duration is set by R2 and C1.When the light hits R1, the photo resistor assumes a very low resistance value, almost shorting C1 and preventing circuit operation. When R1 is in the dark, its resistance value becomes very high thus enabling circuit operation.   Circuit Diagram: Dark Activated 220 volt AC Lamp Circuit Diagram Parts: R1 = LDR R2 = 100K R3 = 200K R4 = 470R R5 = 12KR6 = 1KR7 = 470R C1 = 10nF-63V D1 = TIC106D D2 = 1N4007D3 = 1N4007D4 = 1N4007 D5 = 1N4007 Q1 = BD327 Q2 = BD337 SK1 = Female Mains Socket   Notes: R3 allows fine setting of operating threshold and R2 value can be raised to 150K maximum. Several lamps wired in parallel can be connected to the circuit, provided total power dissipation of the load does not exceed about 300...