Posts

Showing posts with the label lamp

12V Flourescent Lamp Inverter

Image
12V Fluorescent Lamp Inverter Circuit Diagram. Fluorescent tubes use far less energy than incandescent lamps and fluorescent tubes last a great deal longer as well. Other advantages are diffuse, glare-free lighting and low heat output. For these reasons, fluorescent lighting is the natural choice in commercial and retail buildings, workshops and factories. For battery-powered lighting, fluorescent lights are also the first choice because of their high efficiency. The main drawback with running fluorescent lights from battery power is that an inverter is required to drive the tubes. 12V Fluorescent Lamp Inverter Circuit Diagram 12V Fluorescent Lamp Inverter Circuit Diagram . Fig.1: two switch-mode circuits are involved here: the DC-DC inverter involving IC1, Q1 & Q2 and the fluoro tube driver which converts high voltage DC to AC via IC3 and Q3 & Q4 in a totem-pole circuit. Inverter efficiency then becomes the major issue. There are many commercial 12V-operated fluorescent lamps...

Automotive Turn Flasher with lamp output Detection

Image
Here is a circuit of a flasher which I designed for automotive use. It has a built-in function of lamp-outage detection. In normal operation, it will flash at about 1.4Hz and when a lamp goes bad, the flash-rate is doubled. The flashers faster clicking sound and the dashboard indicators faster flashing attracts the drivers attention that one of the bulbs has gone out.  Automotive Turn Flasher with lamp  output Detection Notes The circuit consists of two parts - the flashing unit and the lamp outage detection module. The flashing unit is built around 555 timer configured as an astable multivibrator. The resistors R12/R13 and capacitors C3/C4 sets the required frequency. Note that C3 is connected in parallel to C4 through BC547 an NPN transistor, acting as a switch. When there is positive voltage at the base of the transistor, it conducts and connects C3 to ground. C3 & C4 in parallel doubles the capacitance value i.e. 220nF + 220nF = 440nF. This capacitance value together w...

A Bedside Lamp Timer Circuit Schematic

Image
30 minutes operation, Blinking LED signals 6 last minutes before turn-off The purpose of this circuit is to power a lamp or other appliance for a given time (30 minutes in this case), and then to turn it off. It is useful when reading at bed by night, turning off the bedside lamp automatically in case the reader falls asleep... After turn-on by P1 pushbutton, the LED illuminates for around 25 minutes, but then it starts to blink for two minutes, stops blinking for two minutes and blinks for another two just before switching the lamp off, thus signaling that the on-time is ending. If the user want to prolong the reading, he/she can earn another half-hour of light by pushing on P1. Turning-off the lamp at user's ease is obtained by pushing on P2. Circuit diagram: A Bedside Lamp Timer Circuit Diagram Parts: Resistors R1 = 1K R2 = 4K7 R3 = 10M R4 = 1M R5 = 10K Capacitors C1 = 470µF-25V C2-C4100nF-63V Semiconductors C1 = 470µF-25V C2-C4 = 100nF-63V D1-D4 = 1N4002 D5 = 5mm. Red LED IC1 =...

Ultra Bright LED Lamp Circuit Diagram

Image
This is a simple project of Ultra-Bright LED Lamp Circuit Diagram. This ultra-bright white LED lamp works on 230V AC with minimal power consumption. It can be used to illuminate VU meters, SWR meters, etc. Ultra-bright LEDs available in the market cost Rs 8 to 15.These LEDs emit a 1000-6000mCd bright white light like welding arc and work on 3 volts, 10 mA. Their maximum voltage is 3.6 volts and the current is 25 mA. Anti-static precautions should be taken when handling the LEDs. Ultra-Bright LED Lamp Circuit Diagram Fig.1: Ultra-Bright LED Lamp Circuit Diagram The LEDs in water-clear plastic package emit spotlight, while diffused type LEDs have a wide-angle radiation pattern. This circuit (Fig. 1) employs capacitive reactance for limiting the current flow through the LEDs on application of mains voltage to the circuit. If we use only a series resistor for limiting the current with mains operation, the limiting resistor itself will dissipate around 2 to 3 watts of power,whereas no powe...