Showing posts with label flasher. Show all posts
Showing posts with label flasher. Show all posts
Thursday, October 23, 2014
LED Flasher Circuit Using 555 Timer IC
This is a simple LED flasher project that uses a common 555 timer IC for its operation. It is configured as an astable mode which means that its output is a square wave oscillator. Two LEDs are connected to its output in such a way that when one LED is ON, the other LED will turn OFF.
It uses only 10 simple parts that are easily available at any electronic shops. Capacitor C2 charges exponentially through resistors R1, R2 and the resistance of the trimpot. When C2 has charged to about 2/3 VCC it stops charging and it discharges to about 1/3 VCC through R2 and the trimpot resistance via pin 7. This is the standard operation of a 555 timer. When a Vcc of 5 V to 15 V DC is applied to the circuit, the LED will start to flash.
The frequency of the flashing can be changed by varying the resistance of the potentiometer or trimpot. Parts List The parts list of the simple LED project is as shown below.
Friday, September 19, 2014
3v Low Battery Voltage Flasher
Many battery powered devices use two AA alkaline cells. Often you will not know when it is time to replace the batteries until the device powered by them actually stops operating. The hobby circuit below can be connected to a 3v battery, to give you some warning when the battery is nearing its end of life.
It will flash a LED when the battery voltage drops to about 2.4 volts. The electronic circuit draws only 1ua of current in standby mode and jumps to only 20ua when flashing, so it can safely be included without depleting the battery energy. A voltage detector IC from Panasonic (Microchip also makes similar devices) is used to monitor the battery voltage. The device’s open drain output swings low, when the battery voltage is below 2.4 to 2.5 volts. This action turns on the two transistor oscillator circuit, which drives the LED with short current pulses lasting only 2ms.
Source: DiscoverCircuits
Thursday, September 11, 2014
Light Flasher
This is a very basic schema for flashing one or more LEDS and also to alternately flash one or more LEDs.It uses a 555 timer setup as an astable multivibrator with a variable frequency.
With the preset at its max. the flashing rate of the LED is about 1/2 a second. It can be increased by increasing the value of the capacitor from 10uF to a higher value. For example if it is increased to 22uF the flashing rate becomes 1 second.
There is also provision to convert it into an alternating flasher. You just have to connect a LED and a 330ohm as shown in Fig.2 to the points X and Y of Fig.1. Then both the LEDs flash alternately.
Since the 555 can supply or sink in upto 200mA of current, you can connect upto about 18 LEDS in parallel both for the flasher and alternating flasher (that makes a total of 36 LEDs for alternating flasher).
Monday, September 1, 2014
Build a 3 Channels LED Flasher Wiring diagram Schematic
Build a 3 Channels LED Flasher Circuit Diagram. Inserting two 1-MO resistors, R1 and R2, in the output stage of one of the schema`s inverters limits the current needed by the oscillator tone more than a few pA. This schema includes a CD4007 package, which has three CMOS inverters. It forms a standard three-inverter oscillator. Resistors R1 and R2, in series with separate drains on inverter pins 8 and 13, limit the oscillator`s supply current. Capacitor C1 and resistors R5 set the off time of the oscillator, C1; R6 sets the on time.
Three Years LED Flasher Circuit Diagram
A VN10KM small-power FET, current limited by R4, drives two HLMP-3300 LEDs. The LEDs consume about 20 mA for 1 ms. Their average current determines battery life. Since the LEDs in the schema flash at 1 Hz, the average current drain is about 1/1000 of 20 mA, or 20 p.A. A 9-V battery should last about three years at the current drain-essentially the shelf life of an alkaline battery.
Thursday, August 28, 2014
LED Flasher Circuit Using 555 Timer IC
This is a simple LED flasher project that uses a common 555 timer IC for its operation. It is configured as an astable mode which means that its output is a square wave oscillator. Two LEDs are connected to its output in such a way that when one LED is ON, the other LED will turn OFF.
It uses only 10 simple parts that are easily available at any electronic shops. Capacitor C2 charges exponentially through resistors R1, R2 and the resistance of the trimpot. When C2 has charged to about 2/3 VCC it stops charging and it discharges to about 1/3 VCC through R2 and the trimpot resistance via pin 7. This is the standard operation of a 555 timer. When a Vcc of 5 V to 15 V DC is applied to the circuit, the LED will start to flash.
The frequency of the flashing can be changed by varying the resistance of the potentiometer or trimpot.Parts List The parts list of the simple LED project is as shown below.
Wednesday, August 27, 2014
Car Bulb Flasher
This astonishingly simple schema allows one or two powerful 12V 21W car bulbs to be driven in flashing mode by means of a power MosFet. Devices of this kind are particularly suited for road, traffic and yard alerts and in all cases where mains supply are not available but a powerful flashing light are yet necessary.
Parts:
R1 = 6.8K
R2 = 220K
R3 = 22K
C1 = 100uF-25V
C2 = 10u-25V
D1 = 1N4002
Q1 = BC557
Q2 = IRF530
LP1 = 12V-21W Car Filament Bulb (See Notes)
SW1 = SPST Switch (3 Amp minimum)
Notes:
* Flashing frequency can be varied within a limited range by changing C1 value.
* As high dc currents are involved, please use suitably sized cables for battery and bulb(s) connections.
Subscribe to:
Posts (Atom)