Forum Diagram: flasher

Showing posts with label flasher. Show all posts

Saturday, November 15, 2014

FLASHER CIRCUIT USING NE 555

Flashing circuits are very interesting. They grab your attention and can be used in many applications. They consume very little energy and a single cell can last as long as 12 months. You can flash globes, LEDs and pulse all types of devices such as motors, solenoids and piezo diaphragms. In this discussion we will cover a number of interesting "oscillator circuits." They can be adapted for other applications - but to do this you have to know how they work. This is not easy as most of them are quite complex. In fact oscillator circuits are one of the most difficult circuits to understand. But if you read the text, everything will become clear.

Circuit Description

This is the circuit diagram of lamp flasher operated from mains. By this you can flash up to 200 Watt lamps at rates determined by you. IC NE555 is wired as an astable multivibrator for producing the pulses for flashing the lamp. The flashing rate can be set by the value of resistors R2 & R3.

Diodes D1 & D2 provides a half wave rectified regulated supply for the IC. Transistor T1 is used to drive triac and triac BT136 for driving the load. Resistor R4 limits the base current of Q1.

Flashing Circuit Diagram & Parts List

Notes

Assemble the circuit on a good quality PCB or common board.
Connect a 100K pot instead of R2 if you need frequent changes in rate.
Many parts of the circuit are live with potential shock hazards. So please be careful.
As usual use an IC holder for mounting the IC.

Friday, October 17, 2014

1 5 volt dual LED flasher

This 1.5 volt led fasher runs more than a year on a single d" cell and alternately flashes 2 LEDs at about a 1 second rate. The circuit employs a 74HC14 CMOS hex inverter that will operate at very low voltages (less than 1 volt). One section is used as a squarewave oscillator (pins 1 and 2), while the others are wired to produce a short 10mS pulse on alternate edges of the square wave so the LEDs will alternate back and forth. The output sections each use a capacitor charge pump to increase the voltage for the LEDs. The circuit draws an average current of 800uA from the D battery and the LED peak current is about 40mA with a fresh battery and drops to about 10mA as the battery voltage falls to 1.1 volts. The capacity of a alkaline D cell is about 12 amp hours with a cutoff voltage of 1.1 so the circuit should run about 12/.0008 = 15000 hours or maybe 625 days, but I havent verified that yet. The idea for this circuit came from a single 1.5 volt LED flasher by Dave Johnson that can viewed at

Author : Bill Bowden

Thursday, October 16, 2014

Light Flasher

This is a very basic circuit 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).

Sunday, August 17, 2014

Led or Lamp Flasher Circuit

This schema was designed to provide that continuous light lamps already wired into a schema, become flashing. Simply insert the schema between existing lamp and negative supply. Especially suited for car or panel pilot lights, this device can drive lamps up to 10W.

Parts:

R1 = 6.8K
R2 = 270K
R3 = 220K
D1 = 1N4002
C1 = 220uF-25V
C2 = 10uF-25V
Q1 = BC557
Q2 = BD139
B1 = Any type in the range 3-24V
B1 = Suited to the lamp adopted
LP1 = Filament Lamp 10W-3V to 24V
SW1 = On-Off Switch

Notes:

* Break lamp to negative supply connection, and then insert the schema between existing lamp connection and negative supply (respecting polarities!).
* C1 value can be varied from 100 to 1000µF or higher, in order to change flashing frequency.
* Although rather oversized, this schema can also drive any LED, providing a suitable resistor is fitted in series with the light emitting device.
* The resistor should lie in the 47R to 2K2 range, depending on supply voltage.

Thursday, August 14, 2014

LED 230 V Flasher Circuit diagram

This schema operates with 230v.you can use this schema to decorate your parties.I think this will be a wonderful schema to you all.This schema was taken from my old schema book called 100 schema book.Here DIAC ER 900 and Triac BTW 11-400.

230 V Flasher Circuit diagram