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555-556 Timer info

555 Introduction

The 555 IC is a timer IC and it is very popular integrated circuit.

The IC is just 8 pin  in line package, and includes 23-transistors, 2-diodes and 16resistors.

the other timer IC 556 is a 14 pin and includes  two 555 timers on a-single-chip.

also available are ultralow power types of the 555 timer.

The 555 timer has 2 operating modes:

555 MONOSTABLE MODE:
in this mode the 555 functions as a "ONE - SHOT." applications include timers, missing pulse detection,touch switches, bouncearee switches,  and etc...

555 ASTABLE MODE:
in this mode 555 timer can operate as an oscillator.

it can bu used these functions:
  • pulse generation
  • LAMPand LED flashers
  • generation of tone
  • logical clocks
  • alarms

etc.

CIRCUIT ASSEMBLY TIPS:

build test versions of circuits on plastic solderless breadboard before making them parmanent. in monostable circuits where false triggering might couse problems, the pin 5 to ground via a 0,1 micro Farad capacitor. place a 0.1 micro farad capacitor accross pins 1 and 8 if power leads are long or if a circuit seems to_malfunction.

a 1 micro farad capacitor may alsobe necessary. be sure to experiment aith values of timing resistors and capacitors. the basic circuits on PP 6-7 explain the role these components play. remember that these 556 replace two 555's. low power versions of the 555 may require some revisions to standart 555 circuits.

555 SPECIFICATIONS 1
Supply Voltage (Vcc) = 4.5 T0 15 V
Supply Current (Vcc=+5V))2 = 3 T0 6 mA
Supply Current (Vcc=+15V))2= 10 T0 15 mA
Output Current = 200 mA (maximum)
Power Dissipation = 600mW
Operating Temperature= 0 - 70 C

1= Values Shown apply to Ne555 (8 pin mini Dip)
2= Output Current =0

Keywords : NE555, Timer, Multivibrators, Astable, Monostable, Bistable
Writer : delon  |
7 Apr 2006 Fri   
|  20.697 Views
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