Astable Oscillator Electronic Circuits

Oscillators: Astable Circuits, Page 1
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Oscillator Circuits -- Main Page
Last Updated on: Monday, October 03, 2011 06:07 PM

Circuits Designed by Dave Johnson, P.E. :

CHEAP LOW POWER 3V 2Hz OSCILLATOR
This is yet another method to generate low frequency output pulses. The circuit uses an inexpensive under-voltage monitor IC and a couple of cheap MOSFETs. It could easily be modified to produce pulse frequencies from about one cycle per minute to a maximum of about 10KHz. It draws only about 1uA from a 3v battery. This circuit should not be used if frequency stability is important, since it will change as a function of supply voltage.

CMOS SCHMITT TRIGGER IC MAKES VCO
By changing the supply voltage fed to a classic 4584 Schmitt trigger type oscillator, the oscillator frequency can be changed over a range of 50:1. A 74HCU04 inverter is used at the output of the 4584 to maintain a constant TTL logic level signal.

Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

3 Volt Low Battery Voltage Flasher - This circuit is designed to monitor two alkaline cells (3v) that form the battery often used in portable electronic equipment....[Designed by David A. Johnson]

ALD555 Oscillation Circuit - Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc....[App Note]

An SCR Flipflop for Alternating Flashing Light Bulbs - ….(electronic schematic added 12/08)

Astable Flip Flop Circuits (techlib) - Several circuits here. The familiar astable flip-flop circuit is a handy configuration for making flashers or generating squarewaves. Here is a typical alternating LED flasher with the LEDs in the emitters instead of collectors as is normally done. The bias resistors are directly connected....(added 04/05/06)

Astable Mode Operation 50% Duty Cycle - Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc....[App Note]

Astable Mode Operation Free Running Oscillator - Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc....[App Note]

Astable Multivibrator - The capacitor C charges via R1 and R2 and when the voltage on the capacitor reaches 2/3 of the supply, pin 6 detects this and pin 7 connects to 0v. The capacitor discharges through R2 until its voltage is 1/3 of the supply and pin 2 detects this and turns off pin 7 to repeat the cycle....

Astable Multivibrator - As shown in the schematic diagram here, the astable multivibrator simply extends the modification that converted the bistable multivibrator to a monostable version of the circuit. Now, both transistors are coupled to each other through capacitors. Whichever transistor....(electronic circuit added 7/03)

Astable Multivibrator (Bill Bowden) - Scroll to find this circuit. This is an astable multivibrator circuits to alternately flash two LEDs. The R & C values determins….(electronic schematic / circuit added 4/02)

Astable multivibrator (blinkie) - A pulse generator, or astable, circuit can be made using four resistors, two capacitors, two LEDs and two transistors. 'Blinkie' uses these components to form a face, with the flashing LEDs representing the eyes. (electronic design added 08/08/08

Astable multivibrator gets hysteresis from positive feedback stage - 22-Oct-09 Issue of EDN Add hysteresis through positive feedback.... [Design Idea by Robert Larson, Seattle, WA]

Astable multivibrator lights LED from a single cell - 21-Aug-08 Issue of EDN A classical multivibrator drives a step-up inductor to power an LED from a single cell.... [Design Idea by Luca Bruno, ITIS Hensemberger, Monza, Lissone, Italy]

Astable Multivibrator Projects - Astable or free-running multivibrators have been used in home-built amateur radio equipment for many years. The basic circuit is a two stage amplifier with AC-coupled feedback from output to input. One transistor stage is on ( conducting current ) while....(designed added 08/08/08)

Cheap Low Power 3v 2hz Oscillator - This is yet another method to generate low frequency output pulses. The circuit uses an inexpensive under-voltage monitor IC and a couple of cheap MOSFETs. It could easily be modified to produce pulse frequencies from about one cycle per minute to a maximum of about 10KHz. It draws only about 1uA from a 3v battery. This circuit should not be used if frequency stability is important, since it will change as a function of supply voltage.... [Designed by David A. Johnson]

CMOS Schmitt Trigger IC Makes VCO - By changing the supply voltage fed to a classic 4584 Schmitt trigger type oscillator, the oscillator frequency can be changed over a range of 50:1. A 74HCU04 inverter is used at the output of the 4584 to maintain a constant TTL logic level signal …. [Designed by David A. Johnson]

Dummy Alarm - This project makes a superbright LED flash briefly once every 5 seconds to imitate the indicator light of a real alarm. The circuit is designed to use very little current to prolong battery life so that it can be left on permanently. This is a simple project, ideal for a beginner.... [Designed by John Hewes]

Oscillators: Astable Circuits: #'s - D E - S T - Z