Home > Circuits > A > Oscillators - Astable

Oscillators:  Astable Schematics / Circuits

ALD555 Oscillation Circuit - Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc.

An SCR Flipflop  for Alternating Flashing Light Bulbs

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.

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

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

Astable Multivibrator (Bill Bowden) - Scroll to find this circuit.  This is an astable multivibrator circuits to alternately flash two LEDs.  The R & C values determines….

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.

Astable Multivibrator - The circuit diagram for the astable multivibrator using IC 555 is shown here. The astable multivibrator generates a square wave, the period of which is determined by the circuit external to IC 555. The astable multivibrator does not require any external trigger to change the state of the output. Hence the name free running oscillator. The time during which the output is either high or low is determined by the two resistors and a capacitor which are externally connected to the 555 timer.

Astable multivibrator lights LED from a single cell - 08/21/08 EDN-Design Ideas: A classical multivibrator drives a step-up inductor to power an LED from a single cell..

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...

CHEAP LOW POWER 3V 2Hz OSCILLATOR (62) (2hzosc)
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.

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 (124) (4584vco)
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.

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….

Flip Flop Circuit - In this project we examine one of the most valuable circuits to be invented, the flip flop. Originally it was designed with VALVES, along with its simpler version (without the two capacitors, called a bi-stable Multivibrator), it was realised it…

Flip Flop Flashers Buzzers Etc - 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...

Low Power Oscillators - This page has two unusual two-transistor oscillators.  I set the component values for a low frequency application.  Both circuits draw only about 1 microamp of current.

MICROPOWER C-MOS OSCILLATOR, DRAWS ONLY 0.5uA (6) (500na0)
If truly low power oscillators interest you, this circuit draws a mere 2 watts (500nA) from a 6v battery. It uses a very inexpensive C-MOS IC to produce a frequency of 2Hz. However, by changing the component values you can push it to 300Hz. The circuit draws much less current than traditional C-MOS oscillators using a Schmitt trigger inverter. It also produces fast leading edges. However, if you need more drive current, a C-MOS buffer should be included. Published in EDN, September 2, 1993.

Micropower CMOS Oscillator, Draws Only 0.5ua - If truly low power oscillators interest you, this circuit draws a mere 2 microwatts (500nA) from a 6v battery. It uses a very inexpensive C-MOS IC to produce a frequency of 2Hz. However, by changing the component values you can push it to 300Hz. The circuit draws much less current than traditional C-MOS oscillators using a Schmitt trigger inverter. It also produces fast leading edges. However, if you need more drive current, a C-MOS buffer should be included. Published in EDN, September 2, 1993. ….

Oscillator Draws 2 Nanoamps - This page shows two low frequency oscillators that draw ultra low current.

PRECISION ULTRA LOWER POWER OSCILLATOR (49) (10secosc)
This circuit works much like the classic 555 timer, but draws only about 1.5 microamps from a 3 volt battery. It is highly stable under varying temperature and supply voltages.

Precision Ultra Lower Power Oscillator - This circuit works much like the classic 555 timer, but draws only about 1.5 microamps from a 3 volt battery. It is highly stable under varying temperature and supply voltages.

Quad Astable Mode Operation Free Running Oscillator - Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. 

SCR Flipflop  for Alternating Flashing Light Bulbs

Ultra Low Current Oscillator - Here is a challenge.  Design an astable oscillator which draws only a few nanoamps of current from a +3v supply.  I gave this some thought and came up with the circuit below.  I used some pretty standard parts except for three surface mounted 1000M resistors I had on hand.  The oscillator frequency measured a low 1Hz frequency and the average current was a very low 3 nanoamps.  If I had some higher resistors values handy, I think I could have gotten the current down below one nanoamp. 

Ultra Low Power Astable Multivibrator - Taking advantage of some new voltage comparators, this circuit can produce a nice square wave signal while drawing only 1.6 microamps.  With the inclusion of a diode, the circuit can also produce short pulses instead of a square wave signal. 

VERY LOW POWER ASTABLE MULTIVIBRATOR (53) (astable)
This classic circuit draws only 200 nanoamps from a 1.5v supply.

Very Low Power Astable Multivibrator - This classic circuit draws only 200 nanoamps from a 1.5v supply.

Note: To report broken links or to submit your projects please send email to Webmaster

Discover

     more......