Electronic Circuits and electronic circuits, electronic schematics plus an extensive resource for hobbyists, inventors and engineers

DiscoverCircuits.com, has 40,000+ electronic circuits, cross-referenced
into 500+ categories.    We have searched the web to help you find quick design ideas.
We make every effort to link to original material posted by the designer. 
Please let us if you would like us to link to or post your design.

HOME Schematics Index Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches

Circuits designed by David Johnson, P.E.
Last Updated on: Monday, July 11, 2016 01:59 PM

Master Category List - Dave's Circuits

Text & Graphics Copyright © David A. Johnson, PE - ALL Rights Reserved.
LINKING to Dave's circuits is permitted but DO NOT COPY to your WEB SITE server!

Signal Generators Circuits
Signal Generator Circuits designed by David Johnson:
Page 1Page 2Page 3

10 Second 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 . . . [Circuit by David Johnson P.E.,  05/29/00]


100Khz Low Power Light Receiver  -  By starving a high speed logic inverter for current, this circuit can produce a sensitive 100KHz light receiver circuit, which is immune to ambient light, but only drawing 100 microamps from a 3 volt supply . . . [Hobby Circuit designed by David Johnson P.E.,  04/17/05]

125Khz LC Oscillator  -  This circuit adds more invertors in parallel to deliver more power. It is similar to CMOS INVERTERS FORM 125KHZ OSCILLATOR.  Please note that the values shown are for 125KHz. . . . [Circuit by David Johnson P.E.,  03/12/02]


125KHZ Medium Power Ocsillator  -  This circuit is similar to MEDIUM POWER 125KHZ OSCILLATOR but adds even more inverters in parallel to deliver yet more power.  The values shown are for 125KHz . . . [Hobby Circuit designed by Dave Johnson P.E.,  03/12/02]


125Khz Oscillator from CMOS Inverters  -  This circuit inverts the LC components so the inductor is grounded.  Two inverters are needed to produce the needed oscillation.  Again, the values shown set the frequency at 125KHz but can be changed to produce other frequencies . . . [Circuit by David A. Johnson P.E.,  03/12/02]


125khz Oscillator with Medium Power  -  This circuit adds even more inverters in parallel to deliver yet more power.  The values shown are for 125KHz . . . [Hobby Circuit designed by David Johnson P.E.,  03/12/02]


125Khz Ultra Pure Sine Wave Signal Source  -  For some RFID systems operating at 125KHz, a very low distortion signal source reference is needed.  The circuit shown on this page produces a 10-volt peak-to-peak signal into a 50-ohm load, with a distortion of only 0.01% . . . [Hobby Circuit designed by David Johnson P.E.,  02/11/02]


200Mhz-400Mhz Voltage Controlled Oscillator (VCO)  -  If you need a clean emitter coupled logic (ECL) type signal between 200MHz and 400MHz this circuit works fine. It uses four voltage-controlled capacitors to change the frequency . . . [Circuit by David A. Johnson P.E.,  03/19/99]


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 . . . [Circuit by David A. Johnson P.E.,  01/01/98]


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 maxim . . . [Circuit by David A. Johnson P.E.,  06/17/00]


40Khz Burst Laser Diode Driver  -  Some laser tag or simulated combat games can use this circuit to send short bursts of modulated laser light at the opponent's vest, equipped with a matching light receiver. The circuit operates from three 1.5v cells (4.5v) that should provide enough energy . . . [Hobby Circuit designed by Dave Johnson P.E.,  06/04/00]


40Khz LED Test Signal Generator  -  This 40KHz crystal controlled oscillator circuit drives an infrared LED with powerful 40ma pulses.  The circuit can be used to test optical communications circuits, designed to receive 40KHz modulated light signals . . . [Circuit by David Johnson P.E.,  02/14/02]


40Khz Precision Triangle Generator  -  This circuit generates a precision 40KHz triangle waveform . . . [Hobby Circuit designed by David A. Johnson P.E.,  07/09/06]


Astable Multivibrator with Very Low Power  -  This classic circuit draws only 200 nanoamps from a 1.5v supply . . . [Hobby Circuit designed by Dave Johnson P.E.,  06/10/00]


Astable Ultra Low Power Multivibrator  -  Taking advantage of some new voltage comparators, this circuit can produce a nice square wave signal while drawing only 1.6 micro Amps.  With the inclusion of a diode, the circuit can also produce short pulses instead of a square wave signal . . . [Hobby Circuit designed by David Johnson P.E.,  12/18/04]


Button Battery Cell Internal Resistance Measurement Circuit  -  The open cell voltage of a small silver oxide button cell battery remains very close to 1.5 volts over most of the life of the cell.  However, there is a relationship between battery health and the internal resistance of the cell. This circuit when used . . . [Circuit by Dave Johnson P.E.,  07/11/06]


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 maxim . . . [Hobby Circuit designed by David Johnson P.E.,  06/17/00]


CMOS Inverter 125khz LC Oscillator  -  This circuit uses a single CMOS inverter to form a series resonant LC oscillator.  The values shown set the oscillation at about 125KHz but the other frequencies are possible by changing the main LC values . . . [Circuit by David Johnson P.E.,  03/12/02]


CMOS Inverter forms a Resonant LD Oscillator   -  This circuit uses a single CMOS inverter to form a series resonant LC oscillator.  The values shown set the oscillation at about 125KHz but the other frequencies are possible by changing the main LC values . . . [Hobby Circuit designed by David A. Johnson P.E.,  03/12/02]


CMOS Inverter Parallel LC Oscillator  -  I have used this parallel resonant LC oscillator circuit countless times.  The oscillator frequency is determined by the inductor and capacitor values.  I have shown an adjustable inductor to make it easy to set the frequency to a specific value . . . [Circuit by David A. Johnson P.E.,  03/12/02]


CMOS Inverters Form 125Khz Oscillator  -  This circuit inverts the LC components so the inductor is grounded.  Two inverters are needed to produce the needed oscillation.  Again, the values shown set the frequency at 125KHz but can be changed to produce other frequencies . . . [Hobby Circuit designed by David Johnson P.E.,  03/12/02]


CMOS Nand Gate Forms Gated 125Khz Oscillator  -  This circuit is uses a NAND gate as an inverter.  The gate allows the oscillator to be gated on and off.  Again, the values shown set the frequency at 125KHz but can be changed to produce other frequencies . . . [Circuit by Dave Johnson P.E.,  03/12/02]


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 . . . [Hobby Circuit designed by David A. Johnson P.E.,  06/03/00]


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 . . . [Circuit by David Johnson P.E.,  12/01/02]


Crystal Controlled 1KHz Signal Generator  -  A while back I got an email from a Discover Circuits visitor.  He needed a way to calibrate a RPM display for a big diesel engine.  The engine had a tachometer output which produced 12 pulses per rotation with an Amplitude of about 5v RMS.  The full scale reading on the engine’s RPM speed display dial was 5,000 . . . [Circuit by David Johnson P.E.,  05/01/12]


ELC signal between 200Mhz-400Mhz  -  If you need a clean emitter coupled logic (ECL) type signal between 200MHz and 400MHz this circuit works fine. It uses four voltage-controlled capacitors to change the frequency . . . [Hobby Circuit designed by David Johnson P.E.,  03/19/99]


Flexible Outputs from Square Wave Driver  -  This circuit can produce an output signal ranging from DC to 100KHz. It can source a voltage ranging from 1v to 30v. It can sink a voltage ranging from zero volts to –30v. It can drive up to 200ma of current and can even be switched to a floating tristate . . . [Hobby Circuit designed by David Johnson P.E.,  07/08/00]


Gated 125Khz Oscillator  -  This circuit is uses a NAND gate as an inverter.  The gate allows the oscillator to be gated on and off.  Again, the values shown set the frequency at 125KHz but can be changed to produce other frequencies . . . [Hobby Circuit designed by Dave Johnson P.E.,  03/12/02]


Gated Crystal Oscillator with Very Low Power  -  The circuit gates the output of a continuously operating 32KHz crystal oscillator to the input of a C-MOS buffer when clock pulses are needed. The technique gets around the problem of a slow starting crystal oscillator by keeping the oscillator going and switching on a transistor power stage only as needed . . . [Hobby Circuit designed by David A. Johnson P.E.,  06/03/00]


Highly Stable 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. . . . [Hobby Circuit designed by David A. Johnson P.E.,  05/29/00]

 

Dave's Signal Generator Circuits: 
Page 1,    Page 2,    Page 3

Signal Generators Circuits

Find Dave's Circuits by Category
eMail David A. Johnson, P.E. about these circuits




HOME Schematics Index Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches


 About Us   |  Advertise on DiscoverCircuits.com   |   Report Broken Links  |    Link to DiscoverCircuits.com  |    Privacy Policy

The circuits on this site are designed by David A Johnson - unless otherwise noted.  David A. Johnson & Associates.  All Rights reserved. 
 Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.