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

DiscoverCircuits.com has links to 45,000+ electronic circuits, cross-referenced
into 500+ categories.    We have searched the web to help you find quick design ideas.

HOME Schematics Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches
Welcome to DiscoverCircuits.com - online since 2002

See Media Kit for
Advertising Opportunities

Attention Designers:  Please alert us by eMail if we have linked to sites
where your original material has been copied without your permission.
We will change to the LINK to your site.  
Thank you.

 


Control Circuits

 
#'s - A       B - C       D - G        H - L       M - P        Q - S        T - U        V - Z
 

Last Updated: October 24, 2017 02:54 PM

Circuits Designed by Dave Johnson, P.E.

Solar-Powered Pump Motor ControllerA Discover Circuits visitor had a problem.  He needed a simple on/off controller for his solar powered water pump.  His system used two 12v 50 watt solar panels wired in series.  The power from the solar panels drove a submerged water pump.  However, during. . . Circuit by David Johnson P.E.-October, 2010

Solid State Relay Requires Only 50ua Drive CurrentThis circuit demands a control current that is 100 times smaller than that needed by a typical optically isolated solid state relays.  It is ideal for battery-powered systems.  Using a combination of a high current TRIAC and a very sensitive low current SCR. . . Circuit by David A. Johnson P.E.-June, 2000

Sound Triggered Night LightA while back, I received a schematic from a guy by the name of Karl.  He described a situation he and his wife found themselves in aboard a cruise ship in the Caribbean.  They were staying in a room toward the inside of the ship, which did not have any port holes, windows or a balcony. . . Circuit by Dave Johnson P.E.-August, 2013


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

Soft Start for Power Amps -  Although the soft start circuit can be added to any sized transformer, the winding resistance of 300VA and smaller transformers is generally sufficient to prevent a massive surge current.  Use of a soft start circuit is definitely recommended for 500VA and larger transformers __ Designed by Rod Elliott  ESP

Soft Switching Amplifier with Tone Controls -  Built around an LM380, this amplifier includes tone controls and electronic "soft switching".  The soft switching circuitry ensures power is built up gradually eliminating the dc thump __ Designed by Andy Collison

Soft-start controller is gentle on loads -  11/22/01 EDN-Design Ideas The control circuit in Figure 1 senses a given load and automatically soft-starts the load by synchronously adjusting the power to that load.  You can also manually adjust the power delivered to the load by controlling the phase angle of the line voltage across the load.  The phase-angle adjustment for every ac half cycle covers 0 to 180° __ Circuit Design by Douglas Sudjian, Resonext Communications Inc, San Jose, CA

Solar Charged LED Utility Light -  Tired of always spending money on flashlight batteries only to have them fail just when you need them? Try this simple circuit out.  It would make an excellent science fair project.  The white LEDs are quite bright, they provide enough light to illuminate a small room at night.  The LEDs produce a nicely focused beam.  You can read by the light of this device.   __ Designed by G. Forrest Cook

Solar Engine that is MicroPower -  Voltage-Controlled Solar Engine: Ken Huntington's fairly complex, but very efficient "micropower" solar engine design.  No 1381s or ICs needed.   __ Designed by Ken Huntington

Solar Flasher -  This circuit is a single transistor flyback (Joule Thief) circuit that features a third coil.  With it, flash duration and brightness is much enhanced, without resorting to large value capacitors.  The performance can be seen in the following Videos (on Youtube) : http://www.  youtube.  com/watch?v=tgcYcPdBwNo __ Designed by QS

Solar Panel Charge Controller / Low Voltage Disconnect -  The SPC3 is a solar power center, it can handle all of the power functions for a solar charged 12 Volt DC system. The SPC3 contains a 9 amp photovoltaic charge controller, a 10 amp low voltage load disconnect circuit and a pair of built-in white LEDs for area illumination. The low voltage disconnect circuit has a load on-off switch and a battery low voltage indicator. By using the SPC3 as the center of a solar powered device, long battery life is assured. The SPC3 can be used for a stand-alone solar lighting system, it can also be used for making solar powered audio and radio devices. __ Designed by G. Forrest Cook

Solar Panel Charging 12V Battery through Ideal Diode to Prevent Back Feeding -  In solar power systems, Schottky diodes are used to prevent discharge of the battery during hours of darkness.  Unfortunately, the voltage drop and power dissipation of a Schottky diode can be quite large when used with high wattage solar panels, thus reducing the amount of power available to charge the battery.  This circuit__ Linear Technology/Analog Devices App Note, Jun 15th 2010

Solar-Array Controller Needs No Multiplier to Maximize Power -  12/05/08 EDN-Design Ideas Relying on the logarithmic behavior of transistor junctions to calculate power, this controller operates a photovoltaic array at its maximum power point __ Circuit Design by W Stephen Woodward, Chapel Hill, NC

SolarbotICs NV-Based -  uses a single IC (and it's a common one, too -the 74AC240) to give you motor drive in a single direction
 __ Designed by Wilf Rigter

Solar-powered Motor runs on 10 nA -  18-Mar-04 EDN-Design Ideas Designs for solar-powered applications with low-duty-cycle requirements can often rely on capacitors for energy storage in place of less reliable batteries.  Typical applications include solar positioning, telemetry transmitters, chemical pumps, data loggers, and solar-powered toys.  The circuit in Figure 1 can run a small pager motor from the output of a small calculator-type solar cell in near __ Circuit Design by Stepan Novotill, Victoria, BC, Canada

Solar-Powered Pump Motor Controller -  A Discover Circuits visitor had a problem.  He needed a simple on/off controller for his solar powered water pump.  His system used two 12v 50 watt solar panels wired in series.  The power from the solar panels drove a submerged water pump.  However, during. . . Circuit by David Johnson P.E.-October, 2010

Solar-Powered Sensor Controls Traffic -  26-Nov-09 EDN-Design Ideas A traffic-sensor post measures vehicle location and speed at an intersection, providing an accurate, effective, inexpensive approach to monitoring traffic flow __ Circuit Design by Larry K Baxter, Capsense, Lexington, MA

Soldering iron driver bridge controls temperature -  09/06/13   EDN-Design Ideas With a power supply and a replacement soldering handle you can implement this temperature-controlled soldering iron driver.  One way you can control the temperature of a soldering iron is with a microcontroller, using temperature feedback from the thermistor in the handle near the iron's tip.  This Design Idea presents a soldering iron driver that does this using only analog components.   __ Circuit Design by Kiril Karagiozov

Soldering Iron Temperature Controller -  Here is a simple circuit to control the temperature of a soldering iron.  It is especially useful if the soldering iron is to be kept on for long since you can...__ Electronics Projects for You

Solid State 120 VAC Lamp Chaser -  This circuit is basically the same as the 10 channel LED sequencer with the addition of solid state relays to control the AC lamps.  The relay shown in the diagram is a Radio Shack 3 amp unit   (part no.275-310) that requires 1.2 volts DC to activate.  No current spec was given but I assume it needs just a few __ Designed by Bill Bowden

Solid State Auto Power-Off On Mains Failure -  A good number of circuits which turn off the power to the load on mains failure have already appeared in EFY.  This circuit is different because it consumes no power when...__ Electronics Projects for You

Solid State Power Controller -  The ckt is built around two 555 timer ICs. U1 and U2. U1 is wired as a variable duty cycle oscillator with a constant time period of around 0.1 second. Duty cycle can be varied from 0 to 100 per cent by R4 potentiometer. The output of U1 (pin 3) is connected to the rest input (pin 4) of U2. __ Designed by  Ravi Sumithraarachchi

Solid State Relay Requires Only 50ua Drive Current -  This circuit demands a control current that is 100 times smaller than that needed by a typical optically isolated solid state relays.  It is ideal for battery-powered systems.  Using a combination of a high current TRIAC and a very sensitive low current SCR. . . Circuit by David A. Johnson P.E.-June, 2000

Solid State Relay Space Heater Controller -  The space heater controller pictured above uses a 25 amp Solid State relay, a dual op-amp and a few other parts.  The circuit board was laid out on graph paper to work out locations for the holes.  The hole positions were then copied to a bread board to be used as a template for drilling the holes.  The bread board was then clamped on the top of the blank copper board as shown in the top picture and the marked holes were drilled using the bread board as a guide for the drill (no walking).  The drilled board was then sectioned into isolated islands using a dremel tool and router bit as shown __ Designed by Bill Bowden

Solid State Remote Control Switch -  Here is a solidstate remote control switch which uses readily available electronic components.  The control circuit comprises the transmitter and receiver sections.  The range of the transmitter is around seven metres.  The transmitter...__ Electronics Projects for You

Solid State Reversing -  This circuit uses solid state switching (transistors) to control direction of a DC motor.  You have precise control of the movement of the motor, and an indication of direction provided by LED's.   __ Designed by Andy Collison

Solid-State Flasher Has Short-Circuit Protection -  01/16/97 EDN-Design Ideas The circuit in Figure 1 switches an inductive or resistive grounded load using a bootstrapped, n-channel, power MOSFET.  The circuit features short-circuit, reverse-polarity, and transient-input-voltage-spike protection.  The input voltage, VDD, can vary from about 18 to 30V, and the circuit can handle as much as approximately 10A with proper heat sinking of the FET.  The circuit flashes at a rate of about 100 flashes/minute, with a duty cycle of about 47%.  You can use this circuit as a solid-state flasher for vehicles with 24V nominal-power systems. __ Circuit Design by Navdhish Gupta, TDF Corp, Naperville, IL

SOT-23 Smbus Fan Speed Controller Extends Battery Life & Reduces Noise -  DN238 Design Notes__ Linear Technology/Analog Devices

Sound Activated Relay #1 -  This relay remains dormant until the op-amp activates upon sound via the electret-microphone.  I only tested the 2-wire type.  The input stage is a regular off-the-shelf 741 operational amplifier and connected as a non-inverting follower audio amplifier.   __ Designed by Tony van Roon  VA3AVR

Sound Activated Relay #2 -  This relay remains dormant until the op-amp activates upon sound via the electret-microphone.  Only tested with the 2-wire type.  The input stage is a regular off-the-shelf 741 operational amplifier and connected as a non-inverting follower audio amplifier __ Designed by Tony van Roon  VA3AVR

Sound Activated Switch -  This project is a sound activated switch.  Description Clap switch/Sound-activated switch designed around op-amp, flip-flop and popular 555 IC.  Switch avoids false triggering by using 2-clap sound.  Clapping sound is received by a microphone, the microphone changes the sound wave to electrical wave which is further amplified by op-amp.555 timer IC acts as mono-stable

Sound Controlled Flip Flop -  Described here is a very inexpensive solution to many phono-controlled applications like remote switching on, for instance, or activating a camera, tape recorder, burglar alarms, toys, etc.  The circuit given here employs a condenser microphone as the pick-up.  A two-stage amplifier built around a quad op-amp IC LM324 offers a good gain to enable sound pick-up upto four metres.  

Sound Level Indicator -  This project uses an LM3915 bar-graph IC driving two sets of ten LEDs for a 30dB range. The circuit is unique because it has an additional range of 20dB provided by an automatic gain control to allow it to be very sensitive to low sound levels but it increases its range 20dB for loud sounds. __ Designed by Audioguru

Sound Operated Switch -  This sensitive sound operated switch can be used with a dynamic microphone insert as above, or be used with an electret (ECM) microphone. If an ECM is used then R1 (shown dotted) will need to be included. A suitable value would be between 2.2k and 10kohms. __ Contact: IQ Technologies

Sound operated switch -  This sensitive sound operated switch can be used with a dynamic microphone insert as above, or be used with an electret (ECM) m`icrophone.  If an ECM is used then R1 (shown dotted) will need to be included.  A suitable value would be between 2.2k and 10kohms.  The two BC109C transitors form an audio preamp, the gain of __ Designed by Andy Collison

Sound triggered flash -  If you wish to take a picture of a fleeting event which generates a sound, you can do it with this sound activated trigger.  It does not require any power supply: it feeds on the high voltage available on the flash trigger terminal.  Any economic ceramic microphone is suitable for the purpose

Sound Triggered Night Light -  A while back, I received a schematic from a guy by the name of Karl.  He described a situation he and his wife found themselves in aboard a cruise ship in the Caribbean.  They were staying in a room toward the inside of the ship, which did not have any port holes, windows or a balcony. . . Circuit by Dave Johnson P.E.-August, 2013

Sound-Operated Intruder Alarm -  When this burglar alarm detects any sound, such as that created by opening of a door or inserting a key into the lock, it starts flashing a light as well as...__ Electronics Projects for You

Sound-Operated Switch for Lamps -  This inexpensive, fully transistorised switch is very sensitive to sound signals and turns on a lamp when you clap within 1.5 metres of the switch.  One of its interesting applications is...__ Electronics Projects for You

Special Effects from a Six Pack -  Four channel Sequencer to Analog Dimmers and idea how to couple relay to the circuit

Speed Control Of DC Motor using Pulse-Width Modulation -  Pulse-width modulation (PWM) or duty-cycle variation methods are commonly used in speed control of DC motors.  The duty cycle is defined as the percentage of digital ‘high’ to digital ‘low’ plus...__ Electronics Projects for You

Speed Controller -  There are many ways of producing a PWM wave form, it can be done with PIC’s, 555 timers, Nand gates and schmitt triggers, but I’ve taken the easy way out by using a custom made PWM motor controller (in kit form) and modifying it (slightly)

      <<<         >>>

Control Circuits:   #'s - A       B - C       D - G        H - L       M - P        Q - S        T - U        V - Z

 


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


Discovercircuits.com endeavors to credit original designers.   Please alert us by eMail so we can
delete links to material that have been copied without your permission
.   Thank you.


© Copyright of all original material on this website is the property
of David A. Johnson, P.E. (Dave Johnson & Associates ) unless otherwise noted.  

Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.
All material is provided "as is" without guarantees or warranty of any kind, either expressed or implied.