Control Circuits starting with J-O

Control Circuits Page 4
Control Circuits: #-B C D-G H-I J-O P-Q R S T U-V W-ZLast Updated on: Friday, October 16, 2009 03:41 AM

Circuits Designed by Dave Johnson, P.E. :

Low Voltage H-bridge
TTL type Q and inverted Q inputs control a classic H-bridge circuit, rated at 50 volts and about 10 amps. The circuit can control power and direction of a DC motor. (added 7/06)

Motor Brake
This circuit will bring a fast moving DC motor to a stop in seconds. The braking action is automatically applied whenever DC power is removed. (added 12/04)

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

Japanesque Ceiling Light - This is a Japanesque ceiling light without any electronics. Everybody will able to build easy even if they have no electronic skill. (added 10/05)

Joy Stick Controlled Modernized Toy Throttle - (circuit / schematic design added 6/06)

Keypad Controlled Switch No. 2 - This is a simplified version of the 4-Digit Keypad Controlled Switch. I have modified the design to reduce the complexity of the circuit - and the number of components required. As a result - the code is somewhat less secure. However, there should be lots of situations where it will still be adequate. (circuit design added 08/08/08)

Laboratory Control System for Cold Atom Experiments - We have developed a powerful yet inexpensive and easy to construct experiment control system. The construction of the system together with the control software is described here. All circuits and software are free to download and use for nonprofit.... (added 04/05)

Laptop Power Supply - (application / block diagram added 6/07)

Large capacitor charge "controllers" (Car Audio) - Here's a basic cap switch that will connect capacitor to ground only when it's charged to within 0.4-0.7V from battery voltage (otherwise, it's charging through a 22 Ohm resistor, which can be a low-power 12V lightbulb, too)....(electronic design added 6/07)

Layout and Grounding Recommendations for Touch Screen Digitizers - AN-577 Analog Devices Application Notes (app note added 2/06)

LED Bargraph Optical Tachometer - For the electric R/C enthusiast, a tachometer can be a very useful piece of equipment. When I first built this tach back in 1995, it was essential, as there were very few off-the-shelf electric R/C power systems that just worked….(circuit added 09/06)

LED Driver provides software ControlLED intensity - 09/30/04, EDN-Design Ideas: Recent advances in operating efficiency have expanded the use of LEDs from one of mere indicators to becoming driving forces in electronic lighting. Increased reliability and ruggedness (versus other lighting technologies)gives the LED a bright future indeed. Vendors in recent years have introduced many ICs for driving LEDs, but the problem of driving serial chains of LEDs has received less at.....(design idea added 10/05)

Leslie Speaker controller - Very basic but viable Leslie Speaker controller. Includes noise-abatement components, to ensure smooth, quiet Tremelo/Chorale transistions. (circuit design added 9/06)

Level Crossing Lights - Every model railway has a place where road and rail meet, and when it does, some form of warning is needed. Flashing lights work well, but something is needed to drive them. And that is where this circuit comes in. All it does is flash lights and it is so simple anyone could build it!...(design added 10/06)

Light Activated Relay (Bowden) - This is same circuit as above with the addition of a photo resistor to trigger the flip flop instead of a push button. The bias resistor in series with photo resistor was chosen so that sufficient voltage is present at the base of the 2N3904 to supply current to the circuit in ambient lighting conditions...(electronic circuit added 4/05)

Light bulb timer - The circuit is rather small and could be housed in the same case as the push button, if there is enough room. Of course you have to substitute the standard switch with a push button. Operation with a 110Vac mains has not been tested although I expect that a 100μF 100V capacitor instead of the 47μF capacitor should do the trick....(circuit added 03/09)

Light Control System - ….(circuit design added 08/08)

Light Controlled Switch - output a control signal suitable for relay depending on the light level (added 5/02)

Light Controller Variations - Diagrams are for12V operation and there are high side (common ground) and low side (common +12V) versions (added 5/02)

Light Organ for Car - flashes3 low voltage lights, operates at10-25-Volt voltage, in PDF format, text in Finnish (added 4/02)

Lights timer - Automatically turn off the lights after 10 minutes. If you often forget to turn off the lights outside or at different places in the house, this circuit can be practical for you. It can control two independent light switches with different turn off times. Press the button once and the light turns on for the preset time. Press again, and the light remains on forever. Press for the third time, and the light turns off.....(design added 05/09)

Limit switches control DC motor H bridge - 03/05/09, EDN-Design Ideas: - Mechanical and electronic switches provide interlocks, preventing motors from overrunning their bounds.....(design idea added 08/09)

Line Following Robot - This is a tiny line following robot which can run on the desk. (added 10/05)

Linear Voltage Fan Speed Control using Microchip's TC64x Family TC642, TC646, TC648 - Microchip Application Note Published 27-Jul-04 (app note added 6/06)

Linux Infrared Remote Control LIRC - (design circuit added 8/02)

LM5068-48V Hot Swap Controller - National Semiconductor Application Note (app note added 2/06)

Load Switcher Draws Only 6 µA - 07/04/96, EDN-Design Ideas: (design idea added 3/03)

Long Range Infrared Remote - 4 channel remote control using MC145026, MC145027. (circuit added 8/06)

Low loss circuit powers solar lantern - 04/01/04, EDN-Design Ideas: The solar-lantern circuit in Figure 1 is a low-loss configuration that uses a 7W, four-pin CFL compact fluorescent lamp and a 12V, 7-Ahr, sealed, maintenance-free battery. The inverter features greater-than-85% efficiency, less-than-2-mA quiescent current, and a shunt-charge controller with deep-discharge and overcharge protection for the battery.....(design idea added 04/04)

Low Noise AC Amplifier has Digital Control of Gain and Bandwidth - 02/05/04, EDN-Design Ideas: In low-noise analog circuits, a high-gain amplifier serves at the input to increase the SNR. The input signal level determines the input-stage gain; low-level signals require the highest gain. It is also standard practice in.....(design idea added 6/06)

Low Voltage H-bridge - TTL type Q and inverted Q inputs control a classic H-bridge circuit, rated at 50 volts and about 10 amps. The circuit can control power and direction of a DC motor. (added 7/06) ….(designed by David A. Johnson)

Low Voltage Hot Swap Controller Ignores Backplane Noise and Surges - DN319 Design Notes (Linear Technology) (app note added 1/06)

Low-Cost Bidirectional Brushed DC Motor Control using the PIC16F684 - Microchip Application Note Published 16-Dec-03 (app note added 2/06)

Low-Cost DC Motor Speed Control with CMOS ICs - Microchip Application Note Published 12-Nov-02 (app note added 2/06)

Low-Noise Low Drop-Out Regulator for Portable Equipment - AN-262 Analog Devices Application Note (app note added 6/06)

Low-Voltage Continuity Tester - Several simple circuits were tried -a lamp, battery and probes still demanded the attention of the eyes; replacing the lamp with a buzzer was more successful but needed some three to four volts and gave no indication of a series semiconductor....(Tony van Roon's electronic design added 2/06)

LT1166: Power Output Stage Automatic Bias System Control IC - DN126 Design Notes (Linear Technology) (app note added 1/06)

LT1575 Ultrafast Linear Controller Makes Fast Transient Response Power Supplies - AN69 Linear Technology AN69 describes considerations for linear regulators based on the LT1575 UltraFastTM Linear Regulator controller. The LT1575 drives an external MOSFET pass transistor as an overdriven source follower. This configuration results in an extremely high speed regulation ....(app note add 2/06)

LT1619: Tiny Boost Controller Provides Efficient Solutions for Low Voltage Inputs - DN255 Design Notes (Linear Technology) (app note added 1/06)

LTC1645 Dual Channel Hot Swap Controller/Power Sequencer - DN217 Design Notes (Linear Technology) (app note added 2/06)

LTC1646: Power Supply Isolation Controller Simplifies Hot Swapping the CompactPCI Bus for 5V-/3.3V-Only Applications - DN253 Design Notes (Linear Technology) (app note added 2/06)

LX1720: High-Efficiency Class-D, Stereo Audio Amplifier Controller IC. Summary AN-11 - Application Note 11 from Microsem (app note added 6/06)

Mains Clock Controller using AT89C2051 1 - (circuit / schematic design added 6/06)

Mains Clock Controller using AT89C2051 2 - 12/04/97, EDN-Design Ideas: (design idea added 6/06)

Make a simple ramp generator for stepper motors - 04/04/02, EDN-Design Ideas: Stepper motors are synchronous motors that step at the pulse rate of the driving signal. For the motor to move quickly, the stepping rate must be fast.....(design idea added 6/06)

MicroController controls analog phase shifter - 06/12/08, EDN-Design Ideas: By using a digital potentiometer in a phase-shift circuit, a microcontroller can precisely control phase shift.....(design idea added 09/08)

MicroController controls multichemistry battery charger - 09/28/00, EDN-Design Ideas:.....(design idea added 11/05)

MicroController drives H bridge to power a permanent magnet DC motor - 03/15/07, EDN-Design Ideas: Improved H-bridge requires only two driver signals.....(design idea added4/07)

MicroController or DSP Circuit Controls On/Off Function - 11/13/03, EDN-Design Ideas: In many applications, a single on/off button switches the power supply on or off. Usually, the system switches off regardless of the processing function or workload the microcontroller or DSP circuit is currently handling.....(design idea added 1/05)

MicroController Produces Analog Output - 10/16/03, EDN-Design Ideas: A brushless dc motor needs several voltage levels to control its speed: 0V to stop the motor, 5V to run it at maximum speed, and some voltages between these extremes to run it slower.....(design idea added 02/05)

MicroController takes control of comparator - 09/01/00, EDN-Design Ideas:.....(design idea added 11/05)

MicroController Visualizes Hex Code - 04/27/00, EDN-Design Ideas:.....(design idea added 11/05)

MicroController Watches Controls AC Power - 06/22/95, EDN-Design Ideas: -circuit allows an isolated microcontroller to both sense and control ac power to an externally plugged-in device (added 3/03)

MIDI Controlled Switches - can drive up to 128 individual relays, solenoids, motors, etc. with a MIDI note-on and note-off messages (added 6/06)

MIDI Controller Footpedal - (circuit / schematic design added 6/06)

Miniature high-rate speed control - A miniature high-rate speed control published in the newsletter published by Electric Model Flyers' of Southwestern Ontario (diagram add

Miniature low-rate speed control - A miniature low-rate speed control published in the newsletter published by Electric Model Flyers' of Southwestern Ontario (diagram added 10/06)

Minimize the Short Circuit Current Pulse in a Hot Swap Controller - 05/27/04, EDN-Design Ideas: Because of internal circuit-breaker delay and limited MOS-gate pulldown current, many hot-swap controllers do not limit current during the first 10 to 50 microseconds following a shorted output. The result can be a brief flow of several hundred amperes. A simple external circuit can counter this problem.....(design idea added 02/05)

Modulated Constant Off-Time Control Mechanism AN-9 - Application Note 9 from Microsem (app note added 6/06)

Monitor & TV Power Supply - (application / block diagram added 6/07)

MOSFET Switch Provides Efficient AC/DC Conversion - 02/17/00, EDN-Design Ideas: / (schematic / circuit added 11/03)

Motor Brake - This circuit will bring a fast moving DC motor to a stop in seconds. The braking action is automatically applied whenever DC power is removed. (added 12/04) ….(designed by David A. Johnson)

Motor Control Scheme Yields Four Positions with Two Outputs - 05/07/02, EDN-Design Ideas: Figure 1 showshow to position a mechanical device into four discrete positions but with only two free outputs and one free input from the control system. The position depends on a set of cams and four corresponding limit switches. The 24V-dc motor comes with a worm gear. Darlington transistors.....(design idea added 1/05)

Motor Control Sensor Feedback Circuits - Microchip Application Note Published 31-Dec-03 (app note added 2/06)

Motor Reversing Circuit - (electronic design added 6/07)

Motor Speed Control (Randy Linscott) - This circuit will allow you to control the speed of an AC motor, for example an electric drill. The way that this circuit works is as follows. The bridge rectifier produces dc voltage from the 120vac line. A portion on this current passes through the 10K ohm pot. The ….(added 4/05)

Motor Speed Controllers - (electronic circuit added 4/05)

Motorized Video Camera Mount - (electronic circuit added 05/07)

Multidisplay LED Controller - Linear Technology LTC3205 (app note added 2/05)

No-Hum Fan Controller - (diagram added 2/07)

Noise Filtering and the ADT7461 - AN-699 Analog Devices Application Note (app note added 2/06)

Nokia 7650 LCD Controller - Despite nobody seems to own the appropriate documentation, it is possible to use the big cheap color LCD displays of the Nokia series 60 cell phones for home brew projects. I don't even have the docs and it was a rough and painful way, but now it works.….(circuit design added 06/09)

Novel Circuit Controls AC Power - 01/07/99, EDN-Design Ideas: [Note: File contains multiple circuits scroll to find this circuit] The simple and inexpensive power-control circuit in Figure 1 uses a readily available fan regulator with built-in phase control. Such fan regulators are limited to approximately 100W. The circuit in Figure 1 adds two SCRs and a few components.....(design idea added 08/05)

On/Off Motor Control with Brake - Modern electronic speed controllers (ESCs) are very efficient, but they still have some drawbacks. An inexpensive ESC with two IRFZ40 MOSFETs has an on-resistance of 14 milliOhm. At 20A current, this means a voltage drop of 0.28V, and a power loss of 5.6W. Furthermore, to build an ESC with a brake generally requires an expensive P-channel MOSFET... (schematic added 6/07)

Opto-coupled Servo Actuator - (Schematic / Circuit added 10/06)

OptoElectronic position Control simplifies motor movements - 04/29/04, EDN-Design Ideas: The optoelectronic technique for achieving position control provides an inexpensive, easyto-design method of achieving simple, repeatable movement using fixed index points with linearor rotary-motion components. The simple, basic design in.....(design idea added 1/05)

OTP µC Controls Boomer Amplifier - 03/18/99, EDN-Design Ideas: PDF contains multiple circuits - scroll to find this circuit.....(design idea added 5/03)

Control Circuits: #-B C D-G H-I J-O P-Q R S T U-V W-Z