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Tricolor LEDs Create a Flashing Array - 24-Jun-10 EDN-Design Ideas You can build a matrix of RGB(red/green/blue) LEDs using a simple and inexpensive circuit comprising the control logic and driver circuit in Figure 1 and some LEDs(Figure 2). The center RGB LED is the first to come on, after which each sequential LED in the 8×8-LED matrix follows. This process gives the appearance that the display is alive and moving outward. This sequence repeats, producing a rainbow effect of colors Design by Jeff Tregre, www/BuildingUltimateModels/com, Dallas, TX
Triple Stroboscope - This circuit enables observation of movement between other stroboscopes. Generation of rectangular signal is based on NE555. This circuit requires a low power supply that is made from a simple transformer TR1, traditional rectifier bridge and zener diode. NE555 works in multivibrator mode generating astable pulses of 2Hz to 20Hz. The frequency is adjusted by potentiometer P1. The control potentiometer P1 can be placed as far as 30 meters away, for suspension of stroboscope’s work from far away. __ Contact: IQ Technologies
Triple-Mode Tone Generator - Here is a simple circuit that generates three different tones. You can use it as a call bell, burglar alarm or any other security alarm.Fig.1 shows the circuit of the...__ Electronics Projects for You
Tube provides linear tuning - 11/05/98 EDN-Design Ideas (File has many circuits, scroll to this one) Parallel LC circuits that you tune by changing capacitance have a nonlinear frequency-versus-voltage or frequency-versus-shaft-position characteristic. The frequency of an analog-tuned circuit is proportional to the reciprocal of the square root of the tuning capacitance. When you tune a bandwidth that is say, 5% or less of the center frequency, the frequency-versus-capacitance Design by Lyle Williams, Electronic Technical Services, New Orleans, LA
Turn on the aquarium lights every day at the same time - This is a simple one-valve irrigation controller made for our greenhouse. The code contains a software real-time clock (RTC) and a multiplexed 8-digit LED display and keyboard you can use in other projects. Turn on the sprinkler or the aquarium lighting for the same period of the day. You can choose to operate the output by every 2nd, 3rd day only. There is a manual start/stop button to immediately turn on or off the output, and a disable button to completely turn off automatic operation __ Designed by Peter Jakab
Turn-signal System for Motorcycles - This circuit is based on the CMOS
IC from Motorola, the MC14049UB Hex Inverting Buffer. Of course, the regular CD4049 can be used and is pin-for-pin compatible. The 4049 is a 16-pin chip. Maximum DC supply voltage should not exceed 18V. The above diagram can replace your existing mechanical clicker. The prototype worked excellently!__ Tony van Roon VA3AVR
TV /VCR Remote Range Extender Circuit - I often get frustrated by how poor some infrared remotes in many new electronic devices operate. I used to be able to turn on the TV from 30 feet away. Now, it seems that I have to get within 15 feet. To address this issue, I designed the circuit shown below. The circuit taps into the TV remote’s existing infrared LED and drives 8 more efficient devices. The result is a communications range some 4 to 5 times longer.. . . Circuit by David A. Johnson P.E.-October, 2005
TV Light - Switch you TV lamp while comfortably seated on you armchair, using your TV's remote control (*). Of course, you can use the same circuit for a variety of other "comfortable" uses, like controllin a fan or the heating. Those very versed in electronics DIY could apply it to very unusual devices, like telephones or answering machines. __ Designed by Projects & Ideas from Nutchip.com
TV Remote Control Jammer - Scroll to this oneDo you have an incessant channel hopper that is driving you crazy? Or perhaps you simply want to enforce your own selections. The TV Remote Control Jammer will do the trick. This circuit is a redo of an older design which is not effective on modern remotes. Modern remote controls are hard to jam but with a little care this circuit will do the job. The circuit is just a flasher operating at 40 kHz which is the carrier frequency used by common remote controls. The strong 40 kHz infrared flashing interferes with the signal from the remote.
__ Contact: Charles Wenzel of Wenzel Associates, Inc.
TV-VCR Light Source 40Khz Repeater - This circuit is designed to be placed directly in front of a standard TV or VCR remote. The exiting light pulses produced by the circuit match the pulses from the remote but are about 10 times more powerful . . . Hobby Circuit designed by David Johnson P.E.-June, 2000
Twinkle Twinkle X’mas Star - Christmas just would not be Christmas if you do not put a flashing star on your Christmas tree. Here is the circuit of such a flashing star.Fig.1 shows the circuit...__ Electronics Projects for You
Two Basic Motor Speed Controllers - Here are two simple 12V DC motor speed controllers that can be built for just a few dollars. They exploit the fact that the rotational speed of a DC motor is directly proportional to the mean value of its supply voltage. The first circuit shows how variable voltage speed control can be obtained via a
Two Components Drive Stepper Motor - EDN-Design Ideas 01/19/95 The extremely simple circuit in Fig 1 drives a stepper motor directly from 120V ac, 60 Hz. Usually you need switched-dc voltages to drive a stepper motor. But a stepper motor will run off ac lines if you introduce a 90° phase shift between the voltages applied to the motor's two windings. Design by Carl Spearow, Basler Electric,m Highland, IL
Two Light Controlled Relays - Switching Circuits: These two circuits use LDRs (Light Dependent Resistors). Circuit No.1 energizes the relay when the light rises above a preset level. Use it to switch things on at dawn. Circuit No.2 energizes the relay when the light falls below a preset level. Use it to switch things on at dusk. __ Designed by Ron J.
Two Load-Sharing, Redundant, 48V/10A Power Supplies using an Ideal Diode - This circuit shows a 48V/10A ideal diode-OR application. An MBR10100 Schottky diode would dissipate 6W under these operating conditions. In contrast, the FDB3632 7.5mohm MOSFET dissipates only 0.75W. The reduced power loss increases efficiency and saves space required for heat sinking. If the power supply voltages are nearly__ Linear Technology/Analog Devices App Note, Jul 8th 2011
Two Pushbutton Motor Controller - Two small pushbutton switches, a few diodes and two relays form a method to control on/off power to a brush motor as well as the motor direction. The circuit was originally designed for a motorized lifting platform. . . Circuit by David Johnson P.E.-September, 2005
Two Signals Easily Control Tricolor LED - 09/14/95 EDN-Design Ideas Tricolor LEDs come in two- and three-pin packages. Although the three-pin, or common-cathode, package easily lends itself to 2-bit control, wiring three crowded pins can be mechanically difficult. Also, fewer manufacturers produce the three-pin types. The two-pin package is easier to connect to a wiring harness and is readily available. However, this package requires more control overhead, because, to light the LED yellow, the device must continuously alternate between red and green. Design by Bob Richards, Digital Audio Corp, Raleigh, NC
Two Temperature Controlled Relays - Switching Circuits: These two circuits use Thermistors (Temperature Dependent Resistors). Circuit No.1 energizes the relay when the temperature rises above a preset level. Use it to switch things on when it gets hot. Circuit No.2 energizes the relay when the temperature falls below a preset level. Use it to switch things on when it gets cold. __ Designed by Ron J.
Two Tone Generator - This two-tone generator includes 3 ICs NE555 Astable Multivibrators. You can vary the duration of each tone by changing the 10k resistor or 100MF capacitor at IC1 or changing resistors and capacitors at IC1/2 for higher or lower tone. __ Designed by Andrew R. Morris
Two tone mixer IIP3 Notes - As a measuring experimenter with a homebrew POV, I like to add new test equipment and procedures to my lab each year. With digitally processed spectrum analyzers getting more able and relatively cheaper over time, I think a spectrum analyzer (with a built in tracking generator) might prove one of the best toys to consider buying. As ever, a homebrew SA remains a valid option for more advanced builders. __ Contact: Vasily Ivanenko
Two Transistor Flasher - The basic two-transistor flasher shown below has found its way into dozens of applications due to its simplicity and versatility. Applications have included such diverse circuits as a micropower low battery indicator, a lightning detector, a off-line. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Two Transistor LED Flasher - This circuit will flash a bright red LED as an attention getting device or fake care alarm. __ Designed by Bill Bowden
Two Transistor LED Flasher - This is a classic 2 transistor astable multivibrator. Many other NPN small signal or switching transistors can be used, including 2N4401, PN2222 or 2N2222 using the circuit on the left. The circuit can also be inverted using PNP transistors such as 2N3906, 2N4403, PN2907, or 2N2907 as shown to the right __ Designed by Bill's Electronics Reference Library
Two Transistor LED Flasher 1 - Circuit Only __ Designed by Tony van Roon VA3AVR
Two Transistor LED Flasher 2 - This circuit will flash a super-bright LED (5000+ mcd). Good for fake car alarm or other attention getting device. Component values are not critical, try anything else first from your junkbox. Obviously, the 470 ohm resistor (R3) determines the LED's brightness and limits the current flow to about 20mA.390 ohm can also be used as a save value. If you decide to go with a green or yellow led, which draw more current, you may want to replace the 470 ohm with an appropriate value. Flash rate is determined by R2 and C1 __ Designed by Tony van Roon VA3AVR
Two transistor lights LEDs - 04/09/09 EDN-Design Ideas A previous Design Ideasdescribes a circuit that uses an astable multivibrator to drive an LED (Reference 1]. The circuit in Figure 1 uses a simpler alternative approach. The circuit uses a 2N3904 NPN transistor and a 2N3906 PNP trans Design by Barry A Tigner, Michigan State University, East Lansing, MI
Two Watt Amplifier - A 2 Watt audio amplifier made from discrete components. This was one of the earliest circuits that I ever designed and built, in Spring 1982. At that time I had only an analogue meter and a calculator to work with. Although not perfect, this amplifier does have a wide frequency response, low harmonic distortion about 3%, __ Designed by Andy Collison
Two Watt Amplifier - An audio amplifier made from discrete components with 2 Watts audio power into an 8 ohm load. Carlos has used this amplifier on his AM radio for many years. __ Designed by Carlos Feldman
Two Wire Stepper Motor Positioner - A simple and inexpensive way to remotely rotate a display or object is with a positioner that uses a stepper motor to rotate it. The motor is driven by a circuit mounted near the motor and by a control circuit at a remote location. __ Golab.com
Two-button control for dangerous machines - Two button control systems are used on dangerous industrial machines in order to protect the operator’s hands. Just for hobby I made a circuit that turns on a relay by pressing two buttons simultaneously. __ Designed by Andrea-Central Italy
Two-Chips Simplify Layout for High-End Embedded Control - 04/01/99 EDN-Design Ideas NOTE
: File contains many designs. Scroll to this one. If you are considering using one of the 32- or 64-bit RISC µPs from Integrated Device Technology (IDT], the company’s new RC32134 and RC64145 system-controller ICs (Picture] can make your job easier. The chips provide synchronous-DRAM, memory, and I/O control; a PCI interface; and peripherals, including UARTs, timers, and interrupt controllers. The 32134 for the RC32364 µP provIdeas a glueless interface to DRAM Page includes
several designs. Design by Graham Prophet
Two-wire DC Lamp Dimmer replaces Rheostats - 10/23/97 EDN-Design Ideas Originally for use in commercial trucks, a low-cost dc lamp dimmer (Figure 1) can control more than 100W of incandescent panel lighting and replaces a high-power rheostat, whose heating darkensinstrument panel. Design by Kevan O'Meara, KO Systems, Chatsworth, CA
Two-wire Lamp Flasher - This circuit was designed to provide that continuous light lamps already wired into a circuit, become flashing. Simply insert the circuit between existing lamp and negative supply. __ Contact: Flavio Dellepiane, fladello @ tin.it
Two-wire remote sensor preamp - 01/13/14 EDN-Design Ideas Locally condition and amplify a distant sensor using only a two-wire connection for both power and signalThis Design Idea implements a remote sensor preamp (e.g., for a piezoelectric transducer) which transfers both signal and power over a single wire pair or coax Design by Vladimir Rentyuk
Type 1 Solar Engine-voltage controlled trigger - Voltage controlled triggerThis is by far the predominant form of solar engine, since they are "efficient enough" for most uses, and pretty simple to build. __ Contact: Eric Seale
Type 2-Solar Engine-time controlled trigger - Time controlled triggerThese aren't terribly efficient, but are handy for 'bots that need activity at specific times. __ Contact: Eric Seale
Type 3-Solar Engine-charge curve differentiated - Charge curve differentiated (i. e. , it triggers when the charge rate of the capacitors slow down) -- These are theoretically the most efficient, though type 3 designs are still in their infancy. __ Contact: Eric Seale
Typical Strobe Light Trigger - 555 based Timing circuit which triggers a SCR which controls the trigger transformer __ Designed by Don Klipstein
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