|
Pot Adjusts LCD's Contrast- 02/04/99 EDN Design Ideas: NOTE: Page includes several designs. Scroll to find this one. You can use a digitally controlled potentiometer for many purposes. In this example, you can use the device to regulate the contrast of a standard (such as two lines by 40 characters] LCD. You can use the circuit in Figure 1 in a portable test system, in which you need to change the contrast of the LCD as a function of the viewing angle. You choose the contrast setup Design by Jef Collin, CSE Systems, Turnhout, Belgium
Pot Controlled Variable LED Intensity Circuit- The circuit below uses power from four rechargeable AA NiMH
cells to drive 3 white LEDs. A potentiometer varies the duty cycle of a pulse width modulator circuit to vary the intensity of the LEDs from 0% to 100%. The beauty of the circuit is that when the. . . Circuit by David Johnson P.E.-September, 2009
Potentiometer Autonulls OpAmp- 10/22/98 EDN Design Ideas: Op-amp applications that need the highest possible dc accuracy are generally best served by CMOS
chopper-stabilized amplifiers, such as the LTC1050. But high-speed, low-noise applications may require high-performance rockets, such as the 700-MHz LT1226. So what to do for applications Design by Stephen Woodward, University Of North Carolina, Chapel Hill, NC
Potentiometer Calibrates Photodiode Amplifier- EDN-Design Ideas -- 06/09/11 Control a potentiometer IC to adjust amplifier gain, compensating for optocoupler output variations. Design by Michael J Gambuzza, General Electric Energy, Billerica, MA
Potentiometer Controls LCD Bias- 03/17/94 EDN Design Ideas: Designers of pen-based computers can easily relegate some controls that were previously mechanical, such as switches and potentiometers, to on-screen icons. For example, the circuit in Fig 1 shows one way that digital logic can control the -24V-dc LCD bias using two general-purpose I/O command lines. The DS-1669 from Dallas Semiconductor Design by Michael Cortopassi, Dauphin Technology, Lombard, IL
Potentiometer controls phase shift- 02/15/96 EDN Design Ideas: You can use dual, quad, or hex potentiometers to put all phase-shift sections under control of a microprocessor, as in Figure 2. The DS1806 hex digital . Design by Rick Downs, Dallas Semiconductor Dallas, TX
Potentiometer Model- (spice design) __ Designed by Rick
Potentiometer Programs & Stabilizes Voltage Reference- 05/30/02 EDN Design Ideas: The potentiometer portion of a mixed-signal, digitally programmable potentiometer adds variability to an analog circuit, and its controls provide programmability. You can use a potentiometer in two ways in an analog circuit. You can use it as a two-terminal variable resistance, or rheostat, or as a three-terminal resistive divider. / (schematic / circuit added 11/03] Design by Chuck Wojslaw, Catalyst Semiconductor, Sunnyvale, CA - May 30, 2002
Potentiometer tames current-feedback op Amp- 05/11/00 EDN Design Ideas: The circuit in Figure 1a includes a potentiometer in series with the inverting input of a current-feedback op amp. With a voltage-feedback op amp, Design by Leslie Green, Gould-Nicolet Technologies, Ilford, Essex, UK
Potentiometers Enable Programmable Biquadratic Filter- 07/22/04 EDN Design Ideas: Of the many types of analog filters available to designers, few allow easy adjustments of the filter parameters. The biquadratic, or biquad, filter is an exception, however. You can change that filter's corner frequency (ω0], Q, and gain (H] by adjusting the values of three resistors. For that purpose, the lowpass biquad circuit of Figure 1 includes three digital potentiometers configure Design by Deborah Mancuso and Donald Schelle, Maxim Integrated Products, Sunnyvale, CA
Programmable oscillator uses digital potentiometers- 03/07/02 EDN Design Ideas: Digital potentiometers are versatile devices; you can use them in many filtering and waveform-generation applications. This design idea describes an oscillator in which setting the resistance of two digital potentiometers independently programs the oscillation amplitude and frequency. Figure 1 shows a typical diode-stabilized Wien-bridge oscillator that generates accurate sine waves fro Design by Alan Li, Analog Devices, San Jose, CA
Pushbutton switch controls power supply & µC- 09/25/97 EDN Design Ideas: Switching handheld units on and off with a pushbutton switch is a desirable feature. Thus, switching-regulator/ controller ICs for battery-powered applications provide a logic input to switch the device to a shutdown mode. This type of shutdown pin can require additional components Design by Stephen Woodward, University of North Carolina, Chapel Hill, NC
Pushbuttons & digital potentiometer control boost converter- 02/17/05 EDN Design Ideas: Digitally controlled potentiometers are useful for generating analog control voltages under the control of a microcontroller. In some applications, manual pushbutton switches could replace a microcontroller and simplify product design. Mechanical switches exhibit contact bounce, and, when a user actuates them, they may open and close many times before reaching a stable state Design by Simon Bramble, Maxim Integrated Products Inc, Wokingham, UK
Read Multiple Switches & a Potentiometer Setting with One Microcontroller Input Pin- 04/22/10 EDN Design Ideas: Use a single ADC input pin to sense pushbuttons as well as a potentiometer. Design by Kevin Fodor, Palatine, IL
Recycle precision potentiometers as useful voltage sources- 7-Jun-07 EDN Design Ideas: A handful of precision op amps and comparators recycles precision potentiometers as handy "volt boxes. " Design by Mark Thoren, Linear Technology, Milpitas, CA
Replace a rotary switch with a potentiometer- EDN Design Ideas: 04/07/2014 Why use an expensive rotary switch with your microcontroller when you can use a cheap pot instead? Design by Claude Haridge
Rotary Encoder Mates with Digital Potentiometer- 6-Mar-03 EDN Design Ideas: Buck IC boosts battery voltage for white LED - In developing electronic systems, designers look for products or ideas that may benefit from the better performance, smaller size, lower cost, and improved reliability that an IC can offer. Toward that end, the digital potentiometer emerged as an alternative to its mechanical counterpart, the mechanical potentiometer Design by Peter Khairolomour, Analog Devices, San Jose, CA
Single switch controls digital potentiometer- 02/27/02 EDN Design Ideas: The control of electronic potentiometers in most today's applications comes from controller-generated signals. However, a significant number of applications exist that require adjustments using manual, front-panel controls. The circuit in Figure 1 uses one IC, one switch, and 10 discrete components Design by Chuck Wojslaw and Gary M Craig, Catalyst Semiconductor, Sunnyvale, CA
Single-sideband Demodulator covers the HF band- 10/26/00 EDN Design Ideas: The circuit in Figure 1 complements a previous Design Idea (SSB modulator covers HF band EDN , Sept 30, 1999, pg 122]. The modulator employs a phasing. Design by Israel Schleicher, Bakersfield, CA
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
Software Implements Digital Potentiometer- 06/08/95 EDN Design Ideas: In some applications (for example, dynamic biasing of laser diodes) , the use of digital potentiometers, or trimDACs, has limitations because of resolution, accuracy, or interface difficulties. Using the simple (but maybe not so obv Design by Gray Creager, Xicor Inc, Milpitas, CA
Stereo Potentiometer- in PDF format, text in Finnish__
Switch controls digital potentiometer- 02/27/02 EDN Design Ideas: The control of electronic potentiometers in most today's applications comes from controller-generated signals. However, a significant number of applications exist that require adjustments using manual, front-panel controls. The circuit in Figure 1 uses one IC, one switch, and 10 discrete components Design by Chuck Wojslaw and Gary M Craig, Catalyst Semiconductor, Sunnyvale, CA
Tack a log taper onto a digital potentiometer- 01/20/00 EDN Design Ideas: It's sometimes convenient to have digital control of the volume level in an audio system. The use of multiplying DACs (MDACs) is problematic because of the switching noise of the ladder network. This noise comes from the bit switches injecting charge into the signal when they turn on and off. Audio Design by Hank Zumbahlen, Analog Devices, Campbell, CA
Ten Turn Pot Forms Frequency Readout- Let’s say you are designing a signal generator for a test fixture. To adjust the frequency you would like to use a ten turn pot with a nice dial mechanism attached as a frequency display. However, a display range of 0 to 9.99 would be impractical since . . . Hobby Circuit designed by David A. Johnson P.E.-January, 2008
The experimenter’s pot-Digital Potentiometer- The experimenter's pot is a solid state potentiometer using Dallas semiconductor’s DS1869 and National’s LM78L05 two electrolytic capacitor two small push button switch and two optional Molex connector. this project is very useful especially in finding the right value of resistor in your experiments __ Contact IQ Technologies
Use a Photoelectric-FET Optocoupler as a Linear Voltage-Controlled Potentiometer- 01/19/12 EDN Design Ideas: The circuit takes advantage of an identical photo-FET as a feedback element. You can use a photoelectric FET as a variable resistor or a potentiometer in combination with a fixed resistor. The H11F3M photoelectric FET has an isolation voltage of 7.5 kV, enabling you to safely control high voltage circuit parameters. The nonlinear-transfer characteristics of these devices are problematic, however (Figure 1). To correct the nonlinearity, using a simple feedback mechanism as a potentiometer yields a linear response (Figure 2). This circuit uses two photoelectric FETs—one for feedback and the other for applications requiring an isolated potentiometer. You connect the inputs of the two photoelectric FETs in series to ensure the same amount of current for the input LEDs. Design by Sajjad Haidar, University of British Columbia, Vancouver, BC, Canada
Voltage Reference Stabilizes Current Sink- 18-Feb-10 EDN Design Ideas: Produce a stable current for long-term component testing - Analog circuits for long-term testing of passive components, such as 0.1%-tolerant resistors or high-intensity white LEDs, often require a constant current. Using two op amps and a voltage reference, you can develop a circuit that provide as a constant-current sink with a variable setting of 0 mA to 0.99A. The circuit in Figure 1 sinks a stable current through the load. The load current is insensitive to power-supply-voltage variations. Design by Suded Emmanuel, Emmanuel’s Controls, Auckland, New Zealand
Voltage Regulator goes Digital- 11/24/99 EDN Design Ideas: Power consumption and failing batteries are key issues in battery-operated applications. Features in the new generation of series voltage regulators address these concerns. For example, National Semiconductor's LP2951 micropower voltage regulator provide as a logic-level output signal indicating a low regulated Design by Chuck Wojslaw, Xicor Inc, Milpitas, CA
Volume Control- This digital volume control has no pot to wear out and introduces almost no noise in the circuit. Instead, the volume is controlled by pressing UP and DOWN buttons. This simple circuit would be a great touch to any home audio project. __ Designed by Aaron Cake
Volume Control has Log Taper- 04/11/02 EDN Design Ideas: Digital potentiometers provide a compact and convenient way to attenuate audio-amplifier signals. However, most such potentiometers suffer from at least one flaw a nonlogarithmic step increment. To avoid this problem, a user must usually step the potentiometer in a nonlinear sequence to simulate a logarithmic taper Design by Doug Farrar, Los Altos, CA
Where is the wiper?- 08/08/02 EDN Design Ideas: You enjoy significant advantages when using DPPs (digitally programmable potentiometers] with increment/decrement serial interfaces. Programming the serial interface is simple and fast, and you can adjust the potentiometer in real-time applications. The interface, however, provide as no information about wiper position, and this information is important in some applications Design by Chuck Wojslaw and Dave Gillooly, Catalyst Semiconductor, Sunnyvale, CA |
