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
Powerlabs Flyback Driver - This is by far the best project for someone who is already familiar with High Voltage, but wants to take their experiments to the next level: It requires very little previous experience and skills with soldering and identifying components, and there are virtually no adjustments to be made. The danger is minimal, as fly back transformers are intrinsically low power devices, not capable of outputting lethal currents (due to the hair-thin secondary windings) , and yet it will give a careless experimenter a nasty RF burn if he accidentally touches the HV wire (nothing beats learning from your mistakes) . If you have never experimented with HV before though, I recommend you start off with an electrostatic project. This circuit is not a toy! __ Designed by Sam Barros
Power-Saving Relay Driver - In many circuits, the switching action is performed by a relay, which in turn activates an external load. The power consumed by the relay may be unsuitable for battery-powered applications. Here...__ Electronics Projects for You
Precision Wideband Current Probe for LCD Backlight Measurement - DN101 Design Notes__ Linear Technology/Analog Devices
Press & Hold Latching Circuit - A Discover Circuits visitor needed a latch circuit which could operate using a power supply voltage ranging from 3v to 24v. He wanted to use a tiny pushbutton switch to turn on and off power to a load. However, he wanted a 2 second delay between the switch activation and the state change of the output . . . Hobby Circuit designed by David Johnson P.E.-June, 2013
Programable LCD counter with memory backup - This counter based on AT90S1200A its programmable and when shut it down its keeping the current counts to the memory, until to the power on. __ Designed by © Vassilis Serasidis
Provide Effective LCD Drive - 09/28/00 EDN-Design Ideas LCDs find wide use in portable instruments, thanks to their attractive display and low power consumption. The circuit in Figure 1 is an effective driver for LCDs. The circuit comprises two main sections—the ICM7211 drivers (IC2 Design by Luo Ben Cheng, Chinese Academy of Science, Beijing, China
Pulsing Charge Pump Drives Capacitive Loads - 11/05/98 EDN-Design Ideas - (Several circuits here, scroll to find this one) The test circuit in Figure 1 efficiently drives various capacitive loads, such as memory cells and simple capacitors, so that you can observe their leakage effects. Essentially, the circuit is a pulsed and variable current source acting as a charge pump. A pulsed voltage source drives a one-shot oscillator Design by Paul J Rose, Mental Automation Inc, Bellevue, WA
Push-Pull Complementary Power MOSFET Driver - Circuit Ideas for Designers App Note__ Advanced Linear Devices, Inc
Push-pull driver provides isolated 5V at 1A - 03-Mar-00 EDN-Design Ideas The circuit in Figure 1 converts a regulated 5V input to an isolated 5V output with 1A current-output capability. IC1, a pushpull transformer driver, powers a pair of cross-coupled power MOSFETs in a flipflop-like configuration. InNote PDF contains several circuits, scroll to find this one. Design by Ron Young, Maxim Integrated Products, Sunnyvale, CA
Put Your Own Smiley On GLCD - The regular 16×2 LCD can display characters of only certain dimensions. A graphical LCD (GLCD) , on the other hand, can display custom graphics. GLCDs are therefore highly suitable for mobile and...__ Electronics Projects for You
PWM IC makes synchronous gate driver - 02/02/99 EDN-Design Ideas (contains several designs, scroll to find this one) A system with a µP, memory, and peripherals usually requires several power-supply voltages. Designers typically use local switching regulators to produce the desired voltage rails. One of the most common topologies, the synchronous buck regulator, converts a 5 or 12V bus to some other, lower voltage. Design by Dimitry Goder, Switch Power Inc, Campbell, CA
Quad Output Switching Converter Provides Power for Large TFT LCD Panels - DN349 Design Notes __ Linear Technology/Analog Devices
R/C Model Aircraft Marker Light Flasher (ATTINY12 & others) - The lightest weight solution I could come up with, uses just about any AVR controller. You can even do it with a PIC! __ Designed by Dick Cappels
Really Loud Output Beeper Circuit - I you need a real loud beeper, this circuit delivers about 110db (12 inches away) from a 9v battery using a single inexpensive C-MOS IC. An off-the-shelf piezoelectric beeping device is driven at resonance to insure maximum efficiency. By changing the control IC to a 74AC14, the same circuit can operate from 3v and 1.5v batteries . . . Hobby Circuit designed by Dave Johnson P.E.-June, 2000
Reduce IGBT drive cost & space - EDN-Design Ideas 06/11/2014 Use an application-specific optocoupler for an elegant solution to IGBT drive and monitoring Design by Avago Tech Note
Relay Driver - A relay is an electro-magnetic switch which is useful if you want to use a low voltage circuit to switch on and off a light bulb (or anything else) connected to the 220v mains supply. The diagram below shows a typical relay (with "normally-open" contacts) . __ Designed by © David Hoult
Relay driver saves substantial power - EDN-Design Ideas July 2, 1998 NOTE
: File has multiple design, scroll for this one. It is common practice to operate relays and solenoids at a reduced holding power once the mechanical actuation takes place. Relays are usually specified to pull in within 3 msec at 80% of the rated voltage and to release at 30% of the rated voltage. The circuit in Figure 1 drives as many as eight 12V (Ž120V coil) power relays, which memory-map into an 8-bit mP bus. An octal latch stores the relay status, where each bit of the 8-bit word serves a separate relay (0=off, 1=on) . The latch's Select line latches data on the rising edge. Whenever the relay's status data changes, the relay's drive voltage rises to the full 12V for 140 msec to ensure that the relay pulls in. A series zener diode then reduces the relay's drive voltage by 50% to reduce dissipation. Design by Tim Herklots, Maxim Integrated Products, Southamption, UK
Relay Driver Switches Two Relays with One Pin - 03/03/11 EDN-Design Ideas Logic 1, logic 0, and high-Z make for three possible states: forward, reverse, and off. Design by Gunther Kraut, PhD, Egmating, Germany
Relay driver, transistorised - This is simple transistorised relay into which can be plugged 'personality modules' to turn the base unit into a timer (pulse, delay on energise or delay on de-energise) or a latching relay or whatever is required. This is therefore a universal relay system. It was designed to simplify industrial machinery control. __ Designed by Richard Torrens
Relay logic: Start/Stop buttons - This is a way of implementing a Start and Stop button system suitable for use with 4QD controllers. __ Designed by Richard Torrens
Remote Relay Driver - I received a call from a Discover Circuits visitor who wanted a simple way to turn on an outside lighting system using a low voltage control line. I suggested the simple circuit below. The circuit is powered by a 9v battery and uses a very efficient latching relay. Two low voltage wires lead from the a toggle switch to the remote relay. A toggle switch selects either the on or off condition of the relay. The relay contacts are rated at 10 amps, so the small relay can handle a sizeable amount of power.. . . Circuit by David A. Johnson P.E.-April, 2014
Rolled-Off Noise Source - This is a circuit that generates white noise, rolled-off to drive earphones or a small speaker. White noise creates is a "rushing" sound, which sounds something like air rushing by your ear (s) . White noise would be flat with frequency, and since this circuit rolls off within the audio range, I refer to it as "rolled-off" noise. White (or rolled-off) noise __ Designed by Dick Cappels
RS232c Line Driver IC Drives Power MOSFETs - 10/24/96 EDN-Design Ideas Easy to effect an interface between power MOSFETs and TTL circuits. Design by Santosh Shetty, NCRA, Pune University, Pune, India
RS422 Converter for Minilogger - Build a simple line driver/reciever that meets RS422A for the MiniLogger V1.0. Place a distant Minilogger and communicate over a full duplex serial line. __ Designed by Wichit Sirichote
RTTY Terminal unit - This circuit may be connected directly across your rig speaker terminal and used to drive a teleprinter coil directly. A normal teleprinter coil requires 80/80 volts to energise the coil, but this is connected in series with a 2.7K resistor to give a sort of constant current. The teleprinter coil never has more than 20 volts accross it, __ Designed by Harry Lythall-SM0VPO
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