Electronics and Communication Projects (ECE)- IX

32 Bit Serial Receiver (57.6 K Baud TTL and CMOS): (electronic schematic / circuit added 11/05)



51 MHz Frequency Counter Voltage Meter and SwR/PWR Indicator: (electronic Circuit diagram added 02/07)


68HC11 Instruction Halts External RC Clock: 04/27/95 EDN-Design Ideas / (added 3/03)


8 Hints for Debugging Microcontroller Based Design: Agilent Application Note (app note added 6/06)


8 Hints for Debugging Siemens MCU-based Designs: Agilent Application Note (added 6/06)


8051 Development System Circuit Board #2: (electronic circuit added 4/05)


9 Second Digital Readout Timer: (circuit / schematic design added 6/06)


µP Displays 10 Bit Data on Three LEDs: 11/07/96 EDN-Design Ideas / (added 08/05) circuit in Figure 1 uses a PIC16C55 µP to read 10-bit binary data and directly display data in decimal format on three common-cathode LED displays. If value of data exceeds 999, displays show three hyphens (---) to represent overflow. PIC16C55 has high drive capability. Each output pin can source 20 mA and sink 25 mA; outputs can thus directly drive LED display


9 Second Digital Readout Countdown Timer: This circuit provides a visual 9 second delay using a 7 segment digital readout LED. When the switch is closed, the CD4010 up/down counter is preset to 9 and the 555 timer is disabled with the output.... (added 3/07)


9 Second Digital Readout Timer: (circuit added 7/02)


Animated LED Signboard (PIC16C84): (electronic circuit added 4/05)


Connecting AT90S2313 with LCD Display 2x16 Char and 4x4 Keypad: (electronic circuit added 4/05)


Interfacing 16x2 Character LCD to Parallel Port: (circuit added 7/02)

µC implements Pushbutton Light Dimmers: 06/18/98 EDN-Design Ideas / (added 08/05) A project required building a synchronous-demodulator circuit to track a line drawn on paper. beauty of synchronous-modulator/demodulator approach is its inherent noise rejection. method rejects nearly all out-of-band noise, wher from internal drift or external illumination. This rejection is a boon in optical tracking, where return signal is inevitably buried in 120-Hz ambient light, amplifier offsets, and temperature drifts. circuit in Figure 1 is inexpensive, and it operates from 5V dc. circuit scans eight LED/sensor pairs every 22 msec and stores result in eight sample/hold (S/H) capacitors for interrogation by a µP-driven ADC. purpose of circuit is to determine which sensor is above line.

Circuit optimizes PhotoTransistor Bandwidth : 04/09/98 EDN-Design Ideas / (added 3/03)

Control Interface for Standard 0 - 10VDC Dimmers / ABR-42021: Fairchild Application Notes / (app note added 6/06)

A Ballast that can Be Dimmed from a Domestic (Phase Cut) Dimmer.: A system has now been developed, based around IR2156, where ballast is able to operate with minimal flicker over a considerable portion of adjustment range of a dimmer and light output may be controlled over this range from maximum output down to around 10%. (added 6/06)

4 Channel dimmer rack: (electronic circuit added 4/05)

8 Bit Digital Light Intensity Controller : (design circuit added 8/02)

A GPS Receiver Based Frequency Standard: (electronic circuit added 4/05)

Aisin-Seiki GPS-Receiver (Us$20 GPS): (electronic circuit added 4/05)

Alternative Power Source for Magellan GPS Receivers: (electronic circuit added 4/05)

Digital Compass Schematic: (electronic circuit added 7/03)

GPS Handheld: Intersil Application Block Diagram (app note added 6/06)

GPS Receiver Support Kit: (electronic circuit added 4/05)

Inertial Navigation System uses Silicon Sensors: 09/16/04 EDN Design Ideas / (added 1/05) A strap-down inertial-navigation system uses silicon sensors to measure displacement without entailing the bulk and expense of moving parts or GPS receivers. For example, a three-axis accelerometer and three angular-rate sensors can determine the position and velocity of a vehicle such as a robot or radio-controlled aircraft....

U-Blox GPS receiver Board: (electronic circuit added 4/05)

Ultra Low Noise Precision High Speed Op Amps: Linear Technology LT1028(app note added 02/05)

16x16 LED Matrix and Driver: (circuit added 9/04)

2 Wire LCD Interface using PIC16cf84: (schematic / circuit design added 9/02)

20 Db Amplifier and High Current Balanced Line Driver: (circuit added 7/02)

A Design and Manufacturing Guide for the Lead Frame Chip Scale Package (LFCSP): AN-772 Analog Devices Application Notes (app note added 6/06)

7 Segment Rolling Display using PC: It is very interesting and convenient to be able to control everything while sitting at your PC terminal. Here, a simple hardware circuit and software is used to interface a 7-segment based rolling display. The printer port of a PC provides a set of points with some acting as input lines and some ors as output lines. Some lines are open collector type which can be used as input lines. The circuit given here can be used for interfacing with any type of PC’s printer port. The 25-pin parallel port connector at back of a PC is a combination of three ports.. (added 10/05)

72 LED Clock: (circuit added 7/02)

Digital Step Km Counter Max.: Pedometer has a range of 9.950 meters with2-digits. Slip it in pants pocket for walking and jogging (Electronic circuit design added 02/05)


Pedometer: Pedometer has a range of 9.950 meters with2-digits. Slip it in pants pocket for walking and jogging (Electronic circuit design added 02/05)

Unusual Frequency Dividers: (electronic circuit added 7/03)

66000 Modular Power System: Agilent Application Note (app note added 6/06)

9-V Stabilized Power Supply: (added 2/06)

6 to 12 Volt Converter: This circuit can provide up to 800mA of12V power from a 6V supply. The circuit is simple, about 75% efficient and quite useful. (added 4/02)

5 to 1.8V converter works without magnetics: 04/13/00 EDN-Design Ideas / (added 11/05)

3A Point-of-Load Power Supplies - MP1570 - DN0004: Monolithic Power Systems, Inc - Design Note - (added 6/06)

1119 Simple Regulator Provides ±12 Volt from 5 Volt Source: National Semiconductor Application Note 31 Aug2001 (app note added 7/02)

12 Volt 30 Amp Power Supply: uses a single 7812 IC voltage regulator and multiple outboard pass transistors, this power supply can deliver output load currents of up to30 amps (added 6/06)

1.3V Power Supply: This is a replacement power source for 1.3V mercury cells or other small batteries. It has many uses and I use this circuit in my computer to power a front panel multi adapter which has a digital thermometer. (added 6/06)

0 to 300 Volt Adjustable Power Supply: This is a simple circuit that can provide an adjustable voltage source of0 to330 Volts. The supply is short-circuit proof: the current is limited to about100mA. (added 6/06)

+30V DC-DC converter: introduce the compact DC-DC converter in this page. I found this converter at the junk shop. I attempted to examine the characteristic of this converter. The input voltage is +5 V, the output voltage is +30 V and can get the about 20-mA output current. The IC(CD-1846P) to be using with this converter becomes the manufacturing stop already. However, TDK said that it was the discontinuation part and I could not acquire the data. Because it may become the reference when you use the similar circuit, I introduce in the contents of the converter. (app note added 4/05)

+5 to-15 Volts DC Converter: National Semiconductor - Application Note (app note added 2/06)

Ask the Applications Engineer 1-Multi Troubles: AN-354 Analog Devices Application Notes (app note added 2/06)

AN-759: Expanding the Number of DAC Outputs on the ADUC8xx and ADUC702x Families (uC012): AN-759 Analog Devices Application Notes (app note added 2/06)

12 V DC: 120 VAC Inverter Schematic: An Inverter is a device that converts 12 volts DC to 120 volts AC. , which is what we use in our homes. This project will handle about 300 watts, which is perfect for lights, small TV's and radio equipment. This Inverter takes 12 volt DC and steps it up to 120 volt AC. wattage depends on which transistors you use for Q1 and Q2, as well as "Amp Rating" of transformer you use for T1. This inverter can be constructed to supply anywhere from 1 to 1000 (1 KW) watts. If Q1, Q2 are 2N3055 NPN Transistors and T1 is a 15 A transformer, n inverter will supply about 300 watts. Larger transformers and more powerful transistors can be substituted for T1, Q1 and Q2 for more power. Note: Don't try to run inductive loads (motors...) off this inverter. (added 4/05)



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. (added 6/03)

Simple Fix Adds Door-Chime Repeater: 05/13/99 EDN-Design Ideas / (added 11/05)

Automotive Relay Drivers using the Zvn4206av: Protection Free Interfacing with Avalanche Rated MOSFETs: Zetec Semiconductors Applications Notes An alternative solution is provided to usual large package Darlington effected relay driver. The ZVN4206AV has been designed, processed and rated to withstand significant energy within breakdown region. This allows part .... (app note added 2/06)

AT89C2051 Serial Coms to LED Driver: (circuit / schematic design added 6/06)

AT89C2051/4051 Driving Dot Led: (circuit / schematic design added 6/06)

AN-H20: HVCMOS Drivers for Non-Impact Printing: Supertex Semiconductors (app note added 6/06)

AN-H44: HV832 Dual EL Lamp Driver Circuits: Supertex Semiconductors (app note added 6/06)

(AN 30) LX1995 LED Driver: Camera Flash Application: Application Note Microsemi 1313 (added 2/07)

(AN-13) LX1686 Backlight CCFL Direct Drive Design Reference: Application Note Microsemi 1401 (added 2/07)

0 to 24 DB Gain Amplifier and Balanced Line Driver : (electronic schematic / circuit added 4/02)

12 Volt DC Fluorescent Lamp Driver: This fluorescent lamp driver uses a normal 120 to 6V step-down transformer in reverse to step12V to about350-Volt to drive a lamp without need to warm filaments. (added 6/06)

128x64 LCD Driver for AT90S2313 (Zip File) : (electronic circuit added 4/05)

16x16 LED Matrix and Driver: (circuit / schematic design added 6/06)

1a Flash LED Driver : Sipex Application Note (app note added 6/06)

20 DB Amplifier and High Current Balanced Line Driver : (circuit added 7/02)

Advanced IGBT Driver Application Manual: Application Note Microsemi 1903

AN-521: Dual Tone Multiple Frequency (DTMF): National Semiconductor Application Note (app note added 2/06)

AN-666: DTMF Generation with 3.58 MHz Crystal: National Semiconductor Application Note (app note added 2/06)

DTMF Decoder for PC: Displays DTMF digits on your computer screen in real-time. (circuit added 8/06)

Radio Remote Control using DTMF #2: Here is a circuit of a remote control unit which makes use of the radio frequency signals to control various electrical appliances. This remote control unit has 4 channels which can be easily extended to 12. This circuit differs from similar circuits in view of its simplicity and a totally different concept of generating the control signals..... (added 09/05)

Simple 4-CH Remote Control: 4 channel remote control using MC145026, MC145027. (circuit added 8/06)

Radio Remote Control using DTMF: (electronic circuit added 10/05)

Synthesize Optimal Digital-Frequency Dividers: 05/13/99 EDN-Design Ideas / (added 11/05)

Precision Divide by Two Analog Attenuator Needs No External Components: 03/17/05 EDN Design Ideas / (added 11/05) Many modern A/D converters offer only a 5V input range, and using these converters with a 65V or larger input signal gives the designer a problem: how to discard half of a good analog signal without introducing errors and distortion. To solve the problem, you can use an attenuator comprising two operational amplifiers and two resistors (Figure 1).

Clock Divider: (Circuit / schematic design added 6/06)

Charge Pump Doubles Negative Voltage: Maxim Application Note #782 (Circuit / schematic design added 6/06)

Frequency Divider Adapts to I / O Conditions: 09/29/94 EDN-Design Ideas / (Electronic Circuit diagram added 03/03) CanadaThe circuit in Figure 1 accepts an input clock signal, such as from a crystal oscillator, and divides the frequency according to the input divisor word. You can easily modify the basicdesign of this versatile PLD-based ...

Make a simple PC based frequency meter: 04/29/99 EDN-Design Ideas / (added 11/05) A simple, low cost, and precision frequency meter uses only two pins of a pc parallel port (Figure 1). The TTL-level periodic input signal with frequency fIN connects to the ACK pin of LPT1. This input produces an IRQ7 hardware in- terrupt on every rising edge (Figure 2). The software counts the number of IRQ7 interrupts in the time unit of timebase T. If this timebase is 1 sec, the frequency of the input signal equals the number of IRQ7 interrupts in 1 sec....

Single Supply Operation of JFET Multiplexers: AN-32 - Analog Devices Application Notes (added 2/06)

Avoiding Passive-Component Pitfalls: AN-348 - Analog Devices Application Note (added 2/06) The Wrong Passive Component Can Derail Even the Best Op Amp or Data Converter. Here Are Some Basic Traps to Watch For.

AN-769: Generating Multiple Clock Outputs from the AD9540: AN-769 - Analog Devices Application Notes (added 2/06)

AN-35: Understanding Crosstalk in Analog Multiplexers: AN-35 - Analog Devices Application Notes (Circuit / schematic design added 6/06)

AN-345: Grounding for Low-and-High-Frequency Circuits: AN-345 - Analog Devices Application Note (Circuit / schematic design added 6/06) Know Your Ground and Signal Paths for Effective Designs. Current Flow Seeks Path of Least Impedance-Not Just Resistance....

µC Based Circuit Performs Frequency Multiplication: 05/27/99 EDN-Design Ideas / (Circuit / schematic design added 6/06)

AN-249: over Voltage Protection for the ADG5XXA Multiplexer Series: AN-249 - Analog Devices Application Notes (Circuit / schematic design added 6/06)

Circuit makes simple FSK modulator: 10/11/2001 EDN - Design Ideas / (added 11/03) The need for a compact telemetry system poses a challenge for designing a small, light, low-component-count system. Interfacing serial data from the microprocessor is also difficult because most low-cost RF transmitters do not accept dc levels at the input. Commercial FSK (frequency-shift-keying) modulators are bulky and need many passive components. .

Low Cost Programmable Oscillator Operates at 2 GHz: 05/11/00 EDN-Design Ideas / (added 7/03) All wireless communication systems need a local oscillator. Figure 1 shows a low-cost PLL circuit for the 2-GHz band for such applications as industrial, scientific, and medical (ISM) and satellite personal-communication systems (S-PCS). The central...

Voltage-To-Frequency/Frequency-To-Voltage Converter: Microchip Application Note - Published 12-Nov-02 (added 2/06)

Precision Voltage-To-Frequency Converter: AN-C: Application Note CV/F Converter ICs Handle Frequency-to-Voltage Needs, 3-Oct-02 (added 2/06)

New Phase Locked Loops: (Electronic Schematic / circuit added 4/02)

F/V Converter has High Accuracy: 05/12/94 EDN Design Ideas / (added 2/06)

Frequency-to-Voltage Converter uses Sample-and-Hold to Improve Response and Ripple: National Semiconductor - Application Note (Circuit / schematic design added 6/06)

Circuit Converts Pulse Width to Voltage #2: 10/28/99 EDN-Design Ideas / (Electronic Schematic / circuit added 4/02) -- The circuit is optimized for a positive-going pulse width of1 to2 msec, repeating at intervals of approximately17 msec. The output produces a voltage of0.95V for a1-msec pulse to2.25V for a2-msec pulse.

Function Generator #2: (electronic (schematic / circuit added 11/05)

Function Generator #4: (schematic / circuit design added 9/02)

Function Generator #5: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

Improve Function Generators with Matched D/A Converters: AN-322 Analog Devices Application Notes (app note added 6/06) AD7528 Dual 8-Bit CMOS Multiplying DAC Makes Function Generation Practical and Affordable

Using a Function/Arbitrary Waveform Generator to Generate Pulses: Agilent Application Note (added 6/06)

MAX038 Function Generator: This is a function generator that can generates 10Hz through 20MHz in six ranges. Analog output can select one of any wave forms, sine, triangle or square. TTL output can select 50% fixed duty or variable pulse width. (added 6/06)

LM2907 Tachometer/Speed Switch Building Block Applications: National Semiconductor Application Note 04-Nov-1995 (circuit added 7/02)

AN-205: Video Formats and Required Load Terminations: AN-205 Analog Devices App Notes (app note added 2/06)

Adding HART® Capability to the AD421, Loop-Powered 4 mA–20 mA DAC using the 20C15 HART Modem: AN-534 Analog Devices Application Notes (app note added 2/06)

A Digitally Programmable Gain and Attenuation Amplifier Design: AN-137 Analog Devices Application Notes (app note added 2/06)

12-Bit Voltage-Output DACs for Single-Supply 5V and 12V Systems: AN-225 Analog Devices Application Notes (app note added 2/06)

µC RePrograms Audio DAC via Serial Interface: 01/07/99 EDN-Design Ideas / (added 08/05) [Note: File contains multiple circuits scroll to find this circuit] You can use a simple µC to continuously program an audio DAC so that it operates in a 20-bit resolution mode ( Figure 1 ). After power-on, PCM1710 delta-sigma DAC (Burr-Brown Corp, www.burr-brown.com) operates in its default 16-bit resolution....

Voltage-To-Frequency/Frequency-To-Voltage Converter: Microchip Application Note Published 12-Nov-02 (app note added 2/06)

Two Diode Odd Order Multiplier: (electronic circuit added 7/03)

New Phase Locked Loops: (electronic (schematic / circuit added 4/02)

Hear Amateurs on Your FM Radio!: (electronic (schematic / circuit added 2/05)

Frequency Tripler using the Ca3028: (electronic circuit added 7/03)

Frequency Doubler Operates on Triangle Waves: 03/14/96 EDN-Design Ideas / (added 03/03)

Delay Line implements Clock Doubler: 07/18/96 EDN-Design Ideas / (added 3/03)

Circuit Converts Pulse Width to Voltage #2: 10/28/99 EDN-Design Ideas / (added 4/02) -The circuit is optimized for a positive-going pulse width of1 to2 msec, repeating at intervals of approximately17 msec. The output produces a voltage of0.95V for a1-msec pulse to2.25V for a2-msec pulse.

900MHz Down Converter Consumes Little Power: 06/22/95 EDN-Design Ideas / (added 3/03)

555 Makes Handy Voltage to time Converter: 02/01/01 EDN-Design Ideas / (added 11/05) The circuit in Figure 1 is a simple, low-cost voltage-to-time converter using ubiquitous 555 timer chip. You can use IC's monostable multivibrator as a voltage-to-time converter by connecting analog-voltage input to charging resistor, R, instead of connecting R to VCC. With this modification,....

AN-279: Using the AD650 Voltage-to-Frequency Converter as a Frequency-to-Voltage Converter: AN-279 - Analog Devices Application Notes (Circuit / schematic design added 6/06)

Circuit Converts Pulse Width to Voltage: 10/25/01 EDN Design Ideas / (added 1/05) The circuit in Figure 1 converts pulse information to a clean dc voltage by the end of a single incoming pulse. In another technique, an RC filter can convert a PWM signal to an averaged dc voltage, but this method is slow in responding. Converting low-duty-cycle pulse information is slower yet. ...

LM2907 Tachometer/Speed Switch Building Block Applications: National Semiconductor Application Note 04-Nov-1995 (circuit added 7/02)

Using the AD650 Voltage-to-Frequency Converter as a Frequency-to-Voltage Converter: AN-279 - Analog Devices Application Notes (Circuit / schematic design added 6/06)

Voltage-To-Frequency/Frequency-To-Voltage Converter: Microchip Application Note - Published 12-Nov-02 (added 2/06)

Converter ignores Power Supply Variations: 01/05/95 EDN-Design Ideas / (Electronic circuit design added 02/05)

Circuit Converts Pulse Width to Voltage #2: 10/28/99 EDN-Design Ideas / (added 1/04) -- PDF contains multiple circuits - scroll to find this circuit. --- The circuit is optimized for a positive-going pulse width of1 to2 msec, repeating at intervals of approximately17 msec. The output produces a voltage of0.95V for a1-msec pulse to2.25V for a2-msec pulse.

42 Mc Band to 88 Mc Band (Retrofit Converters): (Electronic circuit added 7/03)

RF Frequency Linear Tuning Varactors: MicroNote 705 from Microsem (Circuit / schematic design added 6/06)

CMOS inverters convert RF to digital signal: 1/5/06 EDN Design Ideas / (added 10/06) Hex-inverter-based design suits frequencies up to180 MHz.

50 MHz to 146 MHz Converter: (added 2/05)

Zero Crossing Detector: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06)


Time tag impulses with zero crossing circuit: 01/24/2002 EDN - Design Ideas / (added 11/03) A "constant-fraction discriminator" usually performs the time-tagging of impulsive events, which have a peaking time of the signal amplitude. The implementation of this technique requires a delay in the input signal of approximately the same amount as the signal's rise time. You can attain this delay by using a coaxial cable of an appropriate length.


Self Powered Sine to Square Wave Converter: Converts sine to square waves without a power-source Useful as a test instrument for audio purposes (Circuit added 9/04)


Voltage Controlled Oscillator ( VCO ): The oscillation frequency of the voltage controlled oscillator is controlled by the output of the PLL synthesizer and does the stable oscillation of 119.3 MHz. (Electronic circuit design added 02/05)

Pellistors: Pellistors employ catalytic combustion to measure combustible gases or vapors in air up to the Lower Explosive Limit (LEL)* of the gas. The standard sensor consists of a matched pair of elements, typically referred to as a detector and compensator (reference element). The detector comprises a platinum wire coil embedded within a bead of catalytic material. The compensator is similar except that the bead does not contain catalytic material and as a consequence is inert.(Electronic circuit design added 02/05)


MOSFET Current Mode Resonant Coil Driver: The schematic was made long after the circuit was built and perfected. Sorry. That means I cannot guarantee that it is free of errors. However, the schematic was compared to the original as best as I oould. ERRATTA: 1. The resistor network at pins 6 and 7 of the LM555 is incorrect. Instead of a fixed 200k and a 500k pot in parallel, it should be the 200k fixed in parallel with a 500k pot and the resulting two in series with a 1k fixed. Thus the 200k fixed established the maximum duty cycle, and the 1k pot establishes the minimum duty cycle. You could try eliminating the 1K, but you might damage the LM555. (Electronic circuit design added 02/05)


AN996: Designing a Digital Compass using the PIC18f2520: Microchip Application Note Published 8-Aug-05 (app note added 2/06)

Digital Compass Schematic: (circuit added 9/04)

Dinsmore 1490 Digital Compass: (electronic circuit added 4/05)

Electronic Compass Controller: Eventually we all want to know just where our robot is, so we can choose an absolute direction. Usually this type of device is quite expensive. However to our rescue comes.... (added 3/07)

Ultra Low Noise Precision High Speed Op Amps: Linear Technology LT1028(app note added 02/05)

AN728: Remote Keyless Entry and Convenience Center Reference Design with LIN Bus Interface: Microchip Application Note Published 26-Sep-02 (app note added 2/06)

Combination Lock (PIC16F84): (electronic diagram added 6/03)

Combination Lock for Car Liftgate: (circuit / schematic design added 6/06)

Electronic Combination Lock with AVR: (electronic schematic / circuit added 2/05)

Electronic Card Lock System: (electronic Circuit / Schematic added 10/04)

Digital Electronic Lock: (electronic schematic / circuit added 11/05)

Single Button Lock Provides High Security: 03/04/99 EDN-Design Ideas / (added 5/03) Figure 1 is the block diagram of an easily programmed, single-button combination lock. You operate the lock by using a series of short and long pulses from a momentary switch that masquerades as a doorbell button. The circuit uses inexpensive CMOS logic. The retriggerable timer, T1, locks out entries made after the T1 code-entry window, thereby greatly enhancing security. The circuit in Figure 2 operates as follows: The Schmitt-trigger quad NAND gate, IC1, debounces the code-entry switch and, with the aid of simple analog circuitry, produces separate outputs for activation times of less than and more than 0.3 sec. These outputs connect to the select gate, IC5. The initial entry also sets timer T1 to enable the decoded decade counter, IC3. Each entry clocks IC3.

Simple Code Lock: (electronic Circuit / Schematic added 10/04)

Failed Power Light: turns on small low voltage lighting when mains power disappears (added 7/03)

Analog Encoding: Convert switches and sensors into DMX signals. Uses are found in Haunted houses, stage plays, med events, holiday light animations, anytime you want to control DMX compatible equipment. Fog machines and strobe lights can be independly controlled be remote switches or sensors. (added 02/05)

BA1404 Stereo Encoder: BA1404 used as only stereo encoder. (circuit added 8/06)

Digital Position Encoder Does Away withADC: 05/08/97 EDN-Design Ideas / (added 6/06)

KEELOQ® Manchester Encoding Receive Routines: Microchip Application Note Published 11-May-01 (app note added 2/06)

PIC Based Packet Radio Encoder: (circuit / schematic design added 6/06)

Remote Control Encoder/Decoder with PIC16c620 and PIC12c508: (circuit / schematic design added 6/06)

Rotary Encoder Mates with Digital Potentiometer: 02/06/03 EDN Design Ideas / (added 1/05) 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....

Veronica Stereo Encoder: Uses 76KHz crystal (circuit added 8/06)


F


SB-104: Fax Solution Card: National Semiconductor - Application Note (added 2/06)


Fax saver cuts wear, tear, and power: 1/8/98 EDN-Design Ideas / (added 4/'02)-- Less than $20 to cut wear and tear on your fax machine while saving power, circuit intercepts the incoming ring signal and powers up the fax machine in time to receive the fax and then turns off the fax machine after a predetermined time and awaits the next incoming fax


2 Watt Amplifier #1: (circuit / schematic design added 6/06)

2 Watt Amplifier #2: Low distortion Amplifier using discrete components (added 6/06)

2 Watt Amplifier #3: (schematic / circuit design added 9/02)

500W, Class E 27.12 MHz Amplifier Using A Single Plastic MOSFET: Application Note Microsemi-formerly Advanced Power Technology APT9903 ( app note added 2/07)

2N2222 40 Meter CW/DSB Tranceiver: (circuit / schematic design added 6/06)

AB-45 / DVD Applications: Fairchild Application Notes / (app note added 6/06)

AB-46 / DVD Applications: Fairchild Application Notes / (app note added 6/06)

AB-47 / DVD Applications: Fairchild Application Notes / (app note added 6/06)

AB-49 / DVD Applications: Fairchild Application Notes / (app note added 6/06)

A Thermoelectric Cooler Temperature Controller for Fiber Optic Lasers: AN89 Linear Technology This application note presents circuitry for maintaining 0.01°C temperature control of fiber optic lasers over wide ambient range variations. The circuitry also features high efficiency power delivery, compact size and low noise. Detailed descriptions of circuitry and results are given with special emphasis on rmal loop optimization. An appended section covers practical considerations for rmoelectric cooler-based control loops.

DVD Applications / AB-46: Fairchild Application Notes / (app note added 6/06)

DVD Applications / AB-47: Fairchild Application Notes / (app note added 6/06)

DVD Applications / AB-49: Fairchild Application Notes / (app note added 6/06)

AN677: Designing a Base Station Coil for the HCS410: Microchip Application Note Published 7-Aug-98 (app note added 2/06)

Field Strength Meter (zen 22142): (electronic circuit added 7/03)

Field Strength Meter for the137 Khz Band: (electronic circuit added 4/05)

RF field strength meter Mk1: (schematic / circuit added e/07)

RF field strength meter: (electronic circuit added 3/07)

Fire Alarm: This circuit warns the user against fire accidents. It relies on the smoke that is produced in the event of a fire. When this smoke passes between a bulb and an LDR, the amount of light falling on the LDR decreases. This causes the resistance of LDR to increase and the voltage at the base of the transistor is pulled high due to which the supply to the COB (chip-on-board) is completed. Different COBs are available in the market to generate different sounds. The choice of the COB depends on the user. The signal generated by COB is amplified by an audio amplifier. In this circuit, the audio power amplifier is wired around IC TDA 2002. The sensitivity of the circuit depends on the distance between bulb and LDR as well as setting of preset VR1. Thus by placing the bulb and the LDR at appropriate distances, one may vary preset VR1 to get optimum sensitivity. An ON/OFF switch is suggested to turn the circuit on and off as desirable. (added 8/06)

60w Ac-DC Flyback Converter: Universal AC line input Fully assembled and tested power supply with DC containing all design documentation Features: 0-4A Iout @ 15V, 87% efficiency at high line, Short Circuit protection, Over Voltage protection (added 6/06)

Design Guidelines for RCD Snubber of Flyback / AN-4147: Fairchild Application Notes / (app note added 6/06)

Design Guidelines for Off-line Flyback Converters using FPS / AN-4137: Fairchild Application Notes / (app note added 6/06)

AN-H24: Expected Voltages and Waveforms HV9120-Controlled Flyback Converter: Supertex Semiconductors (app note added 6/06)

AN-777: LM2577 Three Output, Isolated Flyback Regulator: National Semiconductor Application Note (app note added 2/06)

AN-4137 / Design Guidelines for Off-line Flyback Converters using FPS: Fairchild Application Notes / (app note added 6/06)

Fluid Level Detector #1: (added 10/02)

Fluid Level Detector #2: (Electronic Circuit / Schematic added 10/04)

Fluid Level Control Systems Utilizing the LM1830: National Semiconductor - Application Note (added 2/06)

(AN-13) LX1686 Backlight CCFL Direct Drive Design Reference: Application Note Microsemi 1401 (added 3/07)

20ma LED Ballast: I use this circuit for general use to power white LEDs, like a headset light I use on my desk and a keyboard light for my computer. I built it into a tiny Radio Shack project box (270-288), which y no longer sell. I put heat-shrink tubing around female output connector (RS P/N 273-1743), so that contacts are not exposed, but you can still plug and unplug it. Designed by Andrew R. Morris (added 6/06)

A 3-Way Dimming Cfl Ballast: The 3 way dimming system widely adopted in US with conventional filament lamps consists of a light bulb that has a modified Edison screw type base which allows 3 connections to be made to a special lamp socket that also has 3 connections. (added 3/05)

40 Watt Fluorescent Lamp Inverter: This40W fluorescent lamp inverter allows you to run40W fluorescent tubes from any12V source capable of delivering3A. (added 4/02)

AN-378: A Novel Process for Vacuum Fluorescent (VF) Display Drivers: National Semiconductor Application Note (app note added 6/06)

AN-42001 / Low Cost Non-Dimming 220V Ballast Design: Fairchild Application Notes / (app note added 6/06)

Black Light: (circuit added 7/02)

2 Transistor FM Transmitters #2: (design added 8/03)

2 Transistor LED Flasher #1: (circuit / schematic design added 6/06)

10.7MHz FM Detector: (design added 8/03)

AN-146: FM Remote Speaker System: National Semiconductor Application Note (app note added 6/06)

AN-543 - Stereo FM Transmitter (DSP, 26,085 bytes): AN-543-StereoFMTransmitter-Analog Device Application Notes (app note added 6/06)

Crystal Controlled FM Transmitter: (circuit / schematic design added 6/06)

Add a signal strength display to an FM Receiver IC: 09/05/02 EDN Design Ideas / (Electronic Circuit added 03/06) The Philips (www.semiconductors.philips.com) TDA7000 integrates a monaural FM-radio receiver from the antenna connection to the audio output. External components include one tunable LC circuit for the local oscillator, a few capacitors, two resistors, and a potentiometer to control the variable-capacitance-diode tuning....

1W portable PLL transmitter: PLL oscillator with audio limiter. (circuit added 8/06)

2 Transistor FM Transmitters: (electronic Circuit added 03/06)

400mW VCO FM transmitter: BF199, BFR91, BFR96, varicap diode BB109. (circuit added 8/06)

Crystal Controlled FM Transmitter: (electronic Circuit added 03/06)

FM Radio Transmitter: (electronic Circuit added 03/06)

FM Transmitter (rf/2bjttx): (electronic Circuit added 03/06)

FM Transmitter with Opamp: L1 is 0.112uH (this tunes to the middle of the FM band, 98 MHz, with VC1 at its centre value of 33pF). L1 is 5 turns of 22 swg enameled copper wire close-wound on a 5mm (3/16") diameter former. Alternatively, you can have a fixed 33pF cap instead of VC1 and have L1 as an adjustable molded coil (eg UF64U from Maplin). VC1 will give you a tuning range of 85 125 MHz, and a possible choice is the Philips type polypropylene film trimmer (Maplin code WL72P). Two sets of oscillator bias resistors are given, the ones in the brackets give about 20% more RF power. Mike is our favorite Omni directional sub-mini electret (Maplin code FS43W). Ant is a (lambda / 4) whip monopole (eg 76 cms of 22 swg copper wire). Q1 is configured as a Clapp oscillator. Frequency modulation results from the audio voltage changing the transistor's base-emitter capacitance. (added 3/06)

LM110-An Improved IC Voltage Follower: National Semiconductor Application Note (app note added 2/06)

Micropower Buffered Rail-to-Rail Adjustable Volatge Source: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

Rail-to-Rail Voltage Follower/Buffer: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

High Input Impedance Source Follower: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

LB-11: The LM110: An Improved IC Voltage Follower: National Semiconductor Application Note (app note added 2/06)

Base Current Compensated High Voltage Amplifier: Unpublished 1995 The base current of a single transistor high voltage amplifier varies from unit to unit and over temperature and current. To compensate, this opamp circuit measures base current and adds an equal but opposite current to input. (added 9/04)

A New Current-Differencing Quad of Plus or Minus Input Amplifiers: National Semiconductor - Application Note (added 2/06)

AN-1110:LVDS Quad Dynamic I Cc Vs Frequency: National Semiconductor - Application Note (added 2/06)

Get More Power Out of Dual or Quad Op-Amps: National Semiconductor - Application Note (added 2/06)

LM139/LM239/LM339 a Quad of Independently Functioning Comparators: National Semiconductor - Application Note (added 2/06)

Quad MOSFET Drivers for High: Supertex Semiconductors (app note added 2/06)

Quad Output Switching Converter Provides Power for Large TFT LCD Panels: DN349 - Design Notes (Linear Technology) (added 1/06)

CLC730145, CLC730132 (Soic and Tssop) Quad High-Speed Buffer Evaluation Boards: National Semiconductor - Application Note (added 2/06)

Laser Communication System: This is a simple Laser communication system. It can transmit and receive signal from any audio device.Communication distance is few meters. All components are not critical. Transistor 2N2222 may be on the coolrib. Laser diode is from laser pointer (Electronic circuit design added 02/05)

Cold Activated Switch: The thermistor used has a resistance of 15k at 25 degrees and 45k at 0 degrees celsius. A suitable bead type thermistor is found in the Maplin catalogue. The 100k pot allows this circuit to trigger over a wide range of temperatures. A slight amount of hysteresis is provided by inclusion of the 270k resistor. This prevents relay chatter when temperature is near the switching threshold of this circuit. (added 2/06)

Frost Alarm #3: (schematic / circuit design added 9/02)

Fridge Door Alarm: (circuit added 9/04)

Laser Link Communicator: audio transmission up to few hundred meters (Circuit / schematic design added 6/06)

4 Hints for Making Better Microwave Counter Measurements: Agilent Application Note (Circuit / schematic design added 6/06)