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Electronic, PC, Microprocessor &  Mircro Controller based Kits & Projects for School &  College level students




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Power Supplies:
AC to DC Converters / Linear / Inverters

1.5V to 5V Converter - In many cases can be very handy to be able to convert 1.5V to 5V. Then you can power microcontroller or LED from a single AA or AAA battery. It is simple to do this as there are special IC�s as MAXIM MAX1674 or MAX7176. This is step-up DC-DC converter that can convert voltages from 0.7V to any in range from 2V to 5.5V. MAX1676 have already preset pins for 3.3V and 5V, that makes easer integration in 3.3 and 5V circuits. IC can dissipate up to 444mW. ….(electronic schematic)
10W HF Linear Amplifier - (circuit / schematic design)
12 Volt to 9 Volt DC Converter - Car Converter for12 Volt to 9V (Tony van Roon's electronic design)
122 Volt AC Lamp Dimmer Full Wave SCR - (circuit / schematic design)
123 VAC Lamp Dimmer (full wave SCR) - The full wave phase control circuit below was found in a RCA power circuits book from 1969. The load is placed in series with the AC line and the four diodes provide a full wave rectified voltage to the anode of a SCR. Two small....(electronic diagram)
12V DC to 220V 100W Inverter with 4047 IC & IRF540 - This is 100W inverter circuit. It uses 4047 IC and IRF540 Mosfet instead of 2N3055 transistor. Power output is 100W from 2-3A transformer. ….(electronic schematic)
12V Fluorescent Inverter - Build this 20 watt Fluoro Inverter,  it drives two 20-watt tubes or a 40-watt tube!….(electronic circuit)
12V to 110V/ 220V 500W Inverter  - Using this circuit you can convert the 12V dc in to the 220V Ac. In this circuit 4047 is use to generate the square wave of 50hz and amplify the current and then amplify the voltage by using the step transformer. How to calculate transformer rating The basic formula is P=VI and between input output of the transformer we have Power input = Power output For example if we want a 220W output at 220V then we need 1A at the output. Then at the input we must have at least 18.3V at 12V because: 12V*18.3 = 220v*1 So you have to wind the step up transformer 12v to 220v but input winding must be capable to bear 20A. ….(electronic schematic)
12V to 120V Inverter - Have you ever wanted to run a TV, stereo or other appliance while on the road or camping? Well, this inverter should solve that problem. It takes 12 VDC and steps it up to 120 VAC. The wattage depends on which transistors you use for Q1 and Q2, as well as how "big" a transformer you use for T1. The inverter can be constructed to supply anywhere from 1 to 1000 (1 KW) watts. ….(circuit design)
12V to 120VAC inverter - (Tony van Roon's schematic)
12V to 220V 100W Inverter  - This is a simple 100W inverter that can be used to achieve 110V or 220V from 12V. Circuit uses 2N3055 output transistors that are easily available. Output voltage depends on the type of transformer being used. ….(circuit design)
12W AC-DC Flyback converter - Fully assembled and tested power supply with DC containing all design documentation Features: Universal AC line input, 0-1A Iout @ 12V, 84% efficiency at high line, Short Circuit protection, Over Voltage protection
18v AC to DC Power Supply - This is a classic linear power supply which produces a regulated 18v, rated at about 1 amp. (designed by David A. Johnson)
240VAC To 5VDC Power Supply - This is simple way to power some 5v logic from a 240vac source.  If a 120vac power adapter is used, the circuit will also work for 120vac power lines. ….(designed by David A. Johnson)
3W HF QRP Linear Amplifier - (circuit / schematic design)
500mW HF Linear Amplifier - (circuit / schematic design)
500w HF Linear Amplifier - (circuit / schematic design)
500W Mos-Fet Power Inverter from 12V to 110V/220V  - This circuit will provide a very stable "Square Wave" Output Voltage. Frequency of operation is determined by a pot and is normally set to 60 Hz. Various "off the shelf" transformers can be used. Or Custom wind your own FOR BEST RESULTS. Additional MosFets can be paralleled for higher power. It is recommended to Have a "Fuse" in the Power Line and to always have a "Load connected", while power is being applied. The Fuse should be rated at 32 volts and should be aproximately 10 Amps per 100 watts of output. The Power leads must be heavy enough wire to handle this High Current Draw! ….(design)
50V 3A Stabilized Power Supply with 2N3055 - Many times we needed a stabilized, together regulated power supply and high relatively output voltage. These specifications him it cover our circuit. It 's a circuit that can give in his exit + 40V until + 60V 3A, with simultaneous stabilization. The materials that use is very simple and will not exist difficulties in the manufacture, is enough you are careful certain points. 1 ] For output voltages smaller of + 50V until + 40V, the Q1 is hot enough, so that it needs one big heatsink. ….(design)
6 to 12 Volt Converter (Aaron Cake) - This circuit can provide up to 800mA of12V power from a 6V supply. The circuit is simple, about 75% efficient and quite useful.
600 Volt Power Supply - simple 600 Volt DC power supply. Convert 230V AC to 300V and 600V DC.
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
80V Linear Regulator is Micropower - DN314  Design Notes (Linear Technology) (app note)
90W AC-DC Flyback converter - Fully assembled and tested power supply with DC containing all design documentation Features: Universal AC line input, 0-6A Iout @ 15V, 83% efficiency at high line, Short Circuit protection, Over Voltage protection
AN-1148: Linear Regulators: Theory of Operation & Compensation - National Semiconductor Application Note  (app note)
AN-262: Low-Noise Low Drop-Out Regulator for Portable Equipment - AN-262 Analog Devices Application Note  (app note)
AN-60-004  Ultra-Linear 50W Amplifiers 20-512MHz LZY-1 - Application Note MiniCircuits.com  (app note)
AN-60-005  Ultra-Linear 32W Amplifiers 500-1000MHz LZY-2 - Application Note MiniCircuits.com  (app note)
AN-60-009  High IP3, wide band, balanced linear power Amplifier HELA-10 - Application Note MiniCircuits.com  (app note)
AN-D10: Off-Line Compact Universal Linear Regulator - Supertex Semiconductors  (app note)
AN-D14: LP07 Series: Low Dropout 3.0 Volt Linear Regulator - Supertex Semiconductors  (app note)
AN-H22: Customizing the Linear Circuitry Response of HV91 - Supertex Semiconductors  (app note)
AN-H40: High Voltage Linear Regulator & Constant Current - Supertex Semiconductors  (app note)
Apex-AN35 PWM AC/DC Power Supply Design - 12/1999, AN35UREVA : 332 Kb (Apex App Note)
Automobile Interior Light Fader - This circuit is similar to the fading eyes circuit above and is used to slowly brighten and fade interior lights of older cars. The circuit is based around the LM324 low power opamp which draws around 3mA of current, so it won't bother the battery if left connected for extended periods....(circuits)
Bidirectionall power inverter - 08/02/01 EDN-Design Ideas: If you want to swap charge in either direction between unevenly loaded positive and negative battery buses, you need an inverting dc transformer. One implementation is the symmetrical flyback converter shown in Figure 1. The circuit can generate a negative output.....(design idea)
Caps Provide Voltage Boost To Series Regulator - This circuit adds some capacitors and diodes to a traditional transformer type series regulator circuit to extend the normal operating range. It can insure regulation during low line voltage conditions or it can squeeze a few more watts out of a plug-in-the-wall power adapter power supply. ….(designed by David A. Johnson)
Circuit Forms Constant Current SCR - 02/01/01 EDN-Design Ideas:.....(design idea)
Circuit offers improved active rectification - 02/06/03 EDN-Design Ideas: Rectifiers convert ac signals to dc. You can combine a diode and a load resistor to create a half-wave rectifier, provided that the amplitude of the ac source is much larger than the forward drop of the diode (typically 0.6V). Unfortunately, you can't use this method to rectify signals that are smaller than a diode drop.....(design idea)
Classic Plus & Minus DC Power Supply - This is a classic example of a regulated DC power supply that produces both a positive 15v and a negative 15v from a 20vac wall adapter. ….(designed by David A. Johnson)
CMOS hex inverter generates Low distortion sine waves - 06/09/05 EDN-Design Ideas: Audio signal source uses hex inverter and handful of passives.....(design idea)
CMOS inverters convert RF to Digital signal - 01/05/06 EDN-Design Ideas: Hex-inverter-based design suits frequencies up to180 MHz.....(design idea)
Customizing the Linear Circuitry Response of HV91 - Supertex Semiconductors  (app note)
DC to DC Converter - The circuit below is a DC to DC converter using a standard 12 VAC center tapped power transformer wired as a blocking oscillator. The circuit is not very efficient but will produce a high voltage usable for low power applications. The input battery voltage is raised by a factor of 10 across the transformer and further raised by a voltage tripler consisting of three capacitors and diodes connected to the high voltage side of the transformer.....(circuit)
EPR-32: 25 Watt Multiple Output TOP245P Supply - This design kit is an AC-DC power supply with universal input and 4 outputs. The design, rated for 20 W (25 W peak), is implemented using a TOP245P device from the TOPSwitch-GX IC family and an EEL25 core in a flyback topology.
Fast Rectifier Circumvents Input Level Effects - 12/22/94 EDN-Design Ideas: All diode-based rectifier circuits suffer from a signal-level-dependent frequency response. This response occurs because the dynamic impedance of the diodes varies as the signal level changes. The result is a slower frequency response and distorted rectified outputs at low signal levels compared with high levels. An alternative approach.....(design idea)
Full wave rectifier operates to 200 MHz - 07/20/95 EDN-Design Ideas: The circuit in Figure 1 uses current-feedback amplifiers to implement a wideband full-wave rectifier for applications such as a control/AGC system reference or as an amplitude indicator. Putting the full-wave-rectifier diodes in the feedback loop of an op amp works better than does using simple diode-based rectifiers. The op amp's loop gain.....(design idea)
High Efficiency Linear & Switching Solutions for Splitting a Digital Supply - DN172  Design Notes (Linear Technology) (app note)
High Efficiency Linear Regulators - AN32 Linear Technology Presents circuit techniques permitting high efficiency to be obtained with linear regulation. Particular attention is given to the problem of maintaining high efficiency with widely varying inputs, outputs and loading. Appendix sections review component characteristics and measurement methods.
High IP3, wide band, balanced linear power Amplifier HELA-10 - AN-60-009  Application Note MiniCircuits.com  (app note)
High Speed Rectifier uses No Diodes - 03/03/03/95 EDN-Design Ideas: Fig 1 shows a high-speed, full-wave rectifier-or absolute-value circuit-that uses a high-speed clamping amplifier, IC2. This circuit is faster and performs better than rectifiers employing diodes in their amplifiers' feedback paths. These diode-based circuits have limitations at lower signal-input levels and higher bandwidths. These limitations.....(design idea)
High Voltage Linear Regulator & Constant Current - Supertex Semiconductors  (app note)
Introduction to Schottky Rectifiers - MicroNote 401 from Microsem  (app note)
LB-8: Precision AC/DC Converters - National Semiconductor Application Note  (app note)
Linear regulator=Low cost DC/DC converter - 06/13/02 EDN-Design Ideas: The circuit in Figure 1 is a good choice if you need a power supply with high efficiency and you don't want to use expensive dc/dc-converter ICs. The heart of the circuit is IC1, the common, inexpensive LM7805 linear regulator. The external switch is a pnp transistor; the circuit can easily source more than 1A output current.....(design idea)
Linear Regulators: Theory of Operation & Compensation - National Semiconductor Application Note  (app note)
Low Power 12,000 Volt Power Supply - If you need about 12,000 volts DC for an ion generator this circuit might be the ticket. It draws power from the 120vac power line but it uses a small 6KV camera flash trigger coil. The output signal is isolated from the power line. Although the circuit can only deliver about 5uA of current it can produce dangerous shocks, so be careful. ….(designed by David A. Johnson)
Low-Noise Low Drop-Out Regulator for Portable Equipment - AN-262 Analog Devices Application Note  (app note)
LP07 Series: Low Dropout 3.0 Volt Linear Regulator - Supertex Semiconductors  (app note)
Miniature Isolated AC/DC Power Supply - This circuit uses a novel approach to produce a fully isolated and regulated 5 volts @30ma from the 120vac power line. It uses two tiny SCRs that alternately discharge two capacitors through a miniature high frequency transformer. The voltage spikes produced through the transformer are rectified, filtered and regulated. A very common 8 ohm audio impedance matching transformer can be used for the transformer. Published in EDN, Feb. 17, 1992 ….(designed by David A. Johnson)
MOSFET Switch Provides Efficient AC/DC Conversion - 02/17/00 EDN-Design Ideas:.....(design idea)
Motor Accu Lader  (Dutch language) - (circuit design)
Non-isolated Off-line AC to DC Power Supply - This compact efficient circuit can provide up to 100ma of a regulated 5 volts from an AC power source ranging from 20vac to 120vac. ….(designed by David A. Johnson)
Off-Line Compact Universal Linear Regulator - Supertex Semiconductors  (app note)
Off-Line Power Supply Does Not Require Filtering to Meet FCC Emission Requirements - DN175  Design Notes (Linear Technology) (app note)
One 9 Volt Battery gives +18 +25 +33V - This circuit is based on MAX1044 is a charge pump converter.
One Watt 2.45 GHz Linear Amplifier - (circuit / schematic design)
OpAmp Rectifier Signals Input State - 07/21/94 EDN-Design Ideas: The op-amp rectifier in Fig 1 operates from a single supply and provides a logic output and an LED that indicate the state of the input voltage. The input-state indications are handy for calibration. Because the circuit operates from a single supply, the 2.5V reference determines the level around which the circuit rectifies input waveforms.....(design idea)
Output Adjustable Flyback Converter - (electronic diagram)
Precision AC/DC Converters - National Semiconductor Application Notes,28-Jun-1996 (app note)
Precision full wave Signal rectifier needs no diodes - 09/01/05 EDN-Design Ideas: Single-supply design uses two op amps.....(design idea)
Precision Rectifier is Glitch Free to 1 MHz - 05/12/94 EDN-Design Ideas: The manufacturer’s circuit for a precision, current-mode, full-wave rectifier (Fig 1a)converts a voltage signal to a current, eliminating errors arising from voltage drops across the rectifying diodes. However, just like op-amp-based rectifiers, the circuit i.....(design idea)
Precision Rectifier Reduces Ripples - 03/03/97 EDN-Design Ideas: You can use a lowpass filter to simultaneously increase a rectifier's speed and reduce or maintain the ripple voltage. The input voltage of the precision rectifier in Figure 1a is 100 mV at a frequency of 50 Hz. The output with C1 equal to0 is a double phase-rectified voltage of R2/R1.....(design idea)
PWM AC/DC Power Supply Design Apex-AN35 - Apex App Note
Rectifier tracks positive & negative peaks - 06/08/06 EDN-Design Ideas: Versatile precision rectifier also delivers full-wave output.....(design idea)
Run Switching Type AC Power Adapters on DC - I have received a couple emails from people looking for inexpensive DC to DC converters, which can convert 40v to 60v DC into say +5 or +12v.  Such input voltages are often found in new automotive and industrial applications with a typical DC voltage of 48 volts. It turns out that many, not all, but many, standard AC line operated power adapters, which use switch mode techniques, will indeed work great when supplied with DC instead of AC. The unit below works down to about 30v DC and delivers 500ma at 5v. If you draw less current, it will operate at even lower DC input voltages.... ….(designed by David A. Johnson)
SCR Voltage Regulator - Though not as accurate as a linear or a high-frequency switching regulator, an SCR voltage regulator wastes little power and creates no RFI.  Designed by Andrew R. Morris
Silicon Controlled Rectifier Model Railroad Throttles & London Model Railroad Group SCR Throttle - The following is a schematic drawing of a Silicon Controlled Rectifier type throttle for use on larger scale model railroads. Three versions of this throttle are shown on this page. They are not sophisticated designs but work well and are tough and reliable.
Step Down Rectifier Makes a Simple DC Power Supply - 04/09/98 EDN-Design Ideas:   -- A simple and useful nonisolated rectifier features voltage step-down operation, acceptable Class A line-current harmonics, inherent short-circuit protection, and, optionally, a regulated output.....(design idea)
Supply uses AC to generate 5V Power on reset - 05/16/02 EDN-Design Ideas: The need often arises for a low-cost logic supply for powering microcontrollers and related circuitry in "white-goods" products, such as industrial controllers and sensors. These applications usually include 24 or 115V ac or higher levels of ac voltage for conversion to 3.3 or 5V dc. The simplest approach to generating low-current.....(design idea)
Thermostat for 1KW Space Heater SCR controlled - Here is a simple thermostat circuit that can be used to control a relay and supply power to a small space heater through the relay contacts. The relay contacts should be rated above the current requirements for the heater.
Transformerless Mains Power Supply - This power supply does not really excel in power efficiency, but it is the cheapest and most compact solution for a small power supply. Note that the low voltage output is directly connected to the mains; it cannot be used when the low voltage part can be touched. With the component values of the schematic, the circuit can supply12V /15mA max.
Transformerless Power Supply (Aaron Cake) - (electronic circuit)
Transformerless Power Supply (jose pino) - Simple, low cost and easy to build power supply. Ideal for applications that doesn't require too much power.
Transformerless Power Supply (Len Galasso) - This power supply uses the reactance of a non-polarized capacitor at 60hz to step-down the voltage from the normal 117VAC level to about 20 volts or so, which is rectified by the diode….(circuit design)
Transformerless Power Supply (Ron J) - This circuit will supply up to about 20ma at 12 volts. It uses capacitive reactance instead of resistance, so it doesn't generate very much heat. The circuit was disguising an optically-isolated triac.
Transient Protection of Darlington gain block Amplifiers - AN-60-034  Application Note MiniCircuits.com  (app note)
True RMS Detector - National Semiconductor Application Notes,28-Jun-1996 / (app note)
Two OpAmps Make Fast Full Wave Rectifier - 03/14/96 EDN-Design Ideas: The circuit in Figure 1 is a precision full-wave rectifier with the following characteristics: Minimal delay time between the input and output (with only one op amp in the chain); Similar delay times for positive and negative inputs; No need to match diodes or adjust resistors.  When VIN>0V, the output of op amp IC1 is negative, so ….....(design idee)
Ultra Low Drop Linear Regulator - (circuit / schematic design)
Ultra-Linear 32W Amplifiers 500-1000MHz LZY-2 - AN-60-005  Application Note MiniCircuits.com  (app note)
Ultra-Linear 50W Amplifiers 20-512MHz LZY-1 - AN-60-004  Application Note MiniCircuits.com  (app note)
Unregulated power supply - A basic full wave rectified power supply is shown below. The transformer is chosen according to the desired load. For example, if the load requires 12V at 1amp current, then a 12V, 1 amp rated transformer would do. However, when designing power supplies or most electronic circuits,....(schematic)
Uses & Advantages of MERA Dual Matched MMIC Amplifiers - Application Note MiniCircuits.com  (app note)
Using the Catalog Specifications to Determine MMIC Reliability - AN-60-030  Application Note MiniCircuits.com  (app note)
Very Low Dropout VLDO Linear Regulators Supply Low Voltage Outputs - DN292  Design Notes (Linear Technology) (app note)
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