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A Very Basic 12 volt Inverter - This circuit will provide a fairly stable "Square Wave" Output Voltage. Frequency of operation is Mainly determined by the 220 uF Feedback Caps. Currently about 60 Hz. Various "off the shelf" transformers can be used. __ Designed by G.L. Chemelec A worked Stepping Motor Example - Perhaps some of the most commonly available stepping motors, for the experimenter, are the head positioning motors from old diskette drives. These can be found at electronics swap meets, in computer surplus outlets, and even in trash dumpsters. In addition to a stepper, a typical full-height 5.25 inch disk drive includes a 12 volt DC motor with tachometer and motor control circuit board, two microswitches, and a matched LED-photosensor pair (schematic design 6/06) __ Designed by Douglas W. Jones
AC Motor Speed Controller - This AC motor speed controller can handle most universal type (brushed) AC motors and other loads up to about 250W. It works in much the same was a light dimmer circuit; by chopping part of the AC waveform off to effectively control voltage. Because of this functionality, the circuit will work for a wide variety of loads including incandescent light bulbs, heating elements, brushed AC motors and some transformers. __ Designed by Aaron Cake
AC Power Line Power Load Sensing Automatic Switch - WARNING: This circuit requires experience with mains wiring. Do not attempt construction unless experienced and capable. Death or serious injury may result from incorrect wiring. __ Designed by Rod Elliott ESP
AC Power Meter - If you would like to save electric energy, you first of all need to measure the AC current flowing through your appliances. AC line voltage times the measured current value gives the power. Build an AC power meter with a current transformer as shown in the schematic given above. __ Designed by MINOWA, Makoto 7N3WVM
AC Servo Motor Windmill - A windmill built around a 3 phase servo motor from an old welding robot.
Active Power Zener - Schematic only. __ Designed by Tony van Roon VA3AVR
ADC controls multiple stepper Motors - 09/14/00 EDN-Design Ideas - Typical stepper-motor control circuits use either logic gates and flip-flops or shift registers to generate the proper sequences of binary codes that produce bidirectional stepper-motor movement. A conventional stepper-motor-control circuit uses a square-wave generato Design by K Suresh, Indira Gandhi Centre for Atomic Research, Kalpakkam, India
Adjustable power supply using LM317 - voltage regulator for1.2V to35-Volt output voltages and up to1A load __ Designed by Tomi Engdahl
Adjustable Voltage Motor Controller - One of the nice things about flying electric is you can test run your motor in the house, workshop, or in the yard and the neighbors won't complain. The problem is how to control the speed of the motor. One way is to use the plane, radio, and speed control with the motor in it. That's no fun! __ Designed by One of the nice things about flying electric is you can test run your motor in the house, workshop, or in the yard and the neighbors won't complain. The problem is how to control the speed of the motor. One way is to use the plane, radio, and speed control with the motor in it. That's no fun! Mount the motor on the bench and just plug the battery into the motor. That's even worse! It's hard on the motor and gearbox.
Adjustable Voltage Regulator - Many amateurs have stopped by their local Radio Shack store and have noticed the famous LM317T adjustable voltage regulator. But, did you know that all voltage regulators are adjustable? Yes, any IC voltage regulator can be adjusted to a higher voltage than its fixed voltage by just adding a couple of resistors __ Designed by Radio Amateur Society of Norwich
Alternating CW & CCW Motor Driver - A while back a company needed a motor controller for a custom door latching system. The system used a small brush motor with a speed reduction gear to both latch and unlatch the door. When pulsed for about 250ms in the clockwise direction, the motor would unlatch the door. . . Circuit by David A. Johnson P.E.-September, 2010
Alternative Power Source for Magellan GPS Receivers - This GPS receiver is powered by 2 AA batteries. They are only strong enough for the GPS to stay on for about two hours, and this seems like quite a waste. I would like to be able to use a larger battery, and sometimes even an AC adapter. __ Designed by Ryan Janzen
Amperage Booster for 78xx's - Volt regulators such as the LM708, and LM317 series (and others) sometimes need to provide a little bit more current then they actually can handle. If that is the case, this little circuit can help out. A power transistor such as the 2N3772 or similar can be used (See the project on the 3-part variable power supply) __ Tony van Roon VA3AVR
An Intelligent 12V Fan Controller - Does your computer make more noise than it should? It's probably mostly fan noise! Slowing the fans down will reduce the noise but if you go too far, you could end up with fricassee of CPU!__ SiliconChip
An On/Off Motor Control with Brake - The circuit for the controller begins with a buffer, consisting of R1, R2, R3, and Z1A, which isolates the receiver from the rest of the circuit and makes operation of the circuit independent of the exact signal levels from the receiver. __ Designed by Stefan Vorketter
Astable Multivibrator Lights LED From a Single Cell - 08/21/08 EDN-Design Ideas - A classical multivibrator drives a step-up inductor to power an LED from a single cell Design by Luca Bruno, ITIS Hensemberger, Monza, Lissone, Italy
AT89c2051/4051 Stepper Motor Interface - M1 is a stepper taken from an old disk drive. There are five pins, i. e. , common, coil 1, 2, 3 and 4. Resistance measured between common pin and each coil is about 75 Ohms. Driving current for each coil is then needed about 60mA at +5V supply. A darlington transistor array, ULN2003 is used to increase driving capacity of the 2051 chip __ Designed by Wichit Sirichote
Audio Amp makes efficient fan controller - 11/09/00 EDN-Design Ideas - You can use discrete transistors to vary power to a fan to control its speed. However, with a simple modification, you can use an audio-amplifier IC to control a fan module (Figure 1) . The LM4872. PDF contains multiple circuits, scroll to find the one of interest Design by Wallace Ly, National Semiconductor Corp, Santa Clara, CA
Audio Signal Detecting Auto Power-On Unit - The switch detector unit is shown in Figure 1, and uses an LM358 dual opamp, and a handful of other parts. The relay switching device is a MOSFET, selected because of the almost infinite input resistance. The 2N7000 shown is recommended because it has a threshold voltage of less than 3V and is fairly cheap, but virtually any MOSFET will work just as well, even if the gate threshold is a little higher. An MTP3055 can also be used, as shown originally in this circuit. __ Designed by Rod Elliott ESP
Auto Heat Limiter for Soldering Iron - Usually a soldering iron takes a couple of minutes to get adequately heated up to melt the solder, after which the heat generated is much above the requirement and is wasted. Moreover, excessive heat decreases the life of the bit and the element, causing serious damage to the components. __ Contact: IQ Technologies
Automatic 12V Lead Acid Battery Charger - This charger will charge any 12V lead acid battery including flooded, gel and AGM. It is fully automatic and will charge at a rate up to about 4A until the battery voltage reaches a preset point at which it will switch to a very low current float charge. If the battery voltage drops again the charger will begin charging until the voltage once again reaches the cut off point. In this way it can be left connected to a battery indefinitely to maintain full charge without causing damage. An LED indicates when the battery is fully charged. __ Designed by Aaron Cake
Automatic DC Motor Brake - In many DC motor powered systems you would like the motor to quickly come to a full stop. This circuit provides an automatic electronic braking action to any DC motor ranging from 6v to 24v up to 1 amp of current. Some of the component values could be changed . . . Hobby Circuit designed by David Johnson P.E.-September, 2004
Automatic fan controller - This circuit use LM311, 2N3904 and some components
Automatic Fan Controller - Th1, the 50K thermistor, is a standard type. Mine was a bar or rectangular looking thingy. Available from Tandy/Radio-Shack. Almost any type will do. I experimented with different models from 22K to 100K and all worked fine after replacing the trimmer pot. The one used in the above circuit diagram was a 50K model. This 50K was measured at exactly 25 °C and with 10% tolerance. The resistance increases as the surrounding temperature decreases. Tolerance for my application (cooling a large powersupply coolrib) is 10%. __ Designed by Izhar Fareed
Automatic Fan Controller for AIR-Conditioners - Many central air-conditioning systems (ACs) have the option for cooling and heating both. These have a fan for blowing hot or cold air drawn from a central unit, often with no...__ Electronics Projects for You
Automatic Speed-Controller for Fans & Coolers - During summer nights, the temperature is initially quite high. As time passes, the temperature starts dropping. Also, after a person falls asleep, the metabolic rate of one’s body decreases. Thus, initially...__ Electronics Projects for You
Automatic Temperature Controlled Fan - Here is a circuit through which the speed of a fan can be linearly controlled automatically, depending on the room temperature. The circuit is highly efficient as it uses thyristors for...__ Electronics Projects for You
Automatic Wash Basin Mirror Lamp Controller - In restaurants, auditoria and even homes, many a times we forget to switch off the wash basin mirror lamp after use. The circuit given here automatically switches on the wash basin...__ Electronics Projects for You
Automatic Washbasin Tap Controller - Make your washbasin tap work automatically when you put your hands just below the water tap outlet. This infrared-based system detects any interruption of the IR rays by your hands or...__ Electronics Projects for You
Automatic Water Pump Controller - Here’s a circuit that automatically controls the water pump motor. The motor gets automatically switched on when water in the overhead tank (OHT) falls below the lower limit. Similarly, it gets...__ Electronics Projects for You
Automatic Water Tank Filler - Municipal corporations in many cities supply water during early morning hours. So, you have to wake up early, just to switch on your motor pump and wait till your water tank is filled up. Further, there is no control for overflow of the tank. Many times you come to know of your overflowing tank only when your neighbour informs you. __ Designed by © EFY Enterprises Pvt. Ltd.
Automatic Bilge Pump Sensor - This simple circuit will keep your engine bay under control and draws no current while in standby __ Contact: P. Townshend - EduTek Ltd
AVR microcontroller makes improved Motor controller - 10/17/02 EDN-Design Ideas - The circuit in Figure 1 provIdeas a novel method of reading the pulse train using an Atmel (www.atmel.com] AVR processor, from a typical radio-controlled receiver, and to determine the velocity of a motor. To capture the pulse train from a typical receiver, you need an external interrupt that triggers based on a rising and a falling edge Design by Anthony Di Tommaso, Cranberry Township, PA, and George Simonoff, Petersburg, OH |
