Battery Voltage Monitor - R1 controls the trip-point of the circuit. adjust it accordingly. to reverse the logic (have the led light up when the battery has at least X amount of power,) connect the led to ground through R4. __ Designed by Andy Wilson BEAM Stepper - 74AC240-based circuit to drive small bipolar stepper motors (e. g. , ones in floppy drives) __ Designed by Wilf Rigter
BEAM Stepper drive - The 74AC240 stepper driver works by alternately enabling each half of the buffer. Only one half can be enabled at a time. Let's assume that the top half of the driver is enabled. U1A & U1B along with R8, C1, and the input protection resistor R7 form a square wave oscillator. The outputs of U1A & U1B directly drive one coil of a bipolar stepper motor. __ Designed by Duane Johnson and Wilf Rigter
Bidirectional Motor Speed Controller - Easy-to-build project can control the speed of 12-24 V DC motors in both forward and reverse directions.__ SiliconChip
Bi-Directional Motor Speed Regulator - This circuit shows the concept I used in the drill motor control that I submitted earlier. I cam up with it in 1994 when I built the device. My algebra and my patience are a bit too rusty at my age now to write an equation that describes the relationship between the BEMF of the motor and Vin. __ Designed by Andrew R. Morris
Bipolar Stepper Motor Control - First, we want to explain how such a controller works and what’s involved. A bipolar motor has two windings, and thus four leads. Each winding can carry a positive current, a negative current or no current. This is indicated in Table 1 by a ‘+’, a ‘–‘ or a blank. A binary counter (IC1) receives
Bipolar Stepper Motor Control - In this circuit, a potentiometer controls both the speed and direction of a small bipolar stepping motor like those found in many 5 1/4" floppy disk drives. Note that the bipolar motors are distinguished from "unipolar" types, in that bipolar units have two coils instead of four, and four wires instead of five. With the potentiometer at the extreme counterclockwise position, the motor runs counterclockwise at the maximum speed. Rotating the potentiometer toward the center slows the motor, until it stops. Continuing potentiometer rotation clockwise, the motor starts to run clockwise, increasing in speed to the maximum clockwise position __ Designed by Arthur Harrison
Boost converter controls 12V fan from 5V supply - 12/12/97 EDN-Design Ideas - Temperature-controlled PWM boost converter allows operation of a12V brushless dc fan from a5V supply. Design by John McNeill, Worcester Polytechnic Institute, Worcester, MA
Breadboard supply-very Low dropout adjustable power supply - This project details the design of a very low dropout adjustable power supply. A good power supply is essential to electronic projects. While there are many existing designs for adjustable power supplies, this one makes improvements that make it more useful for hobby designs. __ Designed by © Lucky Larry
Bridge heA - D - The LDR's were hand-picked. Got two packages of them from Radio Shack, looking for at least two pairs of similar parts. Then added wire-wrap pin sockets, to the circuit, so that the LDR's could be plugged in. Currently, the 0.33UF cap is not being used on my B-Head's. I made a long J-hook from "Jumbo Paper Clips", attached it to the motor shaft, and then hung it from my rear-view mirror so it can "see the lights" __ Designed by Paul T. Barton
Brush DC Motor Drive - The LS7260 series of Brushless DC Motor Commutator ICs can easily be used to drive Brush DC motors. All the features for driving Brushless DC motors still apply, including Enable, Speed Control, Overcurrent Protection and Braking. Figure 1 illustrates a Brush DC motor driven by a Power FET H-Bridge__ LSI Computer Systems
Brush Motor Speed 12V Controller - In many applications, you would like to hold the speed of a motor constant, even as variations in the power supply voltage or mechanical load try to change its speed. In other applications, the average current to the motor needs to be limited, so the. . . Circuit by Dave Johnson P.E.-May, 2007
Brushless DC electric Motor control by CPLD - The main area for application of brushless direct current motors (BLDC) is positioning. In this article I am going to describe a simple solution to operation with two phase sine/cosine BLDC.
The main idea is to generate sine and cosine by Pulse Weight Modulation (PWM) using configurable logic for example field programmable array (FPGA) or complex programmable logic device (CPLD) .
Brushless DC Motor Driver - Use of brushless DC motors (BLDCs) is on the rise. But their control usually requires rotor-position information for selecting the appropriate commutation angle. Normally, a Hall Effect sensor is used to...__ Electronics Projects for You
Brushless PM Motor Drive - Monolithic full-bridge and half-bridge gate drivers are available and include protection, dead time and supply circuits. Bi-directional brush DC motor drive __ Designed by STMicroelectronics
Build a 10 Amp 13.8 Volt Power Supply - Sometimes amateurs like to home-brew their power supplies instead of purchasing one off the shelf at any of the major ham radio retail dealers. The advantage to rolling your own power supply is that it teaches us how they work and makes it easier to troubleshoot and repair other power supply units in the shack. It should be noted that there is no real cost advantage to building your own power supply unless you can get a large power transformer and heat sink for a super low price. Of course rolling our own gives us the ability to customize the circuit and make it even more reliable than commercial units. __ Designed by N1HFX
Build a breadboard power Module for integrateds - When I began building effects, I built directly on perfboard and sometimes, I had never before heard the circuit. This led to, on a few occasions, being disappointed with the sound and later de-soldering the valuable parts and throwing away the rest. Other times, I would want to modify various components and would need the soldering iron for that as well. __ Contact: holler @ runoffgroove.Com
Build a High Performance Voltage Regulator from Discrete Components - While integrated circuits have become a staple of all modern circuit designs, it is still possible to build circuits without IC’s and still achieve a high level of performance. The circuit in Figure 1 is a high performance 5 volt voltage regulator built using discrete components that are readily available. I have used no IC’s and I have even substituted a 1N4001 in lieu of a zener diode. The regulator output voltage varies by a mere .4% and has current limiting at 1.5 amps along with short circuit protection. With the exception of thermal shutdown, this circuit closely matches the performance of the 7805 5 volt regulator IC. __ Designed by N1HFX
Build a Simple Circuit Rechargeable CMOS
Battery - Occasionally we come across a computer motherboard that seems to eat those CR2032 batteries every 4 to 5 months. This is particularly frustrating because the computer works perfectly once booted but all the important BIOS settings are lost when the CR2032 battery fails. This is very irritating if the affected computer will not boot up with the default BIOS settings. I recently had a computer motherboard with this same irritating phenomenon. A test revealed that the current drain __ Designed by Radio Amateur Society of Norwich N1HFX
Build an On/Off Motor Controller 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 |