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Encoder & PC make complete Motor-control systE - M - 12-Dec-02 EDN-Design Ideas - This design idea combines a simple ISA-bus-resident interface circuit; a garden-variety PC; a high-resolution optical shaft encoder; and a PWM-controlled, 0.05-hp, brushed, permanent-magnet dc motor to make a high-precision and high-power motion-control system. The system sequences the precise rotation of an evacuated steel bell jar several feet in diameter, such as those used in molecular-beam Design by Steve Woodward, University of North Carolina, Chapel Hill, NC Engine Control Unit Schematics - The original plans for the ECU called for a very simple unit designed to keep the engine within parameters. I was going to use a Basic Stamp 2, a pressure transducer, and a thermocouple. As work progressed, I realized that greater functionality could be obtained with a proper tachometer, and the use of a faster, more capable, compiled Microchip controller. I will leave these circuits posted, but the final ECU will make much greater use of the inherent capabilities of the PIC16F876, 28-pin microcontroller, especially for tasks like driving the pump and the glow plug.
Expanded Scale Battery Volt Meter - This circuit is used to measure the voltage on a 12V (nominal) lead acid rechargeable battery system. It was specifically designed for use in solar powered systems, but is general enough that it can be used for automotive or other 12V systems. Lead acid batteries normally spend their working lifetime in the voltage range of 11-15 Volts. This meter circuit __ Designed by G. Forrest Cook
Fan control - As we begin to enjoy those lazy hazy days of summer, the most important thing on most of our minds is how to keep cool during those hot days. For some of us that means turning up the old air conditioner and sipping on a nice cold glass of our favorite soft drink. However, we often forget about an equally important __ Designed by Radio Amateur Society of Norwich
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
Fan controller adapts to system temperature - 09/25/97 EDN-Design Ideas - Any piece of electronic equipment--whether it be a lab instrument, an audio amplifier, or a PC--that relies on a cooling fan to control internal temperature is a potential source of noise pollution or even hearing damage. Most of the time, the fan's noise level is probably much higher than necessary, because it has enough capacity to move Design by Kerry Lacanette, National Semiconductor, Tucson, AZ
Fan controller made efficient with an Audio Amp - 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
Fan Dual-Controller - Each fan turns off when the temperature drops 5 degrees below its turn-on temperature. For example, if the dial is set to 80 degrees, the fan turns on at 80 degrees and turns off at 75 degrees. This prevents the fan from cycling on and off rapidly, which would occur if the fan turned on at 80, started to cool the cabinet, and then immediately turned off at 79.
Fan On/Off Control By Light - This circuit lets you turn on/off a fan by just directing torchlight or other light toward its light-dependent resistor (LDR) . The circuit is powered from a 5V power supply. Preset VR1 and...__ Electronics Projects for You
Fan Remote Control - November 09, 2011 - Design News: The gadget comes with off/on, three fan speeds, and multicolored LEDs to indicate the fan’s speed. As a bonus, it beeps to indicate that the fan got your message. __ Designed by Andrew R. Morris, Gadget Freak-Case #198, Design News
Fan Speed Controller - Simple circuit for fan speed control based on thermal feedback. To reduce product noise. Design Idea was rejected! Years later companies are making millions from such circuits. __ Designed by Jim Haggerman, Hagerman Technology LLC
FAN Thermostat Controlled By IR Remote Controller - This circuit measures temperature in Celsius and displays it on an alphanumeric LCD. When temperature rise to 40C an alarm is activated and the electromechanical relay is also activated which drives a fan to keep the temperature at a level. Another feature of this circuit is that you can use the keys "1, 2, 3, 4" of a Philips TV IR remote to turn on or off three relays. Key '4' is used to turn on or off the buzzer alarm. __ Designed by Zeeshan Raja, Peshawar Pakistan, Cecos University Of Engineering and IT
Fan Timer Based On Motorola 68HC908QT2 - My son got his fan in the bedroom. The fan has mechanical timer for 0-180mins. One day it broken. So I got the idea to use Nitron chip to replace the mechanical timer. Someone may ask me why so complicated timer made by microcontroller chip? Actually we can build a timer with 555 and a 14-stage CMOS
counter! The 555 runs astable with time constant controlled by RC and for long period timing we can divide the output frequency of 555 by a CMOS
counter. __ Designed by Wichit Sirichote
Fast Charger for Better Lead-Acid Battery Life - This peak limiter is simple and very effective. Uses discrete FET gain control
Fixed Voltage Power Supply - The fixed voltage power supply is useful in applications where an adjustable output is not required. This supply is simple, but very flexable as the voltage it outputs is dependant only on the regulator and transformer you choose. The maximum output current is 1.5A __ Designed by Aaron Cake
Flashing LED-Based Solar Engine - Voltage-Controlled Solar Engine:This design uses a flashing LED to determine the solar engine's voltage trip level. __ Designed by Wilf Rigter
Four-transistor H-bridge - an interesting 4-transistor H-bridge variant; this is cheap and easy to build, and best of all is "smokeless" (i. e. , no combination of inputs can cause the bridge to self-destruct) . __ Designed by Wilf Rigter
Frequency switch This circuit is the circuit which makes the output the high level condition when the signal of the specific frequency which is is inputted. I made this circuit in the purpose to reset the clock (adjust the minute correctly) , detecting the time signal of the radio. I think that it is possible to apply with the variety as well as it, too. __ Designed by Seiichi Inoue
Fridge Saver - This circuit waits 5 minutes before re-applying the power to a refrigerator to prevent it from having to start up under pressure after a brief power outage. This is highly stressful for the compressor and the thermal cut-out switch built into the compress __ Designed by Andrew R. Morris
Fridge Saver - This circuit waits 5 minutes before re-applying the power to a refrigerator to prevent it from having to start up under pressure after a brief power outage. This is highly stressful for the compressor and the thermal cut-out switch built into the compressor. This device prevents frequent brief power interruptions __ Designed by Andrew R. Morris
Fridge Saver Beats the Heat - 15-Sep-10 -Design News: Do your kids, spouse, or friends take too much time scanning the contents of your refrigerator? Have your pets figured out how to open the door and keep it open for minutes at a time? You might need the Fridge Saver, a project created by Chris Popp to show how you can monitor a refrigerator--or __ Gadget Freak-Case #171
Frost Alarm - 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 __ Designed by Andy Collison
Full bridge for motor control - Before trying to understand a full bridge circuit, you may care to read up on PWM controllers, which page also describes how a half-bridge circuit works. Most full bridge motor controllers also use pwm! Designing a full-bridge PWM circuit that is reliable and 'user-proof' is actually quite difficult! 4QD released our first such controller in 1992: it was probably not the first but was certainly early in the race. __ Designed by Richard Torrens
Full-featured Dual Hbridge - Dueal non-shortin H-bridge with brake
Full-featured Dual H-bridge - I had always assumed that dynamic braking would be most effective at higher speeds. However, actual tests using a Faulhaber (micro mo) gearmotor showed that the brake would hold a motor almost stationary. These gearmotors are so well made that I can turn the 4 mm diameter shaft with light finger pressure. For the tests I had mounted a 90 mm diameter wheel, which gave me tremendous mechanical advantage. I found with the wheel mounted that I could barely turn the motor against the brake. __ Designed by Bruce Robinson |
