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Pulse Width Modulators (PWM)
PWM Circuits:  # - G     H - O     P - S     T - Z


Last Updated: November 22, 2021 03:00 PM

Circuits Designed by Dave Johnson, P.E. :

PWM Circuit for Motor Speed Control - Sometimes you want to slow down a brush type DC motor.  The most efficient way to do this is with a pulse width modulation (PWM) technique.  The hobby circuit below can operate from about 3 volts to 15 volts.  The frequency is fixed at about 2KHz but the pulse . . . Hobby Circuit designed by David Johnson P.E.-December, 2007

PWM Motor Controller uses a 555 Timer - Using a CMOS version of the 555 timer, this circuit can be used to control the speed of a motor by adjusting the duty cycle of the pulses sent to the motor . . . Hobby Circuit designed by David Johnson P.E.-February, 2007

 

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PLD code reveals PC-Board revisions-  10/17/02 EDN Design Ideas:  The PLD (programmable-logic-device] code in Listing 1 implements a pc-board-level revision-detection system that detects whether PLD pins are shorted together on a pc board.  It is often advantageous to field a single PLD programming file that works for several generations of physical hardware.  The PLD needs to understand what the board revision is, so that it can enable or disable functions, pi Design by Clive Bolton, Bolton Engineering Inc, Melrose, MA

Power MOSFET PWM motor driver-  Scroll down: 
This power MOSFET motor driver is better than the PROFET driver because it is working at a higher switch frequency of 20 kHz. This circuit also avoids the voltage drop and power loss over the power diodes present in the PROFET driver. The MOSFET transistor in this motor driver requires a special driver circuit between the PWM circuit and the MOSFET itself. The reason for this is that switching the gate voltage of the MOSFET transistor requires high transient current ( 2 A) due to relatively high capacitive load. The MOSFET transistor requires a relatively large heatsink for high current motors. __ Contact Pico Technology

Processor's PWM output controls LCD/LED driver-  27-May-04 EDN Design Ideas:  The PWM (pulse-width-modulation] output available from many microprocessors is based on an internal 8- or 16-bit counter and features a programmable duty cycle.  It is suitable for adjusting the output of an LCD driver (Figure 1) , a negative-voltage LCD driver (Figure 2], or a current-controlled LED driver (Figure 3] Design by Joe Neubauer, Maxim Integrated Products, Sunnyvale, CA

Provide 4- to 20-mA PWM control-  09/01/98 EDN Design Ideas:  The circuits in Figure 1  and Figure 3 are useful when you use 4- to 20-mA current-loop signals to control a PWM signal.  In both circuits, the minimum pulse width (corresponding to a 4-mA loop current) and the maximum pulse width (corresponding to a 20-mA loop current) are independently   FILE has many circuits, scroll down Design by Tom Gay, Darmstadt, Germany

Provides Efficient PWM-  02/18/99 EDN Design Ideas:    NOTE:     FILE has several circuits, scroll to find this one You often need to control the duty cycle of a square wave.  The circuit in Figure 1 works from a single 5V supply at a frequency of 100 kHz.  With minor component changes, you can configure it for a range of frequencies.  The circuit consists of a ramp   NOTE:  sawtooth.  oscillator and a comparator.  The circuit compares the ramp to an externally applied voltage, VCNTRL.  When VCNTRL is greater than the ramp voltage, the PWM output is 5V.  The sawtooth oscillator consists of a current source   NOTE:  R1, R2, R3, and Q1.  , a timing capacitor   NOTE:  C1.  , and the oscillator-control circuitry   NOTE:  R4, R5, R6, and IC1A The oscillator-control circuitry sets the upper and lower voltages of the timing capacitor at 3 and 1V. Design by Kenneth Levine, Eldec, Lynwood, WA

Pulse width Modudulator using 555 timer IC-  This circuit is capable of regulating 12V motors and DC light bulbs.  No coolrib required for Q1 or D3 if the current does not exceed 2A.  If it does, a sufficient coolrib for both the Schottky Diode ( D3) and MOSFET Q1 is required __ Designed by Tony van Roon  VA3AVR

Pulse Width Modulation-  (spice design) __ Designed by Rick 

Pulse Width Modulation DC Motor Control-  Often, people attempt to control DC motors with a variable resistor or variable resistor connected to a transistor.  While the latter approach works well, it generates heat and hence wastes power.  This simple pulse width modulation DC motor control eliminates these problems.  It controls the motor speed by driving the motor with short pulses.  These pulses vary in duration to change the speed of the motor.  The longer the pulses, the faster the motor turns, and vice versa. __ Designed by Aaron Cake

Pulse Width Modulator-  The IC used is a CMOS type MC14093, a quad 2-input NAND Schmitt trigger.  If you wish, it can be directly interchanged with the CMOS MC14011 but this type is noisy.  The speed is adjustable from 0-max.  Max rpm is 2/3 the supply voltage __ Designed by Tony van Roon  VA3AVR

Pulse Width Modulator, LM324-  Schematic only, no circuits description. __ Designed by Tony van Roon  VA3AVR

Pulse Width Modulators-  generating PWM waveform is extremely simple with the circuits shown in this page __ Designed by Richard Torrens

Pulse Width Position Servo control-  I have described elsewhere in these pages how normal PWM works in controlling the speed of a motor.  PWPS is an entirely different system and two should not be confused: the similarity of names is unfortunate and I suggest you forget everything you know about ordinary PWM motor speed control so you can follow this explanation. __ Designed by Richard Torrens

Pulse Width-to-Voltage Converter-  This is the circuitry that we evolved ( and discarded!) for the interface.  It is in two parts because of the mechanical design of the caddy.  The first half is a speed interface which simply translates the standard radio control pulse width to an analogue voltage which is fed to one of 4QDs motor speed controllers.  I know - the circuit looks too complicated for such a simple task, but it is in fact doing a few other tasks that the customer required. __ Designed by Richard Torrens

Pulse-Width Modulator Has Digital Control-  12-Jun-08 EDN Design Ideas:  Operating at 1 Hz, this pulse-width modulator has digital control Design by Vinay Kumar, Mysore, India

PUT pair-  2 Tr equivalent to SCRs, SCSs and other 4 layer devices __ Designed by Richard Torrens

PWM a High Current Pulse Width Control-  Newly Revise Design NOW for Either N or P Channel Mos-Fet's __ Designed by G.L. Chemelec

PWM ADC is Surprisingly Accurate-  06/09/94 EDN Design Ideas:  The reference voltage in Fig 1a's simple rail-to-rail PWM ADC is the only critical component.  The input-voltage range extends from ground to the power rail which also acts as the reference.  The circuit is essentially a variation Design by Mike Walne, Farnell Instruments, Wetherby, West Yorkshire, UK

PWM CD4094-  The IC used is a CMOS type MC14093, a quad 2-input NAND Schmitt trigger.  If you wish, it can be directly interchanged with the CMOS MC14011 but this type is noisy.  The speed is adjustable from 0-max.  Max rpm is 2/3 the supply voltage __ Designed by Tony van Roon  VA3AVR

PWM Circuit for Motor Speed Control-  Sometimes you want to slow down a brush type DC motor.  The most efficient way to do this is with a pulse width modulation ( PWM) technique.  The hobby circuit below can operate from about 3 volts to 15 volts.  The frequency is fixed at about 2KHz but the pulse . . . Hobby Circuit designed by David Johnson P.E.-December, 2007

PWM Control forHydrogen Generators-  Unlike conventional PWM Circuits, This circuit also has a special "Current Limit Control".  "If your H-Cell gets hotter and tries to draw more current, This circuit won't let it". __ Designed by G.L. Chemelec

PWM Controller-  This controller will deliver up to 30 amps and control the motor from 5% to 95%. __ 555-Timer

PWM Controller-  This PWM controller is cheap and easy to build, but has no temperature control and with components shown runs at relatively low frequency. __ Designed by © Madis Kaal

PWM controller drives LEDs from high-voltage lines-  4-Mar-04 EDN Design Ideas:  Powering LEDs from a wide dc range—say, 30 to 380V—without wasting a lot of power in the regulating block, is a difficult task when the LED current needs to be constant.  Dedicated LED drivers are available, but they usually implement boost structures and are thus inadequate for high-voltage inputs Design by Christophe Basso, On Semiconductor, Toulouse, France

PWM controls sensor's AGC-  03/29/01 EDN Design Ideas:  All electronic sensors have their limits on working distances and environmental tolerances.  Dynamic range defines a sensor's maximum allowable variations in the signal amplitude.  ACG (automatic gain control) finds wIdeaspread use in systems to extend the dynamic range.  Applications using photoelectric or ultrasonic techniques involve both emission and detection energy.  In many cases, the emission first establishes a background receiver signal as a reference, and the receiver monitors the signal and detects any changes against this reference Design by Dongjie Cheng, Allegro Microsystems, Willow Grove, PA/

PWM DC Motor control with SG3525-  This PWM DC Motor driver circuit is ideal for the accurate control of DC motors as well as other applications like lighting levels and small heaters etc.  The circuit converts a DC voltage into series of pulses, such that the pulse duration is directly proportion to the value of the DC voltage.  The great advantage of such a circuit is that almost no power is lost in the control circuit __ Contact info @ wzmicro.com

PWM DC Motor Speed Control-  This is a circuit for controlling the speed of small DC motors, it works nicely as a speed controller for an HO or N gauge model railroad __ Designed by G. Forrest Cook

PWM DC Power Controller-  This DC power supply controller is controlled by pulse width modulation PWM, generated by the circuit around timer IC2 7555 according to the formula: Duty cycle = ( ( R1 + ( VR1/2) / ( R1+R2+VR1)) x 100% Diode D1 is used to bypass resistor R2 and half the effective resistance of the “lower” section of VR1, allowing the __ Designed by Popescu Marian

PWM fan Controller-  I noticed allot of people like to use the 7V fan mod, this is fine I suppose but it is very inefficient, and it doesn't allow for RPM monitoring.  I have Built a fan controller out of fairly cheap and readily available parts that is extremely efficient, reliable and doesn't endanger your computers PSU__

PWM fan controller in an EMI-susceptible-  02/16/06  EDN Design Ideas:  Control it with either an external negative-temperature-coefficient thermistor or a PIC microcontroller and its SMBus serial-data bus Design by Dimitri Danyuk, Niles Audio Corp

PWM has digital control-  12-Jun-08 EDN Design Ideas:  Operating at 1 Hz, this pulse-width modulator has digital control Design by Vinay Kumar, Mysore, India

PWM IC makes synchronous gate driver-  02/02/99 EDN-Design Ideas (contains several designs, scroll to find this one) A system with a µP, memory, and peripherals usually requires several power-supply voltages.  Designers typically use local switching regulators to produce the desired voltage rails.  One of the most common topologies, the synchronous buck regulator, converts a 5 or 12V bus to some other, lower voltage. Design by Dimitry Goder, Switch Power Inc, Campbell, CA

PWM Logic Based Low Power MW AM Transmitter-  You can use this for safely linking your iPod to that super-retro AM valve radio that you just bought. __ Designed by Henry 

Pwm Modulator-  If you ever thought of experimenting with pulse-width modulation, this circuit should get you started nicely.  We’ve kept simplicity in mind and used a dual 555 timer, making the circuit a piece of cake.  We have even designed a small PCB for this, so building it shouldn’t be a problem at all.  This certainly isn’t__

PWM Motor Control-  PIC Project  This device acts as a variable speed control for the heater blower in a car.  It takes its power directly from the existing wiring and connects with just 2 wires.  It will also work for any 12 volt device up to 10 amps. __ Designed by Luhan Monat - Mesa Arizona

PWM Motor Controller-  Schematic only, no circuit description__ drawn Rich Rudman

PWM Motor Controller uses a 555 Timer-  Using a CMOS version of the 555 timer, this circuit can be used to control the speed of a motor by adjusting the duty cycle of the pulses sent to the motor . . . Hobby Circuit designed by David Johnson P.E.-February, 2007

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PWM Circuits:  # - G     H - O     P - S     T - Z


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