Pulse-width modulation, is varying the duty cycle of a rectangle wave, usually with a constant frequency.
0
votes
1answer
42 views
Reducing the voltage of a PWM signal
I will be needing a 1.25V PWM input into an LED driver (AP8802) and will have to interface it with a 5v PWM output from a micro-controller (ATMEGA328). Would a simple potential divider do the job, or ...
2
votes
1answer
87 views
Designing a PWM controlled power supply for a 30W RGB LED
I am building a DMX controlled light using an Arduino, but I am not sure which power supply I should use to power the LEDs which run at 36v (10 in series, 3 rows) 30W. The main problem is whether or ...
0
votes
1answer
45 views
How to power a 150W with rechargable bateries?
I would like to build a gocart using a 150W 24V DC motor. To power it I would like to build a battery pack using 2Ah rechargeable batteries. The motor will run about 2 hours at 50% capacity (the ...
0
votes
0answers
22 views
Simulink how to convert Duty Cycle to reference voltage signals(Uref)
In Simulink I am creating a DC-DC buck converter using Average-model based VSC Universal. But one input of VSC is in Uref. For this case I need to convert Duty Cycle (D) into Uref for Input. Because ...
-2
votes
1answer
89 views
I want to create a custom LED segment display. What do I need to study? [closed]
I want to create and then order a small run of a customized mass-produced LED segment displays for an art project. They will use PWM. It is not much more complex or detailed than a 7 or 16-segment ...
0
votes
1answer
26 views
Atmega32 PWM on all four PWM pins
I am trying to control LEDs brightness using PWM on the Atmega32. I have one LED connected to each of the 4 PWM pins (OC0, OC1A, OC1B, and OC2). Using the code below, all of the LEDs are functioning ...
1
vote
1answer
46 views
Strange behavior on transformer driver
I'm trying to make a circuit to drive a transformer from a PWM signal produced by an AVR MCU. Here's the schematic:
The MCU output in fact has 2 complimentary PWMs feeding two transistor pairs. For ...
1
vote
2answers
60 views
Count PWM Pulses fed into Stepper Motor FET Driver
I am trying to (accurately) count the number of pulses fed to a stepper motor driver TI DRV8711. This driver "converts" one rising edge, depending on the settings, to a full step or microstep. The MCU ...
0
votes
0answers
44 views
4-Pin fan tach sensing gives weird results
I built a small setup to control a 4-Pin PC fan with my Arduino.
Controlling the fan speed with PWN signalling works fine.
But I can't get the tach readings right:
The sense-cable from the fan is ...
3
votes
4answers
110 views
Methods for converting PWM to +/- 10v Signal
Suppose we have a PWM signal which controls the speed of a motor and a digital pin which specifies which direction a motor is travelling in, how can we convert these signals into 1 +/- 10V signal ...
0
votes
0answers
21 views
Measuring DC-Motor stator current
I am having some doubts about my measurements, and I would like to verify them if possible.
I am using the circuit in the image, to measure the stator current of a DC-Motor, I just want to know if ...
0
votes
1answer
71 views
PWM signals averaged or not
I am using analogWrite(PWM) from Arduino UNO to control the gates of 30N06L N-channel mosfets. The values of PWM are programmed such that it controls the current through the loads for my control ...
0
votes
0answers
18 views
Controll Motor-DC using PWM in Proteus and MikroC for PIC
I am beginner (10 days) in Proteus and Mikroc, but i prefer to learn and this is the reason for my post.
I build a project using PIC16F917 and Motor-DC with L298 driver. I command motor to start ...
0
votes
1answer
44 views
0
votes
2answers
70 views
From PWM Output to Large Motor Control
This question stems from my own curiosity, so forgive any vagueness.
Imagine the following scenario:
We have a MCU which outputs a PWM signal to control a motor's speed and direction. We ultimately ...
0
votes
1answer
53 views
Can I dim my LEDs even more?
I have a PIC16F1828. I am using PWM in order to control brightness of bunch of LEDs. My goal is to dim those LEDs to the maximum point. Currently they are not dim enough.
System clock runs at ...
0
votes
1answer
47 views
LED driver circuit with both analog and pwm control
I would like to design an LED driver circuit that allows for simultaneous analog and pwm control. That is, I would like to set the the LED current using an analog signal and then be able to switch ...
0
votes
2answers
65 views
Opto-coupled PWM
Following on from this question:
I have the task of setting a voltage V_set using PWM. The challenge arises from the fact, that V_set is referenced to a different ground than the MCU.
My currently ...
0
votes
2answers
44 views
Opto-coupled PWM output
I have a circuit with two different ground levels. Using a optocoupler, I want to translate a PWM signal to the new ground level.
Does there exist a easier method than the following? (Ideally with ...
3
votes
1answer
225 views
0 to 15V PWM Signal method
I need to generate 0-15V output PWM singal ( max out put current is 4.5 mA only), using micro controller PWM feature. I observe one Design by using Two Transistor(PIC 1) ,I don't why two transistor ...
0
votes
2answers
87 views
How to drive power MOSFET by logic level signal without inverting phase?
I struggle yet another day with very simple problem (circuit).
This challenge seems to be very common, but nowhere I can find a complete solution:
I have a heavy load (12v / 1 Ohm peltier = 12A max) ...
3
votes
3answers
385 views
Power MOSFET gets hot while driving Peltier by step-down buck voltage converter
I have a TEC1-12712 Peltier element, which I am driving using Arduino microcontroller through IRFZ44N and buck step down converter (to smooth PWM).
Overall, circuit consists of:
12V, 8.5A max DC ...
1
vote
0answers
54 views
A strange problem in BLDC motor drive: PWM frequency and duty cycle go wired
I am working on a BLDC motor controller to drive a 2kW BLDC motor with six-step control. The design has two board, one MCU board and one interver board, and the picture below shows one phase drive ...
0
votes
1answer
42 views
Control USB powered light with PWM, would it work?
A few weeks ago, I asked about controlling a DC powered LED lamp using PWM here, I was told that if I can get a LED lamp that uses an external DC adapter to power up, I can use a MOSFET and control it ...
0
votes
3answers
73 views
Activating SSR for an AC motor via PWM input
I'm currently switching a single phase AC fan motor with an SSR.
Here is the following SSR:
http://www.crydom.com/en/products/catalog/s_1.pdf
I activate this relay by applying continuous analog 10V to ...
1
vote
1answer
38 views
Generating a clock from timer using PWM
I am using CC2640 from TI in one of my designs. As per the datasheet, I can output a clock of maximum 32KHz to any external circuit/IC. As per my design, I Need to provide 1MHz clock to a sensor.
...
0
votes
1answer
60 views
Motor oscillates when driven by L293D [closed]
I've got problem with steering DC motor with L293D and Arduino. I'm using DC motor from old inkjet printer and a quadrature optical encoder from the same printer to track the position. When I'm moving ...
0
votes
1answer
25 views
Light intensity control
The circuit is used to control the bank of LEDs using PWM, my problem is the value of R3 is wrong, now I used 10M ohm and it started switching on and off bt the LEDs dont shine bright which means the ...
0
votes
1answer
35 views
Low-side DC shunt motor drive
I want to drive a DC shunt motor like in the picture below. The PWM circuit with optocoupler, mosfet driver etc. is not shown. This circuit works fine on 12V DC motors. It even worked when tested on ...
3
votes
2answers
73 views
Interference from motors on PWM signal
Am building myself a robot chasis that is RC controlled. There is an RC receiver attached in solution and I have a remote RC transmitter. When the motors are not running, I get a perfectly clean ...
0
votes
1answer
51 views
soft starter code for avr
I need to control 2 DC motors (Maxon RE40) using an AVR (atmega328) through pwm.
I was wondering what is the right way to approach the situation.
Should I increment the duty-cycle at a specific time ...
0
votes
1answer
69 views
How to use an 2-axis accelerometer as a potentiometer? [closed]
I've got a couple of Memsic 2125 accelerometers around and wanted to try to use one of them to replace a pair of potentiometers in a circuit (x axis replaces pot A, y axis replaces pot B).
How would ...
2
votes
3answers
173 views
“High Voltage” Logic levels why they are rare
I'm continuing to dissect and learn from this old (1974) calculator. One thing that surprised my was that the pins of the main IC have both negative and positive voltages 0 to ±28V. Having worked ...
0
votes
2answers
47 views
Controlling brushless gimbal motor (BGM2804)
I'm using a standard board for control this type of motor (SimpleBGC), this board uses an atmeg328p e some brushless drivers. I'm writing a simple code for turn left/right with some velocity, but i'm ...
0
votes
1answer
58 views
An overall PWM system by using FPGA [closed]
I need to combine this 3 coding to form one whole PWM system by using FPGA. I tried it, there is no error, but the process is not synthesizable. Please help me.
Thank you.
This is code for ...
0
votes
0answers
17 views
How to decrease the absorption voltage in the case of an MPPT with fixed settings
I have an MPPT solar charge controller which doesn't have any option to input the custom settings. Though it works fine for new batteries but as my battery, Flooded Lead Acid 150AH, is little old and ...
0
votes
1answer
85 views
Is the PWM rail of a 4pin pwm Computer fan Positive or negative
I am wiring a 4 pin computer fan to a 12v dc power source and I am wondering the pin for the PWM is positive or negative.
-2
votes
1answer
60 views
SMPS buck convrter with PWM controller circuit
Hi there
I am designing a buck converter run on PWM circuitry for a uni project to drive a MOSFET switch and keep my output voltage constant.
The specs are:
input voltage of 20v DC +/- 4
output ...
0
votes
3answers
80 views
N-Mosfet switch circuit strange behavior laboratory power supply
I'm dealing with an N-Mosfet switch circuit to control, through PWM, the temperature of a heater resistor. The mosfet is a IRFS7430-7PPBF.
The load is driven at 12V and has a power rating of 80W.
...
1
vote
2answers
56 views
Permanent magnet DC motor earth wire
I have just inherited a piece of equipment that is powered by a 12V DC permanent magnet motor. My hope is to drive it using an Arduino PWM and a H-Bridge to manage the current requirements (7.3A ...
2
votes
2answers
37 views
Current chopping with an h-bridge and PWM
I have some stepper motors and L298N dual h-bridge drivers. I can't find exact specs for the steppers,* but similar motors from another product line have rated voltages from 2.64v to 5.8v. Since most ...
0
votes
1answer
30 views
Independently toggling two series switches to multiply two pwm signals
Preface
It is known that one can synthesize a signal into a train of boxcar pulses (pwm modulation), each with the same amplitude, if proper low pass filtration is applied to this pulse train before ...
0
votes
0answers
24 views
What's the peak voltage of the sawtooth generated by the ic SG3525 or UC3525? Does it depend on the Ct capacitor?
P.S. I need this information in order to make a closed-loop FlyBack CC-CC converter.
The Tm transfer function is related to the sawtooth peak voltage:
Thanks!
0
votes
3answers
71 views
Generating a (ideally several) PWM signal from GPIO, alternative to software-based pulse
Scenario:
I am trying to control precisely (without glitches) several servo-motors from a computer through GPIO. Final position, speed and ideally acceleration need to be controlled.
Currently I ...
-1
votes
1answer
89 views
0-5V PWM to analog 0-24VDC voltage with MOSFET
Im having trouble understanding how or if it even is possible to regulate a voltage with a MOSFET. I want to regulate an output voltage of 0-24VDC 0.5A(continuosly) with the duty cycle of a 0-5V 1kHz ...
0
votes
3answers
85 views
Directly driving 5V source MOSFET H-Bridge with 3.3V logic
I am trying to design a H-bridge circuit for my project to drive a thermoelectric cooler (TEC). Basically, I am trying to control the TEC with a voltage source driven by PWM.
Now the problem is, I ...
0
votes
2answers
61 views
Positive to negative PWM converter
I am looking for a way to convert a + 24V square wave coming from a cnc controller, to -5V. The frequency of a square wave will vary from 15kHz to 35kHz.
What methods would you suggest?
Thanks for ...
0
votes
1answer
74 views
PWM to DC converter with op amp - slowly but steadily rising output voltage
I assembled a circuit to convert a PWM signal generated by an Arduino to a DC voltage in the range 0..10 V.
I use the 10k-10u RC filter to convert the PWM signal to DC voltage in the range 0..5 V, ...
0
votes
1answer
47 views
pwm amplifier with npn bjt
I'm trying to do a pwm amplifier in order to control 3 fans with one pwm signal. Since there are three fans and according to the pwm specs allowed current per each is 5-8mA, I expect current load of ...
0
votes
1answer
42 views
Servo control with 555 timer
first of all this is for an assignment so I have certain limitations, mainly cost. The problem I'm having is I have run out of PWM inputs on my ATtiny45 but I still want to drive a servo. The two PWM ...
