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269 Threads found on edaboard.com: Pwm Supply
hi every one, I'm using a circuit which has 2 7segment but I use 7 LEDs instead of each 7segment. this 7segments shows numbers from 10 to 35 and because of supply current limitation Just 2 LEDs can be on each time so I have to use pwm signal to turning on them. Consider I want to show 28 so 12 LEDs should be on and as I mentioned just 2 leds can b
Consider "noise" a vague term. You should better analyze interference level versus frequency and specify your clean power supply requirements. Different LDO have different degree of ripple rejection. Ripple rejection at the typical SMPS pwm frequencies is not generally good and mainly achieved by output capacitors. Respectively a good LC filter
You'll first check for pwm pulses of suitable frequency and pulse width at processor output. I see a number of circuit faults: - using high side instead of low side driver channel without a reason - resistor values R1, R5, R6 inappropriate - D4 reversed Without annotation of all supply voltages, e.g. Va, the circuit isn't readable.
I suggest you record and FFT your power supply noise, then replace mic with a resistor then use a sine signal from a sig generator and compare results. 8 bit pwm will be quite poor for sound quality. It should be a sigma delta type.
Hi, it seems if you just make a simple example, you find out what happens.... (This should be your part... at least to give some data or other informations... now we just can assume what you want to do..) Imagine you want to charge a Pb battery. When the battery is empty you will see maybe 10.5V When it is slowly full charged you will see
I don't understand your breaking action. I would expect recuperation into the battery, in this case the phase current can be a least estimated from the DC+ current measurement. Another point is that the IR2110 bootstrap supply can't be maintained without continuous low side pwm.
These SSRs don't need series resistors, the inputs can be simply parallel connected. They are full wave switching triac/thyristor switches. A low frequent "pwm" signal, e.g. can be used to vary the output power, the control method is usually named packet switching rather than pwm. It's not clear why you have problems to enable both SSR, the r
If you are bumping up against a minimum pulse limit (like, the comparator's ability to reswitch in short time) you can fall into a pulse skipping kind of behavior. Current mode pwm right about 50% can have trouble with the opposite sync or output edge "kicking" the current compare forward or back, via the supply network.
Yes, question is a bit unclear. The ?A specification is about circuit quiescent current. Unclear is a least how the "pwm" dimming shall be configured. The usual solution is to use transistor switches (BJT or MOSFET) and current limiting resistors and generate the pwm inside the processor (least part count). If you rely on constant current yo
Hello guys, I have some equipment which needs a control voltage to select the speed. At this time I use an Arduino in combination with a pwm to 0-10V converter as seen below. It works pefect, except I can't reach full speed because the device expects a control voltage from around 2-12V. 127715 Does anyone know a
Hi, what controller are you referring to? What does the datasheet say? *** Burst mode with pwm controllers usually means that the control loop at light loads is ON for one ore more cycles, then OFF for some time. This saves power, but increases ripple voltage and decreases ripple frequency. With pwm controllers you may choose if you want burst
Hi! I have a fairly simple motor controller controlling a DC motor. It's just a MCU feeding a pwm signal through a transistor, much like this one: However, I need the motor to keep running when the pwm signal is zeroed. What I have now is roughly 0-5v amplified to 0-Nv, but what I nee
hello All, i have to control Analog output using PIC32 Device pwm. i have to control Laser Driver which has a control of 0 to 5 voltage to 0 to 30 Ampere. So MY device has a PIC32MX795F516L and clocked with 80Mhz. and using OC5 to genrate pwm signal . below is the circuit of pwm input to control output signal of micro controller 0 (...)
Here are a few ways a 555 can make pwm:
we have followed the standard design of UC3845 to make 15V x 3 Amps Power supply. we have decided to use 120KHz . But we are unable achieve the same frequency of 120KHz. the frequency of the UC3845B is varying from 100KHz to 250KHz while seeing through Digital storage oscilloscope with or without Load condition.But we are able to load up to 2.5 Amp
Actually 30v x 20mA is only 0.5 Watts. As the power output is quite low, pwm is more trouble than its worth. A simple amplifier and DAC as suggested above should work quite well.
Hi A simple method is just to generate a pwm where the duty cycle depends on input voltage. Feed the pwm through an optocoupler and use a low pass filter on the output side. Or feed it directely to a microcontroller capture pin. Or use not pwm, but a V-f converter. Optocoupler. Feed it to the microcontroller timer/counter input. The more (...)
I am using STK600 (ATmega2560). I have configured timer 1 for 8-bit fast pwm and system clock is 4 MHz and pwm frequency is 15625 Hz. My wav file is sampled at 3906 Hz and it 8-bit unsigned PCM mono wav file. First I connected speaker directly between pwm o/p pin and GND. This produces humming sound noise in background, it remains as long (...)
LM2576 (52KHz) or LM2596 (150KHz), which one is better for Raspberry Pi power supply (which needs a noise free 5V/2Amps supply from 12VDC (230VAC to 0-12V Transformer)). Only their difference is in pwm. will higher pwm give more noise free output ? Thanks in advance.
Hello All, Can someone point me to a circuit, where I can pro-grammatically using SPI/I2C/pwm etc protocols set current source from 0mA to 500mA in steps of 1mA. may be an IC or even transistor-MOSFET based circuit design. Vin MAX= 24V Vin MIN = 3V Vout Max= 24V Iout= 0mA to 500mA in steps of 1mA .. current managed completely us