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4 votes

Bootstrap circuit for electromagnet drive or sense?

simulate this circuit – Schematic created using CircuitLab This is a typical PWM drive for a relay or valve, but the catch diode D1 can be decoupled from the coil by M2 and M3. During PWM the ...
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2 votes
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Need a circuit for switching 200kHz 24V-36V signal

Almost any small signal bipolar transistors will do. 2N3904/2N3906 have maximum C-E voltage of 40V, so that'll work at 24V with ample margin. For 36V operation, more margin would be nice, so the ...
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2 votes

MOSFET Driver Base and Gate resistors and other input stage for PWM motor control

Choose the switching frequency, for a motor it doesn't need to be very high. Choose the switching time to be slow enough to avoid sharp edges which will make a lot of interference, but not too slow or ...
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2 votes
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Is it safe to PWM control a consumer smart plug or smart switch?

I assume you mean a box fan or oscillating fan or something like that, not the HVAC whole-house fan. Slightly different power level there. Anyway, it'll probably have a single-phase induction motor, ...
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  • 5,356
2 votes

Peak switching power in MOSFET as seen in LTSpice, and reduction using snubber or gate resistor

Yes, this is a fine way to do it, given all the usual caveats of power electronics design, including accounting for stray inductance of the switching loop, peak and average power dissipation, thermal ...
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2 votes
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Peak switching power in MOSFET as seen in LTSpice, and reduction using snubber or gate resistor

but I'd like some confirmation that these transients might be ignored. Absolutely not. They cannot be ignored but, you can easily check to see if the device you have chosen is suitable. Open the data ...
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  • 384k
2 votes

Generate combined sinusoidal waveform (fundamental, 2nd, 3rd...) using PWM

You can synthesize any waveform that you wish using PWM within certain limits which I will enumerate below. Generating a single frequency SIN wave is done by setting the PWM duty cycle on the fly in ...
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1 vote

Control PWM Volume

I believe what the author is trying to say is this: simulate this circuit – Schematic created using CircuitLab The potentiometer is used as a voltage divider, to provide a signal at node X with ...
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  • 8,208
1 vote

Can changing one signals duty cycle in a dual signal PWM create a dead time?

With matched thresholds and load impedance the common way is to use slower turn and fast turn off for each. You choose RC for slow and diode RC for fast. Dead time is the difference in xx0 ns to 1.x ...
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1 vote

Average voltage in PWM?

If you have a simple first order RC filter which removes PWM switching frequency but leaves the DC voltage, it has the correct output voltage, but due to the resistor, the output impedance at DC is ...
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1 vote

Conversion from 0-10V to resistance - Methodology

If you have PWM, you can be synthesizing a resistance directly. All you need is an analog switch, like a 74HC4066 or CD4006. Parallel all switches in the package, and add an external resistance that ...
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1 vote

Cleaning PWM input signal to reduce heating of H-bridge

Between the [14V by 50us] square wave out from the OEM controller and the voltage divider output [5V by 50us] going in to the BTS, there is a lot of distortion happening. The BTS7960 has cmos schmitt ...
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1 vote

How can I change the output pin9 and pin10 into pin5 and pin6?

The program uses high frequency hardware PWM capabilities of TIMER1. The outputs are fix assigned in hardware to pin 9 (OC1A) and 10 (OC1B). There is no option to reassign them to other outputs. Pin 5 ...
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  • 1,924
1 vote

How will a transformer react to a PWM signal?

Depending on the transformer it will react pretty fast on you PWM source. You should take care that you don't introduce an average DC value as this will slowly saturate the core of the transformer and ...
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  • 139
1 vote

Controlling 0-5V from 0-3.3V PWM pin and 5V power

Use PWM. Connect the transistor in a common emitter configuration, with emitter connected to ground, base connected via a 4k7 resistor to GPIO, and collector collected to the cathode (-) of the LED ...
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1 vote

How to switch dummy load circuit on/off with pwm?

Why not eliminate the whole PWM block in your circuit and just add a NPN transistor that can pull down NMOSFET2's gate to 0? You might need to increase the gate drive resistor a little bit to reduce ...
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