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Logic analyzer gives me much more pulses than expected

Not wanting to discourage you... First of all: The logic analyzer is probably not the right tool for the task at hand. Use an oscilloscope and look at what you get. And learn, what Signal to expect. ...
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  • 1,475
1 vote

Using the WS2811 as a vibration motor control

The current the WS2811 sinks is around 16.5mA (15.5mA minimum). PWM frequency is said to be > 2kHz. Probably there is only a sink, no pull-up. Try this: simulate this circuit – Schematic ...
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1 vote

Logic analyzer gives me much more pulses than expected

Logic Levels are usually selected in the menu with some positive threshold. AC Audio signals are bipolar with an avearage of 0V. Thus using a positive logic threshold can add to the errors you are ...
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2 votes

Weird PWM signal if powered by AC/DC source

The funny waveform is explained by the scope probes being connected to incorrect places for what you are trying to measure. You are trying to measure voltage waveform of the LED from the LED terminals,...
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  • 87.1k
1 vote

Mimic a thermistor/variable resistance signal using PWM

I think for the first step, if you want to mimic something, you must know what the original one is. As far as I know, the "signal" provided by a thermistor is normally "sensed" ...
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  • 11
3 votes

Can I power a 20.5V DC motor with a 24V PWM power supply?

The "20.5V, 1.78A" DC motor in your popcorn popper is actually powered by 120 VAC through a heater element and bridge rectifier. This setup relies on the motor having a mechanical load which ...
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0 votes

PWM signal generator circuit does not work in real life

The way to solve your issue is to understand the circuit, estimate signals and check with real DMM measurements. As mentioned in question, I will assume the regulated power supply is 12 V (Vcc). Let´...
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  • 722
3 votes

Reducing 8..32V PWM to 5V PWM

Agree with the answer by Reinderien that usually a microcontroller would be the way to go, but if you're reeeeeally sure that this is all you'll want to do, then its actually extremely easy - if you ...
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  • 4,729
2 votes

Reducing 8..32V PWM to 5V PWM

Your LTC2644 seems very expensive. Economies of scale dictate that this dedicated-purpose PWM-driven DAC is more expensive than a commodity microcontroller with a built-in DAC. Consider something like ...
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  • 2,997
0 votes
Accepted

Driving parallel channels with 1 PWM signal

As far as I understand, if I boil down the question, it will be "can I route one PWM signal to multiple components/devices"? If so, the answer is yes, you can. There are minor caveats that ...
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  • 3,286
0 votes

Can I use a PWM solar controller for charging a 24V battery from a 50V solar panel

You haven't give the panel maximum power point voltage, short circuit current, or operating temperature, but you seem to have the correct panel voltage and battery voltage* A typical 72-cell solar ...
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0 votes

Can I use a PWM solar controller for charging a 24V battery from a 50V solar panel

Presumably, you have chosen a charge controller that is designed specifically to work with a 24V battery or, is configurable to work with a 24V battery. And presumably, it is designed for/configurable ...
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  • 2,285
0 votes

Can I use a PWM solar controller for charging a 24V battery from a 50V solar panel

Usually a PWM circuit include some Inductance to "smooth" the pulsed charging signal. And, usually also include an output current limiter. The Inductance will make the bridge between the ...
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1 vote

Can I use a PWM solar controller for charging a 24V battery from a 50V solar panel

The solar cell won't be operating at 50V since Voc implies zero current draw. You will need a solar panel controller to effectively use the panel. Applying 50V to a 24V battery with no intermediate ...
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  • 6,540
2 votes

Can I connect 12V halogen bulb to a 60V battery?

It would probably be easier to buy 5 20W 12V bulbs and holders, and connect them in series. G4 halogens would work well and the holders are cheap. Then you can test your PWM knowing that 100% on won'...
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  • 2,041
0 votes

Can I connect 12V halogen bulb to a 60V battery?

I like the idea of using a different way to discharge the battery. Read through all of my answer to accurately see the stupidity in this redundant question. The problem is wanting to discharge a 60v ...
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  • 9
2 votes

Can I connect 12V halogen bulb to a 60V battery?

You can, but: Does your circuit has any means of overload protection (e.g. overcurrent protection)? This is important both because something could go wrong and because of the inrush current of the ...
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  • 5,253
2 votes

Can I connect 12V halogen bulb to a 60V battery?

No, your FET is way overloaded A 12 V 100 W auto bulb will draw about 8 amps when at operating temperature. Its cold resistance will be about 1/10th of the hot resistance, so expect about 80 amps when ...
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  • 140k
7 votes

Can I connect 12V halogen bulb to a 60V battery?

Yes it will work, but not the way you set out to do it. The PWM-ing needs to be done by a switching power converter in a buck configuration. It will act as a PWM, and its inductor will smooth the ...
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2 votes

Can I connect 12V halogen bulb to a 60V battery?

The power used by a resistance of R Ohms connected to voltage V is P = V^2 / R So if we raise the voltage from 12 to 60 V, we have 5 times the voltage and thus 5^2 = 25 times the power. So for a hot ...
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  • 2,121
4 votes

Can I connect 12V halogen bulb to a 60V battery?

If the bulb has two filaments forget it, the filaments will arc paralleling the two filaments, causing them to be parallel from there common point until the arc. This overpowers the remaining filament ...
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  • 2,553
5 votes

Can I connect 12V halogen bulb to a 60V battery?

In theory a 4% duty-cycle PWM would give you 12V RMS but the peak currents would be very high and it would likely emit EMI etc to a large degree. Without some kind of mitigation the peak cold filament ...
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5 votes

Can I connect 12V halogen bulb to a 60V battery?

Can I connect 12V halogen bulb to a 60V battery? Do some very simple math to get an indication of whether it would work. At 12V the bulb will draw 100/12 --> 8.3 Amps. The pre-supposes that the ...
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  • 20.9k
12 votes

Can I connect 12V halogen bulb to a 60V battery?

The lamp filament is likely to just blow up. Let's assume for simplicity that the lamp is completely resistive 100W load at 12V. It will thus draw 8.33A, and thus lamp resistance can be assumed to be ...
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  • 87.1k
8 votes

Can I connect 12V halogen bulb to a 60V battery?

Well use 5 of those bulbs in series, that would work. One bulb even allowing for charging variation on the car will be 15V, so 60V is too much. Just to be clear, if you connect that 12V bulb directly ...
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  • 5,111
2 votes
Accepted

Does a demultiplexer affects as a PWM would do?

As you have surmised, the multiplexing affects the display brightness. The common solution is to use a higher peak current, but there is a limit to how much you can do this - refer to the datasheet of ...
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  • 5,352
3 votes

What is the purpose of the capacitor and diode in this fan driver circuit?

Your ideas 1 & 2 for the capacitor are both partially correct. The capacitor, MOSFET, and resistor form a type of variable DC power supply. As the PWM switches Q2 on and off the capacitor and 10 ...
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  • 5,749
12 votes
Accepted

What is the purpose of the capacitor and diode in this fan driver circuit?

Motors are inductive loads. When you apply PWM to a motor, it generates high voltage spikes. The purpose of the diode is to shunt the energy from these spikes back to the supply instead of the ...
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  • 6,650
1 vote

DC-DC buck converter duty cycle issue

A: Non-standard analog requirements for signal conversion with unusually high input voltage wasted are unpopular for mass production targets. But easy to design with a Quad Op Amp and a 24V LDO ...
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1 vote

DC-DC buck converter duty cycle issue

"Shopping questions are off-topic", but there does exist a class of devices that are mid-voltage, low-dropout-compatible, frequency-adjustable DC-DC buck converters. Refer to several of the ...
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  • 2,997

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