Hot answers tagged

3

Always match the voltage of the power supply and the voltage of the fans. Wire fans in parallel. Never wire two motors (such as fans) in series. When one stalls, the other one will see twice the voltage, damaging it, especially if it has electronics inside.


3

Answer The BLDC motor is in general easy to connect, and easy to test, as summarized below. (1) You connect power, (2) You input PWM signal, (3) You leave direction wire disconnected, (4) You leave FG (motor encoder signal) disconnected. BLDC happily turns, and that is all. But also see the warning in Appendix C. References BLDC JGB3525 Motor - Aslong ¥80 ...


3

The module you have purchased does not provide a varying DC as you seem to want. All it does is to provide a pulse width modulation signal at higher voltage and current than the input PWM. The module you have uses two MOSFETs. Yes, you could simply use a MOSFET in place of the module you have. You don't need a steady DC to power your LEDs. The pulsing ...


2

The D2 diode charges the L2 inductor and then as the power removed from the L2 its voltage reverses and passes thru the D2A diode to recharge the C5 capacitor. Which appears to be a typical step-down. Actually, the whole power supply is a 2-switch forward converter (a.k.a. double ended forward converter): ImgSrc: Researchgate (Jindrich Windels) As can be ...


2

In short, unfortunately, you really only have 3 PWM channels, not the 4 that you wish that you had. The H and L are a complementary output pair with dead-time transition to prevent short-circuits. The H and L pins (PWM1L1 and PWM1H1) are complements of each other, for working with high and low MOSFET's, for motor control, or buck or boost converters (or ...


2

Here's how you would use a resistor potential divider to generate a TTL level "high" of just under 5V to apply to the grey PWM control input of the fan: simulate this circuit – Schematic created using CircuitLab Since the signal remains high 100% of the time, this is equivalent to a PWM duty cycle of 100%, and the fan should run full-beans.


1

While the 6 PWM outputs of that microcontroller are not totally independent, it also has 4 ‘output compare’ PPS pins that can be configured for PWM. You should still be able to use this microcontroller for what you want to do. See section 16 of the datasheet -


1

Check that pin 7 actually measures 0V right at the chip pin - making sure that there is not a loose connection on the ground due to the sometimes unreliable solderless breadboard. It's also possible the chip is damaged or it is not a CD40106, but it's unlikely that damage would affect all the inputs at once.


1

The buck converter will work in most cases. If you are concerned about reliability or EMC or losses then the series scheme has some merit. You should not just connect in series. These brushless fans take current in ripply pulses. When you measure this with a scope and a 1 ohm burden resistor you will see. Electrolytic capacitors of 470 microfarad will deal ...


1

Not sure what this circuit is supposed to do. It's certainly not a practical dimmer. Maybe it's intended to cause some modulation of the light from the beat frequencies of the 555 and the mains. It's hit and miss over any given half cycle whether you'll get the triac to turn on or not, but only integral half cycles get passed. Or maybe someone just stuck two ...


1

The zener will be useless as you seem to be powering the NE555 with 12V, so you don't need any protection for FET gate.


1

Inspired by this source video: https://www.youtube.com/watch?v=QMAgD9SS5_E I needed two out of phase PWMs with complementary PWMNs (plus dead time). I used TIM1 and TIM8 as well, TIM1 is master, TIM1-CH1 has PWM & PWMN output, TIM1-CH2 as a trigger source, to trigger TIM8 as slave. TIM8-CH3 has another pair of PWM & PWMN output. By updating the ARR ...


1

If I understood correctly, you need another approach for making complementary output with dead zones. If you configure timer CC modules as opposite polarity PWM, you will have synchronized complementary outputs. If you configure the timer with center aligned mode, you will have the ability to make dead zone with manual intervention.


1

The only answer I can come up with is that there is no easy answer. You may empirically "calibrate" your system but even that depends on many aspects you probably have no way of measuring or estimating. Just to name few: Motor load (Is the car driving uphill, downhill or on a flat surface?) Acceleration rate Friction Power source (battery) ...


Only top voted, non community-wiki answers of a minimum length are eligible