New answers tagged

0

Start by trying a fully integrated bridge assembly such as the BTS7960, available for less then $10.00 Delivered. It should do a good job for you and yes it is a bit of an overkill but it is also cost effective. Test it in your lab and be sure it will do what you want. If it does then you can get the individual parts and build it on your PCB. I prefer ...


1

At least you could simplify it: simulate this circuit – Schematic created using CircuitLab buck mode: M1 turns on for specified duty time with regard to stepping down ratio M2 synchronously switches on while M1 is off M2 also switches off if a back flow is detected with comparator CMP2 boost mode: M2 turns on for specified duty time with regard to ...


1

IR2113 is a bootstrapped high and low side (half H-bridge) driver. Your MOSFETs are both low-side. Consider using low-side drivers instead. These are basically inexpensive high current buffers, to push enough current into the gate to switch quickly. But it may still work. Here's the internal schematic of the driver: The top driver is normally bootstrapped, ...


0

IR2113 is used for a push-pull topology as an half bridge. If you use digital level MOSFET, you can drive directly your switches. IRLZ44N (55v-47A) may be suitable or better STP40NF10L (100v-40A). The output will be a DC voltage in your initial schematic. Be careful with the connection to the earth.


0

DC Motors have a dynamic resistance that spans typically 100:1 (+/-20%) . This means locked rotor or start current at full voltage is about 10x rated current and no load is about 10% of rated load current. So to test your Bridge, it must have the ability to absorb the \$I^2R*t\$ during initial start well within operating temperature without melting the FET ...


0

you could block the rotor, that maximizes the current as there would be no counter emf on the winding, however, you may want to be careful as it may very well overheat even if the motor is rated for that current as, the fan that motors typically have won't be spinning. an other option is using rheostats to simulate the load. Adding weights won't really help, ...


0

1- You should think of terminals and connectors while designing your PCB, you should also think about the width of traces since those traces will support high current (8A per every trace) and I'll give you an example: Every battery pack will be connected to the PCB by a XT-60 connector. Then connected by traces with largest width possible (say 10mm) and then ...


1

Since you have two PI controllers in there it only makes sense to tune them separately, by setting, in turn, \$i_d\$ to zero, and then \$i_q\$ to zero. You will need fairly high bandwidth in order for it to respond as fast as possible to changes in current, while the voltage loop (for the DC link) is usually slow, maybe even 10x slower. And the two paths ...


1

I want to make a DC/DC supply that outputs between 10V and 28V from a 12V input so you're probably making a SEPIC to get that range above and below the input voltage simulate this circuit – Schematic created using CircuitLab R1 only ever sees a small voltage, so you could use a digital potentiometer there or even a resistor ladder DAC. another option ...


0

Plan to use a timer IC or microcontroller to implement the delay and a solid state relay to turn on the pump. It seems like you're looking for a design that uses a power switch at high voltage and non-contact sensing; instead think about having the power switch on a low voltage DC circuit or powering the low-voltage DC circuit from the power you've just ...


0

Because your output voltage range is both above and below the input voltage, you will need a true buck-boost circuit. Linear Tech (now a part of Analog Devices) excels in this field. A key characteristic of the circuit is that it has four MOSFET switches so it transitions smoothly from synchronous-buck to synchronous boost as the output voltage increases. ...


1

Linear makes an IC for this that I've used: It is a current source/sink and can be used on any DC DC converter with a voltage feedback control and a voltage feedback range from 0.4V to 2V, it's only 7-bit so it doesn't give great granularity on voltage control, but it lets you adjust levels and it has two gain modes. Another thing is if you wanted to roll ...


0

It was a very poor class-A inverting amplifier that produced a very low max output power but wasted a lot of power making heat even when it was not playing any sounds. I increased its output power 58 times but it is still very low.


0

ESR is a compromise between low output impedance and preventing oscillations. At frequencies between a few 100 Hz and 10s of kHz the ESR of the output bulk capacitors is often the deciding factor for power supply impedance..So lower is better in this regard. However in SMPS you also form an LC output filter which can oscillate with too low series resistance. ...


0

Electrolytic capacitors are used to smooth the voltage rippleson the input and output of a smps. Due to this, a ripple current is imposed on the capacitor. This current causes heat rise due to losses caused by the ESR. Therefore, for a given ripple current, a lower ESR value will cause less loss. Electrolytic capacitors have a liquid electrolyte. Heat causes ...


0

Phase shift and time delay are two different things. At audio frequency, that is in the kHz range, the output voltage to input voltage propagation delay of this circuit is zero. You might have propagation delay effects if the wires were 1 mile long. The BJT does not introduce propagation delay unless the input signal is in the GHz range.


0

I’d be choosing a bluetooth module with Arduino support so you can load your own code. Something with a nrf52 or suchlike. The nrf52 is a microcontroller with on chip bluetooth support. Nordic have their Thingy unit as an example. Depending on your exact requirements and skill level, Espruino or Micropython might ease the learning curve and speed your ...


0

Do this (assuming that your loop is controllable and not unstable) : Open loop method to tune a PID controller Freeze the PID output Make a step change on the PID output (MV) in order of 3-10%. Step should be sufficiently big to see its effect on the controlled process variable (PV) Log response of MV and PV and fit the model parameters of a First Order ...


3

What is the purpose of this sense pin in dual MOSFET package? It is used as a Kelvin connection for the reference voltage being used to drive the gate to reduce undesirable effects of lead inductance due when sharing gate drive and primary current flow through the same pin. The dI/dt of the primary current across produces voltage drops across the true ...


1

Isolation is your tool to make sure crazy currents don't trigger digital signals or mess with analog signals. Since it's "just" a drone, you don't need isolation same way it's required in industrial applications. So to your question, if you can be sure you design the current flow such a way you don't get grounds bounced each time a motor is turned ...


1

The power must be supplied to all from the LiPo, with step down voltage regulator on controller board... Will ground bounce be induced if the ESC connectors are on one board, and the controller board is completely separate? If they are all supplied from the same power source than they cannot be completely separate. To prevent problems due to current flowing ...


1

For cost reasons you don’t choose a high oz Cu board then etch away most of the Cu that you paid dearly for. You choose the wire gauge needed by the area and length for minimal Voltage drop and inductance by using jumpers, busbars similar with Litz wire for cables or twisted pairs. Next question?


1

How do you dictate the copper oz pour/width that would meet a high amp requirement? It really depends on how much heating your design can tolerate and what temperature the designs "ambient" temperature will be. There are dozens of calculators (this being one of them) that can help you calculate the temperature rise. With at 40C rise and 40A that ...


2

As Neil_UK's answer points out this arrangement is not good for power supply because it will change the resistance value if connected element is not high impedance element. For power supply, you can use linear regulators like 7805 for 5V supply. You can also find 3.3V version of linear regulators. The higher voltage will be dissipated by mostly heat for ...


3

So actually if you take Vout, connect it to the + terminal of a device, and the - terminal to GND, the voltage of this circuit will be dependent on the resistance of the device. So what is this arrangement of voltage dividing good for? It's good for driving very high resistances, where the load resistance has no significant effect on the output voltage. It ...


2

A classic burned component on a hard drive PCB which looks like a diode, is a TVS diode. Once common cause of such damage on 3.5" HDDs is where someone has managed to reverse its 4-pin "Molex" power input connector. In that case 5 V is connected to the HDD 12 V power input, and 12 V is connected to the HDD 5 V power input. Whatever over-...


0

I usually use 1/2VI as an upper bound for power and then find the average switching time. This is calculating the worst case power value which what most designers care about (and is easy to calculate); if the power is too much for the temperature rating of the package, then a new design is needed (either more thermal heatsinking or a different package). If ...


2

You cannot get the exact phase-ground voltages because the delta connection removes the zero sequence component. For example, below I show the symmetrical component equation for a & b phase voltages in an abc rotation system, $$V_{an}=V_0 + V_1 + V_2 $$ $$V_{bn}=V_0 + \alpha^2V_1 + \alpha V_2 $$ So, the a-b voltage will be, $$V_{ab}=V_{an}-V_{bn}$$ $$...


2

The Q is given by the parallel resistance of the coil. so simply add a much larger high quality foil cap in parallel to the coil to bring down it's resonance frequency to a measurable range. And determine the impedance at resonance.


1

Best way to measure Q of very high Q coils is to use the venerable Q Meter. Two typicl examples come to mind, the Boonton 260 which is a late 1950's box or the HP4242A. Both use high impedance voltmeters. You simply place the inductor across the terminals and tune the internal variable cap until the meter peaks, then direct read from the meter the Q. The ...


0

You had better use a 5V 1k pullup resistor on the TTL 7404’s to speed up the rise time past 2.5V as it is not a rail to rail output like HC04’s. Look for reactive parasitic feedback in paths nearby. That may cause ringing. You can use your finger of some sponge fragment and or tiny magnetic material tip nearby to make it worse, then you can see the ...


0

One of the most enduring myths about electricity is that it works like water flowing through a pipe*. The power adapter isn't like a water pump that needs to be regulated depending on how much water is being consumed. Rather, it just provides a steady voltage up to a certain maximum current, and the internal laptop charge circuitry decides how much current ...


0

There's a good article in the April 2021 issue of IEEE Spectrum (https://spectrum.ieee.org/semiconductors/materials/gallium-oxide-power-electronics-cool-new-flavor) that addresses this issue, though in the context of Gallium Oxide semiconductors. Here's what I gleaned from that article (note, I am not a device physicist). Most of the advantages of materials ...


1

Perhaps the most obvious difference is that GaN is a direct band gap semiconductor, whereas SiC features and indirect band gap. GaN will therefore be preferred in light-related applications, such as LEDs. GaN devices often achieve higher switching frequencies compared to SiC, which in case of SMPS means smaller inductors/capacitors for the same power. I ...


0

the ugliest hack-job, old wires soldered 3 to 5 didn't work, then added 1 to 5 so in the end pad 3 and 1 to pad 5 WORKED!! never would have expected it to function. its messy but it does the job Edit (relized i solded 2 to 5 not 1 to 5. It works, but after pad 2 there is the inductor L16 and the D2 diode, there will be a voltage drop in the diode, so your ...


2

You can make it work but be aware of the role of jack pins 3 and 5. When the plug is not inserted pin 3 is connected to pin 2 and pin 5 is connected to pin 4. When the plug is inserted these connections are broken. As for the damaged pads, you can use an xacto knife to carefully scrape away some of the solder mask. This will expose the underlying copper area ...


1

Your question is not clear. However if you designate an antenna at a certain frequency (2.45 GHz and 900 MHz), it is assumed these antennas are resonate at those frequencies. That means they are designed to be most efficient at those frequencies. Thus if you transmit at 2.45 GHz, the 900 MHz antenna will receive thoses signals but output a much lower level ...


1

The internal reference is 2V, so to get output voltage of 1.8V you need to connect FB directly to the output and use either a precision external reference or a resistive divider to apply 1.8V to REFIN. Per the datasheet, Pin Description table: FB Feed back Voltage-Sense Connection. Connect directly to the positive terminal of the output capacitors for output ...


2

Have a look at the pin descriptions on page 10 of the datasheet: So you can use a voltage divider with REF to establish 1.8V on REFIN and then connect the output of the converter to FB. The application circuit on page 11 shows an example of this: When the MOSFET is OFF, the voltage at REFIN is about 1.5V and when ON around 1.05V.


3

When selecting mosfets for power electronics it's hard to tell which 'bulk' material properties will translate into properties that engineers care about because it isn't just the material properties, but also how the mosfet is constructed. Source: https://spectrum.ieee.org/semiconductors/materials/gallium-oxide-power-electronics-cool-new-flavor GaN has ...


0

I suspect the answer wanted is that the TRIAC 'should be' more expensive because it is a more complex device that 'should be' more difficult to manufacture. Looking at the theoretical construction you would think so, because it appears to be made from 2 SCRs wired back-to-back. In practice however the entire device is built on a single slice of silicon just ...


2

A triac is the most complex, so this is probably the answer that your instructor wants. However, as people have said in the comments, other factors could easily be more influential. Example: for current ranges used in household dimmers, huge quantities are produced and this may cause the triac to be the cheapest.


2

PCBs are treated by the IEC 60950-1 "separately" as for solid insulation, that is when the path of discharge passes through a solid object (i.e. the substrate / prepreg). The main requirement is that the thickness must be >= 0.4 mm: that barely fits the 4-layer pcb with standard thickness of 1.6 mm. A simpler 2-layer PCB is evidently ok. Table ...


2


1

If you have (say) an isolated 25kV supply with two terminals, positive and negative, you could in theory touch either of them and feel nothing. It's only when a path exists from one terminal to the other via your body that you will be fried. Neither of those terminals cares about "ground" - just the other


1

No, current doesn't particularly want to travel to ground. If you have an isolated power supply, and connect one terminal to ground, the current flowing will be very small.


3

Would a short produced from any kind of isolated power supply would like to travel to ground? simulate this circuit – Schematic created using CircuitLab Figure 1. In (a) a L-E fault will cause current to return to the supply through the earth and, if high enough, will blow the fuse. In (b) there is no ground return path, the faulted wire will be ...


2

"Can a short produced from the isolated power supply would rather like to travel to a conductor that is connected to ground" is this a valid statement? It is not syntactically correct, so it can't be valid statement. What you might mean is whether a short from an isolated power can case current to ground? No, in an ideal situation it can't. In ...


3

SiC and GaN address different sectors. GaN is an often superior replacement for Si superjunction MOSFETs in the ~600V segments (mains switchers / rectifiers). As an example you could read about Google's Little Box Challenge from 2015, which was dominated by teams using GaN technology. SiC is best for higher utility voltages that GaN can't (yet?) address. I ...


0

ALL the paralleled solar panels (9 of them) must be in full sunlight. A shaded one will draw some current from the remaining ones that are in the sunlight.


Top 50 recent answers are included