New answers tagged power-supply
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Brushed motors can run without a controller, higher voltage will allow them to run faster, a BLDC motor has to be used with a controller and that determines the speed, while the voltage determins the maximum speed possible.
By using a BMS and also setting a max current limit in the BLDC controller.
Depends on the BLDC controller, you set the max power limits ...
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That is most likely transformer coil whine. The windings vibrate along with the changes in the magnetic field.
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In general for switching power circuits of some fixed power level, a higher operating frequency allows for smaller magnetics and smaller input and output filter components (inductors and capacitors).
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This works fine on the Arduino using a CNC shield from USB 5V with 12V power or laptop charger 19.5V with good common grounds.
However if the signals are on long cable, you may experience errors on Data if the charger is connected from Charger Common mode noise.
If you sequence power while connected the unpowered digital interface may have problems if un ...
answered 6 hours ago
Tony Stewart Sunnyskyguy EE75
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1
I am attempting to start u12 on the input voltage, then when the
regulator starts up, to use that to turn off Q1, changing the input
from the 24v line to the 15v line. However, I don't think that would
work
You are correct, that won't work. The FET will be turned off when the 15v rail is low and turned on when it is up - the opposite of what you want. Also ...
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You shouldn’t need an ideal diode on the unit-to-unit link, just one on each of the USB inputs and have the +5V bus shared between units. There might be a concern with connecting the grounds to each other though.
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I had the same fault on Falstad’s simulator until I debugged the circuit.
Remember the rules;
Investigate
Measure everything relevant
Compare with component specs
Continue until error
Analyze
Fix
Validate if not Repeat
So after walking around each transistor , I discovered for currents < 1mA then hFE sensitivity is very low. After all there is not ...
answered yesterday
Tony Stewart Sunnyskyguy EE75
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2
The simulation does not show a sufficiently accurate result either:
This is a more accurate version (improved Wilson current mirror):
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I doubt that your setup is going to work. I see several issues:
The USB-C-to-HDMI adapter most likely expects a power supply of 5V on VDD. If your YZ12PDN board negotiates 12V, it will likely kill the adapter.
Video data is transferred using USB-C Alternate Mode. In order to activate it, it needs to be negotiated via CC1/CC2. This is in conflict with ...
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Current sharing on redundant DCDC converters requires accurate voltage matching and accurate current detection with share splitting communication between the supplies. Diode Or SHARING often requires a preload of 5% to 10% to achieve stability with no loads from my experience as resonance can occur from each driver sharing the same current sense see each ...
answered yesterday
Tony Stewart Sunnyskyguy EE75
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0
This is a non-redundant 400W supply with primary load = 12V and other smaller load voltages. The Delta supplies > 1KW appear to be redundant with dual 12V outlets.
i.e. All wires are common for V+,0V.
Generally, PC PSU's regulate off 5V and use tight magnetic coupling with winding ratios to generate the other voltages. But in Zeus servers the main load ...
answered 2 days ago
Tony Stewart Sunnyskyguy EE75
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2
Your understanding of the setup is wrong,
A single resistor will not help, all that can achieve is current limiting which would be I = V/R = 21V / 3.9R = 5.4A @ 21V. This would not change the voltage in the slightest.
You would need to create a voltage divider to drop the voltage, to do this you would need something like a 3.9R (R1) & ~6R (R2) to get ...
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Assume that the core is of infinite permeability (ideal magnetic material).
g=0,113mm
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We could just plug numbers into the formula, but it's more instructive to do it from first principles. Then if you forget the exact form of the formula, you can re-derive it.
You've already suggested some numbers for turns and pole area, so let's do it for a specific airgap as well, say 1 mm. Inductance is inversely proportional to it (assuming perfect ...
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The power supply cannot adjust itself automatically to what the device expects. It can adjust the output voltage to try to compensate for the voltage drop on the wires based on current draw though, but the original is only rated 2.5A and the replacement is rated up to 4A. Get a proper 18V replacement, with 2.5A or more current rating.
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You can use an LM2596 in an inverting configuration.
According to Fig. 19, maximum load current should be around the 1A level.
There are probably some similar LTxxx products that are more expensive and better in this application. Initial start-up surge tends to be quite large in this configuration, hopefully your 4A capability will handle it.
Edit: For ...
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An alternative to your proposed approach is the "online UPS" strategy:
Connect the loads to the battery.
Connect a mains-powered battery charger to the battery.
Connect a solar battery charger to the battery.
And that's it — no switching devices at all. It's the same way a car battery system works — there's one circuit that the battery, charger (...
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Safety is a concern--moisture ingress can conduct dangerous AC voltages to the outside of the case. There is probably also a slightly lower incidence of tampering when people know they can't easily reassemble the device.
The big driver, though, is cost. Adding removable screws involves multiple operations per screw, whereas sonic welding is easily ...
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simulate this circuit – Schematic created using CircuitLab
Using a DVM to detect +V on the switch. Connect both to allow either switch to activate both or add a 3rd switch externally.
answered Aug 10 at 18:59
Tony Stewart Sunnyskyguy EE75
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0
I solved the problem! It seems to be that I didn't isolate the wires leading from my PCB to the gearshift and screen thats what caused the interference. The voltage spikes radiated from one wire to another.
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Should this be your schematic, it would be quite okay.
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Data centers use 3 phase because utilities will insist on it for the amount of power they use. If they were to give them single phase, it would cause a severe imbalance of the 3 phase utility transmission lines. Single phase service drops are generally limited to 167.5kVA (around 800A) maximum, most data centers use thousands of amps.
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The real problem is that the stresses involved with achieving say 10% ripple voltage with split phase is that the charge current can only operate during 10% of the time so its decay period of 90% of the time is the actual discharge load current while the charge current is the load plus the charge current to reach diode peak voltage. this results in the ...
answered Aug 9 at 1:53
Tony Stewart Sunnyskyguy EE75
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0
if the board layout is the same as the schematic layout then current to C! flows through that trace. if there's a lot of ripple that could be a high current. Also current from P1 flows through that trace.
3
We were offered 120V or 208V at at one US data center, so three phase is available.
Six pulse rectifiers are efficient at making DC, but powerful DC circuits are hard to manage once you exceed the working voltage of your typical arc welder.
Ordinary switched mode power supplies start with rectifier followed by a a power-factor correction circuit, these will ...
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This is a device-specific question as different laptops will have different Li-ion cell structure. Smaller ones (13"-14") have 2S flat non-removable Li-ion cells and general 15.6" versions will have 18650 cells stacked 4S, 6S etc. Hence it totally depends on which make it is and the purpose of the machine. In your case, this MSI laptop (MSI ...
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I have a similar Dell laptop power supply (CN-ON6M8J) and connected the blue wire to the white wire with no problems. It puts out 19.64 volts. I got the same reading before I connected the blue wire to white. But then I accidentally shorted the white and black wires and the power supply shut off and its LED went out. So I tried touching the blue wire to ...
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Do you want the external battery capacity the same or much bigger than the internal battery pack. If so, then compare your choice to the internal one which has a spec of 41 Whr.
You can round the battery cell voltage nearest to 19.5V which is now a standard for laptop chargers. Consider the cell voltage as 3 to 3.7 so a 6S=18V min. is better.
But it should ...
answered Aug 8 at 12:34
Tony Stewart Sunnyskyguy EE75
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0
A lithium booster pack for automotive use could give you enough power. Many only have a protected output, but some have a switch for full 12 volt unrestricted output. In my case, with a smaller unit, I added a 20 amp inline fuse and an output connector. I use it to provide test power to security cameras while troubleshooting. My unit is rated at 7000 joules. ...
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12V 12A or 144VA is about the storage capacity of 3 lead acid car batteries for 1 hour!
Lithium secondary batteries must consider the cost to achieve this performance of expect range Volumetric energy density: 250 to 680 Wh/L
Consider that batteries are rated for 20h capacity and Peukert's Law dictates that will decrease with reduced discharge times.
As with ...
answered Aug 7 at 22:52
Tony Stewart Sunnyskyguy EE75
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1
There are only a limited number of battery chemistries and each one has its own voltage so there are only a limited number of voltages. Also, battery voltage drops as they get discharged so you won't find exactly 12V. Search radio-controlled hobby websites.
The most likely chemistries available to you, in order of increasing cost, increasing performance, ...
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When you're regulating based on current you are actually converting that current to a voltage. This is done either through a shunt, a current transformer, or some hall effect sensor. You then end up regulating THAT voltage in the same way you would regulate your output voltage.
It really goes deeper than that depending on how you're regulating, but for ...
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80W motor with current of 40A and supply of 24V? Makes no sense at first look, but this 40A stall current is measured at speed = 0 (rotor locked), this is not a working range of the motor
Your driver works as buck converter, so you don't need 2 x 40A x 24V supply power. You should use the nominal current of the motor, not the stall current for proper supply ...
-1
the jack plug is L shaped and won't fit through my speaker stand
Presumably a straight jack will work so, get a short adapter cable like this one: -
Or this one: -
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As long as it's 18V, >= 1.3A and has the same plug polarity, you can use it. You can also cut the jack off and put a new one on (or just push the cord through and re-attach it).
If you do cut the end off, I'd recommend using butt-splices (if you can't solder/shrink tubing) to put it back on, or get an end with screw terminals:
Just pay close attention to ...
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Have you heard the expression "cut your coat according to your cloth"?
10kV transistors don't appear to exist, no. 1kV seems to be just about feasible with present technology and you can buy bipolar and IGBT transistors with that rating. They need appropriate cooling and sharp switching times to avoid overheating.
using 1A and a 10Ah battery this ...
1
So, the question is whether the supply is operating correctly or not.
A practical answer:
The LM7812CT requires a voltage difference of at least 2VDC across its input and output terminals. This voltage is called Dropout Voltage. So the minimum input voltage for proper operation should be \$\mathrm{V_O+V_{DROP}=12+2=14V}\$. Since the input voltage comes from ...
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Using power formula for DC circuits: Power [Watts] = Voltage [Volts] x Current [Amps]
If you are stuck with USB 2.0, then you are limited in how much current you can draw by the USB 2.0 specifications, which is 2A @ 5V, for a total of 2 * 5 = 10W.
So, you then need to increase the voltage using what's called a boost converter, which will boost the voltage ...
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A similar product appears to have a 12V, 2A output:
SEDNA - USB Type A 5v to 12V 2A DC DC Converter with 9 x 90 Degree Adapter Jack https://www.amazon.co.uk/dp/B07952G6KT/ref=cm_sw_r_cp_apa_i_EDrlFbDWTFCZ8
2A seems to be more than enough for your LEDs.
Would have commented but not enough reputation.
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I stumbled on this thread last week and was surprised the following fix didn't get mentioned: with three more resistors and one power supply connection change, the circuit can work as originally intended.
As previously noted, the LT1719CS8 output stage cannot operate between +/-5V. But it can operate 5V single-supply, including from 0V to -5V. So with the ...
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13V is a very unusual voltage for a USB charger. The only way to achieve it within the USB standard is to implement USB Power Delivery 3.0 plus PPS (Programmable Power Supply), which allows to change the voltage in small increment. Even then, the maximum voltage would either be 12V or 20V.
This charger could still be safe if:
It initially delivers 5V only.
...
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I solved the issue.
The pads of one of the switching transistor were lifted. I repair these pads and SMPS worked fine.
Thanks for the support. @winny @RohatKılıç
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You have solved 'sparking at plug-in' by delaying mosfet 'turn-on'.
Likewise you could avoid 'sparking at plug-out' by first turning off the mosfet and then plugging out the load.
You would need to wire an additional switch to the controller.
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Your question relates to two types of regulator circuits - 'Series' and 'Shunt'.
In a series regulator circuit the load voltage would be maintained by dropping the excess voltage across the series transistor.
In a shunt regulator circuit the load voltage and that maintained across the shunt transistor would be one and the same.
Generally, series and shunt ...
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"Design a power supply with a linear regulator and bypass transistor to regulate voltage to 12 volts and supply a maximum current of 5 amperes."
The solution is presented in the 78xx series datasheet on page 20.
I want to be able to design a linear regulated power supply but with a bjt near the load, ...
No, you want to use a BJT to boost the ...
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