New answers tagged power-electronics
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Connecting a capacitor to a voltage supply in series without a resistor
You can't run a simulation like this with ideal components - the operating conditions before and after the switch is closed have to be "differentiable" before and after the switch transient ...
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Why are MOSFETs called voltage controlled devices even though we have to push in charge/current to charge the input capacitances?
The voltage between gate and source is what is controlling the conductivity of the channel. It is the electrical field, not a current that has influence.
Yes, every FET has some specific gate ...
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Why are MOSFETs called voltage controlled devices even though we have to push in charge/current to charge the input capacitances?
You can model it that way if you like. But maybe it's a little easier to start designing a gate driver from the gate voltage requirement, and derive the gate current/charge requirement from that.
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Problem with the output of a synchronous non-inverting buck-boost converter
You are correct, it can't work because the gate driver schematics have an error.
Capacitors C2 and C4 are not correctly connected.
Please fix it by reading the IR2104 data sheet for examples.
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Design Suggestions for an Optocoupler Relay Module
The optocoupler fills no purpose, get rid of it. And as already noted by @Spehro, the MOSFET is completely overkill. It's rated for 49A(!).
The only components you need:
The relay of whatever coil ...
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Changing gate turn off voltage of SiC MOSFET from 0V to -4V
Simple approach is to drive gate through series capacitor C1 with capacitance so with R1 the Vx voltage at the end of Ton falls to about half.
During Toff you see the Vx voltage goes negative and ...
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Design Suggestions for an Optocoupler Relay Module
I would substitute an inexpensive BJT or SOT23 logic-level MOSFET for that enormous TO220 power MOSFET (that isn’t logic level drive anyway). The relay is only 80mA.
R2 is unnecessary with a MOSFET.
...
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Why does my square wave signal from an Elegoo Uno R3 have 3V overshoot/undershoot?
You mention measuring with a gound spring but I didn't see any pictures of that.
Figure 5 shows your probe coming in at the bottom of the board and the ground lead coming in from top of the board. ...
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Best way to go from 5V to .95V to power an FPGA at max 15A
Looking at the Renesas Rad Hard Switching Regulators which has been filtered to select regulators which can supply a maximum of 15 A there are the following which might meet the requirements:
...
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Best way to go from 5V to .95V to power an FPGA at max 15A
A brief search on TI's website reveals a handful of space-rated buck controllers, several of which are capable of output voltages as low as 0.604 volts. In particular, the TPS7H4003-SEP and TPS7H4001-...
- 30.3k
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Best way to go from 5V to .95V to power an FPGA at max 15A
Develop your own buck with a rad-hard fpga as a controller. You could use an external fet that is rad hard and devleop just the spec you need and save power. At an aerospace company I used to work for ...
- 78k
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Best way to go from 5V to .95V to power an FPGA at max 15A
You didn't say what your 5 V current requirement is, apart from your notional concept of generating the 0.95 V 15 A supply from the 5 V supply.
But I think you should generate both your 5 V and 0.95 V ...
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Grounding in power electronics
Based on the information you provided, i'd recommend the following system layout. This only isolates the CAN-Interface for external use.
simulate this circuit – Schematic created using ...
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Best way to go from 5V to .95V to power an FPGA at max 15A
I think you could coerce the PE99155 into making 0.95V by inserting a voltage divider between EAINP and VREF. Check with the Teledyne apps folks. (You did, they vetoed it.)
It's also possible to ...
- 51.1k
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How does this PNP transistor and P-channel MOSFET circuit work?
First consider the circuit without Q4. What remains is Q2, R1 and R2:
simulate this circuit – Schematic created using CircuitLab
With Q2 being a P-channel device, gate potential (\$V_C\$ at ...
- 28.9k
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How does this PNP transistor and P-channel MOSFET circuit work?
Arranging the circuit so as to be more understandable and easier to analyze, although constants are missing, from an analysis by inspection I obtain:
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How does this PNP transistor and P-channel MOSFET circuit work?
AS already pointed out, it is a "current" source ... unless R3 < 200 Ohm.
The current value is ~ 10/160 = 0.0625 A.
- 12k
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How does this PNP transistor and P-channel MOSFET circuit work?
It's a current source. The wire from the drain to GND is virtually a short circuit, but it's current is limited to 0,6V/R1. I bet it would often be more useful to have some load instead of a wire. But ...
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How does this PNP transistor and P-channel MOSFET circuit work?
In principle, it is nothing else than a classical amplifier stage in common-emitter configuration - however, with a pretty uncommon feedback circuitry, controlled by the collector voltage.
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How damaging are inrush currents?
Inrush current from power supplies mostly for led lighting have short duration but high amp.They destroy circuit breaker contacts,switches,timer contacts,contactor contacts and Eazy can trigger C type ...
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Electronically activated circuit breaker
You already have a circuit breaker, right?
They make various types of actuators for these. They're basically an electromagnet that moves a little lever that flips the breaker down. There are also ...
- 72k
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If the current through a welder is hundreds of amps to melt metal, how does the welder circuitry cope
It's not the current per-se, but the heat at the tip - the arc - that heats the metal and forms the weld. The welding rod itself doesn't melt even with the several hundred amps through it. The ...
- 10.3k
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If the current through a welder is hundreds of amps to melt metal, how does the welder circuitry cope
A simple spot welder might have an output like this. The wire on the secondary might be as big as a man's little finger.
simulate this circuit – Schematic created using CircuitLab
- 15k
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How to decide number of layers?
Most designs need only four layers if you need more for current carrying capacity then increase the thickness and get more than one ounce copper weight when you order the PCB.
Typically only high ...
- 78k
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How to decide number of layers?
More layers = more cost, in general.
1 layer: only for the limited cases of mass production where saving
cents per unit counts, or for home-etched PCBs. Often have to use
link wires to join up parts ...
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How to wire two DPDT relays in parallel?
The contacts will not open and close at exactly the same time. You may do some measurements with a digital scope to see if the time differences are small enough for you. But you need a lot of ...
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How to wire two DPDT relays in parallel?
Just to add my 2 cents worth ...
Whether you have 2 relays or a 4PDT, there will be mechanical delays and bouncing during contact.
If your timing requirements, for all connections to be at a stable ...
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How to wire two DPDT relays in parallel?
When paralleling the coils that would be the way to wire it. You would need to make sure whatever is driving the coils can handle the combined current.
Since there will be some slight differences in ...
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What is the difference between voltage mode control and current mode control for SMPS?
The difference is in how the control loops are configured. An oversimplified picture follows:
In voltage-mode control, the voltage is sensed and compared to a reference, and this difference is applied ...
- 30.3k
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Which is the more important switching parameter in MOSFET datasheet? Turn on/off/delay times or Input/Output/Reverse capacitances?
Timing tells you how long it will take for it to switch. So this sets the speed you can operate them, setting maximum frequencies which you can use.
Capacitance tells you how much energy you need to ...
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Checking PCB Layout, Routing Tips and Improvements?
Your board is essentially working at DC.
Therefore:
You can run signals on bottom layer. As long as the plane is not too broken by routing other signals, it should work fine.
Vias do have inductance....
- 137k
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Identification of SOT-23 device
The marking is "01B" in fact if you zoom more and the marking format is typical from Onsemi (dot below and sideways character for traceability).
Then this is probably a LP2301BLT1G / T3G ...
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Can we sell 110V equipment without NRTL certification in a US market?
Yes, you can sell it. The NRTL is enforced at a local level and a legal liability (cover your butt). As far as the local enforcement goes, OSHA requires product testing, so any organization that needs ...
- 78k
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Can we sell 110V equipment without NRTL certification in a US market?
There is no US federal law that requires it. Your customer may require it for insurance or other reasons, or it might be required by city or state regulations.
Consider FCC and other regulations too.....
- 384k
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PCB layout, any improvements to make on the routing?
I can tell what I know:
calculate trace width, use more with some margin and excess for power ones
** switching nodes need thicker traces to avoid parasitic inductance and elements must be close to ...
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PCB layout, any improvements to make on the routing?
A common ground plane is always recommended.
Use copper pour to make the ground plane available everywhere
possible
use a trace width calculator to ensure that the traces can carry the
required ...
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Driving MOSFET with the PWM output of TL494
You can use discrete gate driver that consists from two transistors. I simulated it in LTSpice. The turn-of time (with given resistors) is roughly 300 nano Seconds. Turn-on time is roughly 100 nSec. ...
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Can I convert 12 V DC to 24 V DC using a 2N2222A?
S7-1200 has IEC Type 1 sink inputs so you need to provide current of nominal 4 mA 24 V at the input (minimum 15 V).
One way to do that is with two transistors:
simulate this circuit – ...
- 384k
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Can I convert 12 V DC to 24 V DC using a 2N2222A?
If you can accept inverted logic into your PLC, this would do it:
simulate this circuit – Schematic created using CircuitLab
If you can't have inverted logic, use two:
simulate this circuit
...
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If the chassis is at high potential and a human touches it, will he get shocked? The proposed circuit is for the cancellation of CM current
It seems to me that this is in an automotive context, where the chassis ground does not necessarily correspond to earth, and a real earth reference might very well not exist if you are not hooked up ...
- 16.1k
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State-space average model of non-ideal buck converter
i myself struggled with this too.
I will show how to derive the equation for a system only containing the ESR resistor for the Inductor and capacitor, as these are the parts bringing some ...
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EMI filter attenuation requirement for a buck converter given EMI compliant AC-DC converter
It's a peculiar thought, to consider a power supply as a two-port:
simulate this circuit – Schematic created using CircuitLab
A power supply is generally a very nonlinear system, particularly ...
- 27.3k
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Can anyone help me write a program in Python to output 5V from a USB port to control a relay?
Perhaps the simplest way to get single bit I/O from a PC is to use a USB serial lead (they are all over AlliBayZon for a few $£€), and the pyserial library (not serial, that's something else) with ...
- 162k
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Do we really need the metallic chassis to be grounded if it is coated with a non-conductive paint?
Yes, the paint would act like a capacitor, and yes, it would possibly break down and arc to the person touching it (depending on the paint properties, of course). When AC live is at peak potential (...
- 28.9k
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Do we really need the metallic chassis to be grounded if it is coated with a non-conductive paint?
Most metal chassis use screws or pop rivets to fix them.
Either a screw hole will not be painted so the threads are not blocked, or the screw will cut through the paint when inserted. Similarly pop ...
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