16
votes
Is it recommended to set the current limit on a bench power supply by shorting it?
It's recommended to read the manual for the procedure. Did you read the comment in your link that claims the manual says to set the voltage to 3V and then short? I can't confirm it's the same model in ...
- 379k
13
votes
Accepted
Is it recommended to set the current limit on a bench power supply by shorting it?
Is this the correct way to set the current limit?
There is really no other way if you don't want to be tweaking the current limit while the load is attached. And that would be not a great idea for ...
10
votes
Accepted
Derating of C0G DC block capacitors with applied DC voltage
There are two significant misconceptions from your colleague:
Type 2 dielectrics, in general, need voltage derating, or some [fixed] ratio thereof.
All ceramic capacitors, in general, need derating.
...
- 24.3k
7
votes
Is it recommended to set the current limit on a bench power supply by shorting it?
Good ones will happily regulate current even into a short circuit and the current limit you set will not change even if you move up to near max voltage.
One of mine doesn't. Burned some LEDs learning ...
- 13.4k
7
votes
Is it recommended to set the current limit on a bench power supply by shorting it?
Low-cost power supplies like this often have a large capacitor across the output terminals, so if you short-circuit it when the output voltage is high, you'll get a spark as the capacitor discharges, ...
- 1,327
6
votes
What connectors do these power supplies use?
For the Eltek SMPS 1000, found the Eltek SMPS 1000 user manual posted on-line. This contains details of the pin-outs of the connectors, which should allow you to identify the mating parts:
- 624
6
votes
Why do my MOSFET keep blowing up saying the gate-drain voltage exceeds its rating?
Why do my MOSFET keep blowing up saying the gate-drain voltage exceeds
its rating?
You are rectifying and smoothing 220 volts. This produces a DC voltage of over 300 volts and, you are hoping to ...
- 437k
6
votes
What connectors do these power supplies use?
Eltek SMPS 1000
Those are DIN 45612 board-to-board array connectors.
Left: Type H. Mate: Harting 09062152854222
Right: Type MH. Mate: Harting 09062316821
{Digikey}
- 17.5k
5
votes
What connectors do these power supplies use?
EMERSON Energy Systems BML 231 002/1
Those are Anderson Power - Powerpole connectors.
https://www.andersonpower.com/us/en/resources/PowerPoleResourcesPage.html
Measure the width of each pole to ...
- 17.5k
4
votes
What connectors do these power supplies use?
The Artesyn PSU-32-AC is part of a Ericsson GSM system. As far as I can tell, these PSUs are connected to the Internal Distribution Module (IDM) which has the ...
- 2,741
4
votes
Does turn-on and turn-off delay cause MOSFET switching loss?
As per this doc, there are no switching losses during delay time, but it can cause gate driver losses.
- 2,621
4
votes
Derating of C0G DC block capacitors with applied DC voltage
C0G and in general class 1 dielectric ceramic capacitors don't derate neither with temperature not bias voltage, class 2 on the other hand do, the lower the number of that dielectric the higher the ...
- 915
4
votes
Derating of C0G DC block capacitors with applied DC voltage
Murata says in their ceramic cap FAQ that C0G caps have no DC bias characteristics.
So either the caps need to be derated for other reasons, but at least they don't need derating due to capacitance ...
- 130k
4
votes
Accepted
MPQ4470-AEC1 Layout guideline clarification
No, the datasheet does not say only "close". What is says is "as close as possible". Therefore, if it is possible to move a capacitor closer, then it is too far away.
The goal of ...
- 18.5k
3
votes
Does turn-on and turn-off delay cause MOSFET switching loss?
No, it doesn't, and you can see in the diagram the phase difference between the voltage rising on the gate and vds, the losses you have on a transistor are the rising and falling edges where you are ...
- 915
3
votes
What is the role of an MKP capacitor in the input of this SMPS? What happens if I remove it?
That's an X2-rated capacitor. Those are intended to die by shorting (and in that way taking out a fuse), so you should check its resistance to see whether that is what it did.
They usually buffer ...
- 2,664
3
votes
Accepted
What is the role of an MKP capacitor in the input of this SMPS? What happens if I remove it?
For reference, a typical schematic can be found on page 13 of this datasheet (similar but unrelated part); or on numerous appnotes, or schematic collection sites.
https://www.onsemi.com/download/data-...
- 24.3k
3
votes
Two switch flyback converter MOSFETs voltage stress
voltage source of 1000 V is applied to the primary side, does the high side and low side MOSFETs share the voltage (500 V +500 V) between them, like LEDs connected in series.
No, they don't.
Look at ...
- 27.5k
2
votes
Does turn-on and turn-off delay cause MOSFET switching loss?
Yes, but not in a useful way.
Two basic reasons:
Loss is not, in general, proportional to these delays.
I assume you were thinking, let's take the triangular power dissipation waveform between I rise ...
- 24.3k
2
votes
Accepted
Calculating inductor value for my buck converter
The determination of the buck inductor value - its inductance - operated in continuous conduction mode or CCM is a fairly simple exercise. Once you have the main operating parameters in hand like ...
- 20.5k
2
votes
Accepted
Why is the output voltage (without capacitor) of a boost converter seen as a perfect square wave?
Original question:
Why is the output voltage (without capacitor) of a boost converter seen as a perfect square wave?
The output voltage of a boost converter must be across a capacitor, because a ...
- 944
2
votes
Shorted Input Protection
The use of this diode is well explained in the datasheet, but I will try to summarize in my own words:
This diode protects the LTM8053 against reverse current. Reverse current happens when Vin is ...
- 6,536
2
votes
Is it recommended to set the current limit on a bench power supply by shorting it?
The manual for a bench supply can't telepathically know what kinds of leads one is going to have hooked up to it, nor what one will be powering with it. A 5A 20V supply shouldn't be damaged by having ...
- 46.1k
2
votes
How bad of an idea is it to use an AC transformer for a DC-DC converter?
How Bad of An Idea Is It to Use an AC Transformer for a DC-DC Converter?
It is a bad idea.
Are there any problems I haven't already thought of? If so, how easy or difficult are they to solve?
There ...
- 20.3k
2
votes
Accepted
Buck converter inductor ripple current percentage
I decided to check the result on the TI software Webench and I was
surprised to find a much lower inductance value of 2.2µH
That value seems in the right ball-park for the boundary condition: -
Your ...
- 437k
2
votes
Accepted
How Much Cross Sectional Area Should Transformer Core Have Given Current and frequency?
If I know the output current i, output power p, and switching frequency f, how much cross sectional area should the core have?
You have the wrong dimensions, so your thinking appears to be somewhat ...
- 159k
2
votes
Accepted
How can you calculate Peak Pulse Power for a Non-Rectangular Power Pulse
The same document explains this on item 4:
So, you need to write the voltage's equation and solve the energy integral:
$$
E = \int_{T1}^{T2}p(t) \ dt
$$
If you have \$p(t)\$ put it directly. If you ...
- 27.5k
2
votes
Accepted
Push pull for low power application
It's not a forward converter, it's a charge pump. Sort of. That's a bit of an abuse of terminology, but there is no closer, specific term for it.
To be clear, it's not a forward converter, because, ...
- 24.3k
2
votes
What to expect from adjusting the suggested EMI filter and surge protection on a DC/DC power supply's application note. 61000-4-5
Because it is AC powered now I figure I need line to earth surge protection in order to get the same or better ratings for 61000-4-5.
I don't think you can get better immunity as the converter module ...
- 27.5k
1
vote
Accepted
Telling loop instability from ringing
That's all correct, though what constitutes a "small" signal is dependent on the individual system.
Without a thorough analysis you can't know by looking at an oscillation that it's small ...
- 23.1k
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