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Type: Posts; User: asdf44

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1. Thread: Shunt in DC ammeter circuit

by asdf44
Replies
7
Views
326

Closed: Re: Shunt in DC ammeter circuit

Unfortunately I don't know that the 'digital panel meter' does exactly.

The marking on it for 30A/60mV indicate it may be configured to scale the signal for your shunt but if that's true you...
2. Thread: Class D amplifier simulation

by asdf44
Replies
8
Views
433

Closed: Re: Class D amplifier simulation

Common to simulate with an individual source for each gate drive. Unlike real life there is no penalty for fully isolated gate drive in the simulated. Connect the gate drive source across Vgs.
3. Thread: Shunt in DC ammeter circuit

by asdf44
Replies
7
Views
326

Closed: Re: Shunt in DC ammeter circuit

I assume you mean 30A->60mV not mA. Shunts convert current to voltage.

Use a volt-meter to measure the shunt.
4. Thread: SMPS feedback compensation..origin pole is "pole at origin"?

by asdf44
Replies
3
Views
315

Closed: Re: SMPS feedback compensation..origin pole is "pole at origin"?

I guess I'm not clear on the definitions here either.

When I design Type II compensators think in terms of the frequency at which the left-most pole slope would cross -3db if there was nothing...
5. Thread: Type one compensator...why is everybody giving it a phase of -90 degreees

by asdf44
Replies
2
Views
194

Closed: Re: Type one compensator...why is everybody giving it a phase of -90 degreees

Type I is just a single pole integrator. Poles are understood to introduce a 90 degree phase lag or -90 degree phase shift.

Other phase shifts can be seen as external.

by asdf44
Replies
7
Views
549

Closed: Re: LTSpice Noise Analyis

On a sort of related note does anyone have an understanding of why instrumentation amplifiers have such high noise?

For example AD8429 billed as 'ultralow noise' has 45 nV/√Hz output noise. So 45...
7. Thread: Working of TL431 Optocoupler feedback design circuit

by asdf44
Replies
2
Views
271

Closed: Re: Working of TL431 Optocoupler feedback design circuit

It’s an integrating cap used to compensate the feedback loop.

It limits the bandwidth (or response time) of the feedback loop to prevent oscillations.
8. Thread: Is this a good Oscilloscope

by asdf44
Replies
3
Views
312

Closed: Re: Is this a good Oscilloscope

It might be fine but Siglent is the best low end scope right now in my opinion. 1104x-e.
9. Thread: Lattice FPGAs and Diamond software

by asdf44
Replies
5
Views
571

Closed: Re: Lattice FPGAs and Diamond software

I've used Lattice (on and off for 15 years or so), Xilinx (A lot in the last 10 years or so) and Altera (one project recently).

In terms of tool quality the ranking is pretty clear:
1) Xilinx...

by asdf44
Replies
7
Views
549

Closed: Re: LTSpice Noise Analyis

Wait I have to take my last statement back. I simply screwed up the importing of the OPA140 model (symbol was still referencing an ideal model). So on a second quick look the OPA140 and a handful...

by asdf44
Replies
7
Views
549

Closed: Re: LTSpice Noise Analyis

Ok and part of my question is about realistic model expectations.

For example TI's OPA140 has no noise when simulated in LTSpice's noise mode.

Of course this is what I expected - performance...
12. Thread: Optimally Accurate 28-bit A/D conversion

by asdf44
Replies
8
Views
449

Closed: Re: Optimally Accurate 28-bit A/D conversion

Agree except I'd point out that the way this is handled is with ranging.

It is possible to make a system with 180nV resolution that can also handle 3V full scale....just not at the same time.
13. Thread: How to use the same RELAY on 12V & 24V vehicles

by asdf44
Replies
10
Views
599

Closed: Re: How to use the same RELAY on 12V & 24V vehicles

Agree with the regulator suggestion. 12V regulator or 9V regulator. If 12V is fed to a 12V regulator it should just saturate at its dropout voltage (~11.5V for example) and will work fine.

...
14. Thread: How to "de-resonate" a resonant circuit?

by asdf44
Replies
5
Views
396

Closed: Re: How to "de-resonate" a resonant circuit?

Clamp the inductor with a diode.

Replace the resistor with a current source.

Choose an inductor that saturates at low currents to limit resonant energy storage.

Though you’re not clear...
15. Thread: PSIM Problem in a Basic Circuit (Unable to load psim.dll)

by asdf44
Replies
1
Views
291

Closed: Re: PSIM Problem in a Basic Circuit (Unable to load psim.dll)

I’ve used pain a lot and have never seen it.

Restart, reinstall, contact tech support.
16. Thread: How to instantiate a submodule in Verilog

by asdf44
Replies
36
Views
1,464

Closed: Re: How to instantiate a submodule in Verilog

Yes its common thus worth me saying “It doesn’t have to be that way”.

The software world has the same debate about classes and I think the right answer is the same: it makes sense sometimes.
...
17. Thread: How to instantiate a submodule in Verilog

by asdf44
Replies
36
Views
1,464

Closed: Re: How to instantiate a submodule in Verilog

Don't agree.

I often find it preferable to leave multiple associated modules in a single file including the test-bench for that module.

And it certainly isn't the cause of the problems here.

by asdf44
Replies
7
Views
549

Closed: LTSpice Noise Analyis

Does anyone understand how LTSpice's noise simulation works under the hood?

I've used LTSpice extensively but barely touched the noise mode (I'm trying to catch up on my understanding of noise...
19. Thread: input current of the integrator

by asdf44
Replies
15
Views
928

Closed: Re: input current of the integrator

Yep that's exactly it.
20. Thread: input current of the integrator

by asdf44
Replies
15
Views
928

Closed: Re: input current of the integrator

Because keeping the + and - inputs equal (by sourcing or sinking output current/voltage) is the textbook behavior of an opamp.

Though it has limits in its ability to do that (output current,...

by asdf44
Replies
10
Views
715

Closed: Re: overvoltage protection

If you need <5% variation in clamping voltage no 2 terminal off the shelf device is going to do it.

They’re not a bad idea, and may be what you want, but understand they don’t have that kind of...

by asdf44
Replies
4
Views
499

Closed: Re: 24Vdc Relay for a DC load of 2A 600V

Low amp DC is a good candidate for solid state solutions, here is an example of something close:

This depletion fet is normally on. 2 in series back-to-back for AC blocking with a...
23. Thread: input current of the integrator

by asdf44
Replies
15
Views
928

Closed: Re: input current of the integrator

Understand that AC current is DC current until it switches direction. 50hz AC is DC for 10ms periods.

So a cap is perfectly happy passing DC current...until its voltage as described by the...
24. Thread: Use an OR wired with diodes to control the gate in a PMOSFET

by asdf44
Replies
28
Views
1,296

Closed: Re: Use an OR wired with diodes to control the gate in a PMOSFET

You have some problems.

The diodes prevent the NPN's from ever turning on the gate.

Second you need a wired nand it seems:
If all inputs are 0 -> good -> pull down gate -> turn on pfet
If any...
25. Thread: Circuit to pulse from 1v to 1.1v repeatedly.

by asdf44
Replies
8
Views
579

Closed: Re: Circuit to pulse from 1v to 1.1v repeatedly.

Agree: just switch or mux the opamp reference.

A second option is to mux two different sources. NLASB3157 is an example of SPDT analog mux.
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