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Type: Posts; User: KlausST

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1. ## Thread: What's the rpoblem of this MIC circuits?

by KlausST
Replies
10
Views
311

### Closed: Re: What's the rpoblem of this MIC circuits?

Hi,

With "input" I meant the signal in your circuit that is marked "Vin".
And yes it goes to the inverting input of the amp.

Note: In your circuit of post#9 there also is a 10k series...
2. ## Thread: White residue after solder mask develope!!!

by KlausST
Replies
3
Views
91

### Closed: Re: White residue after solder mask develope!!!

Hi,

What exactly do you mean?

Add some marks on the pictures.

Klaus
3. ## Thread: Coaxial cable capacitance

by KlausST
Replies
6
Views
167

### Closed: Re: Coaxial cable capacitance

Hi,

Yes you miss the characteristic impedance.

You just need to drive the 75 Ohms of the cable impedance, that's it. This already includes the cable capacitance.
And it's independent of cable...

by KlausST
Replies
10
Views
311

Hi,

No!

Repeated:

Klaus
5. ## Thread: how to calculate ib of PNP

by KlausST
Replies
4
Views
173

### [SOLVED]Closed: Re: how to calculate ib of PNP

Hi

you missed the brackets:
((5V7-V_in-v_d1)*R2/(R1+R2))/R2
then you may simplify it:
--> ((5V7-V_in-v_d1)*R2/(R1+R2))/R2
--> (5V7-V_in-v_d1)/(R1+R2)
(simple Ohm´s law: I = V / R)
6. ## Thread: Transformers on a PCB

by KlausST
Replies
10
Views
311

### [SOLVED]Closed: Re: Transformers on a PCB

Hi,

We are talking about HF. Thus this still is far away from being a GND plane.
All the traces have the same length as before ... and for HF the width doesn´t play much a role.

Simple...
7. ## Thread: how to calculate ib of PNP

by KlausST
Replies
4
Views
173

### [SOLVED]Closed: Re: how to calculate ib of PNP

Hi,

hard to say without values. I guess 300 uA.

No - joke aside.

do you really want us to go give you a mathematical solution for all cases you can think of?
* DC, what range?
* AC, what...
8. ## Thread: Transformers on a PCB

by KlausST
Replies
10
Views
311

### [SOLVED]Closed: Re: Transformers on a PCB

Hi,

It does not depend on whether your circuit produces HF or not, it depends whether your circuit reacts on HF. And this depends on what exactly U1 is.

In either case: In times of many HF...
9. ## Thread: Soldering Iron recommendations

by KlausST
Replies
7
Views
290

### Closed: Re: Soldering Iron recommendations

Hi,

we have more modern ones like JBC for example, but I can see no benefit against the "old ones".
They claim about longer tip liefetime - but we see the opposite.
And no, we don´t need to...
10. ## Thread: 0-100uA analogue meter (needle) to show 0-10v

by KlausST
Replies
6
Views
154

### Closed: Re: 0-100uA analogue meter (needle) to show 0-10v

Hi,

according ohm´s law. 5V input will give 50uA, this is half of 100uA.
So this should be linear.

Nobody can tell whether your meter works linearely or not. How? You don´t give any...
11. ## Thread: Soldering Iron recommendations

by KlausST
Replies
7
Views
290

### Closed: Re: Soldering Iron recommendations

Hi,

In our company we design multilayer PCB, do prototype soldering, rework, repair, low volume production.
In our whole company we only have soldering stations up to 50W.

Mainly we use...
12. ## Thread: PROCESSOR IS REBOOTING when hotplugging usb console to processor's Board through UART

by KlausST
Replies
4
Views
166

### Closed: Re: PROCESSOR IS REBOOTING when hotplugging usb console to processor's Board through

Hi,

I didn't talk about "onboard" either...

Before you just talked about a laptop and FTDI....but now I have to assume it's not the laptop that is rebooting.
You know ... any laptop has a...
13. ## Thread: PROCESSOR IS REBOOTING when hotplugging usb console to processor's Board through UART

by KlausST
Replies
4
Views
166

### Closed: Re: PROCESSOR IS REBOOTING when hotplugging usb console to processor's Board through

Hi,

You talk about RS232 signal lines.

But I think the signal lines do not cause the problem.
I'm even not sure if it's a hardware problem at all.
It may be a software problem:
* OS, FTDI...
14. ## Thread: [PIC] Car Cooling System PSU Design Related

by KlausST
Replies
24
Views
798

### Closed: Re: [PIC] Car Cooling System PSU Design Related

Hi,

There are still a lot if issues..already discussed.

A new one is Q5.
What does it do? It disconnects GND to U1 in a live system. GND is it's reference...most voltages specified in the...
15. ## Thread: Simple ADC code in XC8 for PIC16F18856

by KlausST
Replies
3
Views
200

### Closed: Re: Simple ADC code in XC8 for PIC16F18856

Hi,

Do the timings really make sense?
* discharging C_Hold typicaly takes a microsecond or so, discharging it for 250us won't do anything..
* sampling time is also in the range of...
16. ## Thread: What's the rpoblem of this MIC circuits?

by KlausST
Replies
10
Views
311

### Closed: Re: What's the rpoblem of this MIC circuits?

Hi,

A2 has a defined gain of -1, thus it should work.

A1 has an input impedance of 1600 Ohms @ 1kHz (C7). This causes a gain of -32 @ 1kHz. But there is a good chance that it oscillates ......
17. ## Thread: What's the rpoblem of this MIC circuits?

by KlausST
Replies
10
Views
311

### Closed: Re: What's the rpoblem of this MIC circuits?

Hi,

I think the circuit could work.

But why do you use a pulse input ... of that high magnitude.?
--> Use a sine shape waveform of 1kHz and 30mV amplitude.

The circuit as is amplifies high...
18. ## Thread: [PIC] Car Cooling System PSU Design Related

by KlausST
Replies
24
Views
798

### Closed: Re: [PIC] Car Cooling System PSU Design Related

Hi,

Why not simply switching low side = GND of the peltier?
Why not using a dedicated Highside_switch?
Why not using standard P_channel circuits to control high side?

Klaus
19. ## Thread: Supercap charging using load switch and current limit resistor

by KlausST
Replies
1
Views
91

### Closed: Re: Supercap charging using load switch and current limit resistor

Hi,

Yes. Turn ON starts at about 1.8V, but one can not see this, becayse the signal is chip internal. But after the turn ON delay you see the output.

As always: (true for any resistive...
20. ## Thread: automated physical keystroker

by KlausST
Replies
2
Views
226

### Closed: Re: automated physical keystroker

Hi,

"keyboard" has many meanings. Please clarify which one you mean.

And describe the expected function.
Example: computer keyboard.
Do you want to press a single key and never any other (to...
21. ## Thread: How to access Micron MT25Q nor flash

by KlausST
Replies
4
Views
323

### Closed: Re: How to access Micron MT25Q nor flash

Hi,

A lot of text, no clear question, not much we can verify...

* (a link to) the datasheet
* the scope picture
* schematic
* register contents (maybe the memory...
22. ## Thread: problem with coding 123

by KlausST
Replies
8
Views
475

### [SOLVED]Closed: Re: problem with coding 123

Hi,

Do you think you find a single person in this forum who does not think reading documents is boring?

There´s no way around.

Klaus
23. ## Thread: Tracking Phase comparator Logic

by KlausST
Replies
12
Views
435

### Closed: Re: Tracking Phase comparator Logic

Hi

Then you don´t need to accumulate something, you just need to measure the phase difference.

If phase difference is 5us --> show 5us (= "1" )
If phase difference is 10us --> show 10us (=...
24. ## Thread: Tracking Phase comparator Logic

by KlausST
Replies
12
Views
435

### Closed: Re: Tracking Phase comparator Logic

Hi,

What about a sketch and/or timing diagram?

"Phase should be accumulated", means:at the beginning, if phase is 5us then the result is "5us" .... if at the next period the phase still is 5us...
25. ## Thread: Tracking Phase comparator Logic

by KlausST
Replies
12
Views
435

### Closed: Re: Tracking Phase comparator Logic

Hi,

I'm still not sure whether you want a digital system or an analog system.

XOR --> low_pass_filter --> analog value
You may use an additional DFF to find lead/lag information.

Or you use...
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