Recent Posts

1

Beginners / Re: 555 driver and Transformer questions

« Last post by DanMann on Today at 07:31:44 pm »

@Andy, I was unsure if high time and low time were the vertical or horizontal stage. By duty cycle I think I now understand.

@Zero999, the transformer is a typical laminated core with one primary winding and one secondary winding, no center tap. It was designed for use with a mechanical vibrator/oscillator that was supposed to operate at 180cps (Hz). Unfortunately these over time have gotten way off with them putting out voltage spikes and frequencies much higher up to 1.2KHz.
I am not understanding push pull, I am guessing single ended.

I am still learning how to use an oscilliscope and do not know all the terms or what what I am seeing actually means, so the following I will do my best of what I think I am seeing.

attached is the schematic (555 oscillator.jpg) of what I am building, sort of. I started with another configuration which would not work with the diodes, but the signal I am getting is showing a duty cycle of 97%. I believe this is due a possible skipped cycle, meaning the signal rises, sharp and quick drop followed by a slightly higher rise.
In changing the time base on the scope the duty and frequency changes, I suspect this is due to the trigger setting?

Attached are pictures. I am not seeing how to put them inline?

2

Beginners / Re: Convert US standard 115V to International 230V

« Last post by am1 on Today at 07:29:12 pm »

Hi all, yes, those are the only PSU used in the device. However, there are several breakers used as well (listed). Many are rated for more than the needed 220-240V, but would I need to replace them with double pole line-neutral breakers? System uses the following:

• Circuit Breaker 2P 20A 240VAC/60DC Blk Rckr      SCHURTER   Allied Electronics   4430.2196
  Circuit Breaker 1-P 4A 480Y/277VAC      ABB   SU201M-C4 
  Circuit Breaker 1-P 2A 480Y/277VAC      ABB   SU201M-C2
  Circuit Breaker 1-P 16A 480Y/277VAC      ABB   SU201M-C16
  Circuit Breaker 1-P 3A 480Y/277VAC      ABB   SU201M-K3
  Circuit Breaker 1-P 15A 480Y/277VAC      ABB   SU201M-K15
  Circuit Breaker 1-P 10A 480Y/277VAC      ABB   SU201M-K10

3

Repair / Re: Low Frequency Continuity Beep for Fluke 8060A

« Last post by Dave Wise on Today at 07:22:27 pm »

I just noticed that attach failed and only the pictures got uploaded.  Here comes schematic, PCB layout, program, and assembly instructions.

I figured out a trick for extending the frequency range on small PIC microcontrollers whose Numerically Controlled Oscillator has an undersize (16 bits) Increment register.  It's in the program comments but I didn't test it as I'd already cut off the programming header.  Affected parts are PIC10F320/2, 12F1501, 16F1503/7/8/9, 16F1713/6/7/8/9.

4

Test Equipment / Using SCPI with python via telnet to connect with a siglent scope

« Last post by eTobey on Today at 07:18:58 pm »

Hi,

i have made a little script to connect to the scope, and read data via SCPI. I have looked at the traffic, and i see, that there is data coming in from the SCPI command (see picture). But it is not printed. But interestingly, the welcome message got printed.

Anyone has an idea?

Code: [Select]

import telnetlib
class POP3Telnet:
    def __init__(self, host, port):
        self.tel = telnetlib.Telnet(host, port)
        #self.lese_daten()
    def close(self):
        self.tel.close()
    def lese_daten(self):
        return self.tel.read_until(b"\n", 1.0)
    def kommando(self, kom):
        self.tel.write(("{}\r\n".format(kom)).encode())
        return self.lese_daten()
       
host = "169.254.143.210"
port = 5024
user = ""
passwd = ""

pop = POP3Telnet(host, port)
#pop.kommando("USER {}".format(user))
#pop.kommando("PASS {}".format(passwd))

#
print("Lese Daten...")
print(pop.lese_daten().decode())
print(pop.lese_daten().decode())
pop.kommando(":MEAS:ADV:P2:STAT? ALL;")
print(pop.lese_daten().decode())
pop.kommando("QUIT")
print(pop.lese_daten().decode())
pop.close()
Output:

Code: [Select]

Lese Daten...
Welcome to the SCPI instrument 'Siglent SDS824X HD'

>>




5

Buy/Sell/Wanted / Re: Fluke 9100 Display....

« Last post by Hamster on Today at 07:18:27 pm »

9500B calibrator (based on the same chassis) seems to be still in production. So you might be able to get a brand new replacement from Fluke...

totally wrong platform.

6

Projects, Designs, and Technical Stuff / Re: Coulomb counter IC for coin cell products.

« Last post by inse on Today at 07:15:47 pm »

Another thing to consider: as the battery is replaceable, how would you know the exact initial capacity?
As different brands could be used or the battery is not factory fresh anymore.
Counting the coulombs would not make sense then..
It all falls back to measuring the cell voltage and making best use of the information.

7

Beginners / Basic PLC Analog Input Question

« Last post by am1 on Today at 07:14:03 pm »

Hi all,

I am using a B&R X20CP0483 system, I am working with a X20AI4222 module (+/-10V) for a simple FSR sensor . I have it wired and working in arduino (see image below for diagram), I have also wired it the same way on my AI mod (A0 is the AI+ pin, and the GND goes to PSU V- and AI-) and have it successfully working. However, since it is a 2 wire device, is there a simpler way to wire this on my PLC (so I can reduce cable wires needed)? DO I need to use the external PSU, or does the module (A+ pin)  simultaneously read the signal with power the device. Do I need a load resistor at all, or could it directly be wired to the module? 

8

Test Equipment / Re: Siglent SDS3000X HD and upgraded SDS1000X HD

« Last post by Martin72 on Today at 07:13:05 pm »

Hi,

I've had the SDS3034X HD for 2 days, but haven't been able to use it yet because I'm too busy at the moment.
However, the competition for this series is no longer to be found at Rigol or other similar manufacturers.
12 bit and 1Ghz....If you look around at Tektronix and Lecroy, you can easily get rid of a lot more money.
At the moment, the only competition to siglent is siglent itself.

9

Test Equipment / Re: Siglent SDS3000X HD and upgraded SDS1000X HD

« Last post by fourfathom on Today at 07:02:05 pm »

I need to upgrade my scope, and the 3000X HD (500MHz or 1GHz) looks very attractive.  I don't want to buy used, and the list price for the 3000X is just around my pain point.  Are there any decent reviews out there?  Would anyone here suggest that I look elsewhere?  I am doing medium speed digital, and RF at 100 MHz and below, and I need to look at signal integrity.  Other analysis tools aren't critical , but you never know what future needs might be.  I've got plenty of other RF tools (SAs, sig gens, etc.)

Any guidance?

10

Test Equipment / Re: Choosing between entry-level 12-bit DSOs

« Last post by ebastler on Today at 06:59:18 pm »

900 switches when all 4 ch on and MSO

I see. Yeah that's kinda expected.
A hacked 800 doesn't do it, it stays on 312.5.

No, it's not really expected. The DHO900 is the only scope I'm aware of which behaves this way.

In typical DSOs, the analog sampling rate is limited by the ADC. (Which is shared across two or four channels, hence sampling rate per channel drops as you activate more analog channels.) But the digital channels are read separately -- they do not need the ADC, and hence don't eat into the ADC bandwidth available for analog sampling.

In contrast, the DHO900 series seems to be limited by the bandwidth of the FPGA/DRAM interface. It uses the same ADC as the larger DHO1000 series, yet runs it at only 1.25 instead of 2 GHz. And when you want to read digital data in parallel, that eats into the available sampling rate.

A hacked DHO800 will behave the same -- as soon as you actually connect and enable a digital probe. Mechatrommer has done that and can comment.