Author Topic: project: extending HP3478A functionality  (Read 12499 times)

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Offline yo0

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Re: project: extending HP3478A functionality
« Reply #125 on: August 12, 2019, 10:13:38 pm »
thank you, now i understand. i was believing was hardware related as i read in fluke 8060a manual.
The fluke 8060a manual says that the base specifications for dB modes are the same as DC Volts/AC Volts.
So I assume it's just a math function.
What are you going to use the dB measurements for?

thank you! audio level adjustments in tape recorders mainly


best regards.

Pio
 

Offline coromonadalix

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Re: project: extending HP3478A functionality
« Reply #126 on: August 13, 2019, 12:22:38 am »
@yoO

You can do your math

0db is 775 mili volts  etc ... you have charts floating on the web ??
 

Offline yo0

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Re: project: extending HP3478A functionality
« Reply #127 on: August 13, 2019, 12:37:07 am »
Thank you, Yes I know, just was a suggestion of features. :)
 

Online Miti

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Re: project: extending HP3478A functionality
« Reply #128 on: August 20, 2019, 12:37:05 am »
great project!, it is possible/viable  add dB measurements, frequency, and remember  the prefered digits  for example 4 1/2? thats will be great!, by the way  there is any source to buy for the project pcbs already populated like drop in solution? @Miti?

best regards.
Pio

Sorry, I missed your question. No, I don't have fully populated boards, only bare boards.
That big spark at power up was by design!
 

Offline yo0

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Re: project: extending HP3478A functionality
« Reply #129 on: August 20, 2019, 02:49:11 am »
great project!, it is possible/viable  add dB measurements, frequency, and remember  the prefered digits  for example 4 1/2? thats will be great!, by the way  there is any source to buy for the project pcbs already populated like drop in solution? @Miti?

best regards.
Pio

Sorry, I missed your question. No, I don't have fully populated boards, only bare boards.

thank you very much, do you think can be a business oportunity for you to sell it like a finished product?  do you think there is enough demand? i think still are thousands 3478a working out there.

if not, do yo have the needed files and the bom to replicate the pcb for sale or share?, i mean for my personal use.

best regards.

Pio
« Last Edit: August 20, 2019, 03:10:06 am by yo0 »
 

Online Miti

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Re: project: extending HP3478A functionality
« Reply #130 on: August 20, 2019, 11:38:16 pm »
thank you very much, do you think can be a business oportunity for you to sell it like a finished product?  do you think there is enough demand? i think still are thousands 3478a working out there.

First of all this is Kirill's project so he should be the one to commercialise it, if he decides to. He must have put much more hours in the SW than I've put in the PCB.
Second, no, I don't see a significant commercial value in this project, designed for a dying multimeter. It is very useful, nice exercise for hobbyists though.
I'm sorry Kirill, I hope you're not offended by what I said.  ;D

Edit: I can sell you a board or two if you want. Contact me on the PM if you want.
« Last Edit: August 20, 2019, 11:39:55 pm by Miti »
That big spark at power up was by design!
 
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Offline yo0

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Re: project: extending HP3478A functionality
« Reply #131 on: August 21, 2019, 12:13:34 am »
thank you very much, do you think can be a business oportunity for you to sell it like a finished product?  do you think there is enough demand? i think still are thousands 3478a working out there.

First of all this is Kirill's project so he should be the one to commercialise it, if he decides to. He must have put much more hours in the SW than I've put in the PCB.
Second, no, I don't see a significant commercial value in this project, designed for a dying multimeter. It is very useful, nice exercise for hobbyists though.
I'm sorry Kirill, I hope you're not offended by what I said.  ;D

Edit: I can sell you a board or two if you want. Contact me on the PM if you want.

Thank for your valuable response, you're right, my apologies.

Best regards.

Pio.
 

Offline kirill_ka

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Re: project: extending HP3478A functionality
« Reply #132 on: August 21, 2019, 12:25:41 pm »
Why apologise? I agree with Miti. I don't think enough items would be sold to justify the effort. Pio, just get the board and build it!
All the parts are easily available and cheap. In fact, I was able to find everything at home. By the way, I highly recommend PC-speaker style buzzer,
as I find variable tone continuity test to be very useful.
 
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Offline kirill_ka

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Re: project: extending HP3478A functionality
« Reply #133 on: August 21, 2019, 12:54:27 pm »
Release 1.4 is ready.
* 5 presets can be saved and loaded. Preset 0 used after power-on (power-on SRQ should be enabled).
* Added menu timeout.
* Fixed key handling in MINMAX mode.
* Added error reporting. If something wrong happened, the error code is displayed.

There's a hidden feature. If an "ext" function used within 5 seconds before entering the menu, that function would be saved in preset.

I didn't have time to test it much as usual (this is the major advantage of non-commercial project by the way  :P).
 
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Online Miti

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Re: project: extending HP3478A functionality
« Reply #134 on: September 11, 2019, 04:02:37 pm »
Hi Kirill,

What compiler do you use?  Can it be compiled with AVR Studo? Can you post the hex and eep as you did before?

Thanks!
That big spark at power up was by design!
 

Offline kirill_ka

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Re: project: extending HP3478A functionality
« Reply #135 on: September 11, 2019, 07:17:11 pm »
Hi Kirill,

What compiler do you use?  Can it be compiled with AVR Studo? Can you post the hex and eep as you did before?

Thanks!

I thought I did upload the binaries  ???
Now it's there.
https://github.com/KIrill-ka/hp3478ext/releases/download/r1.4/hp3478ext-1.4.zip

The compiler is avr-gcc. Windows package is called winavr. And yes,  it comes with AVR Studio.
 
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Online Miti

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Re: project: extending HP3478A functionality
« Reply #136 on: September 12, 2019, 05:21:39 pm »
Kirill,

Most of the externally driven buzzers are single tone, usually the sound intensity decreases significantly outside of the resonant frequency they were designed for. Did you experiment with multiple buzzers, do you have a part number to recommend?
« Last Edit: September 12, 2019, 05:37:17 pm by Miti »
That big spark at power up was by design!
 

Offline kirill_ka

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Re: project: extending HP3478A functionality
« Reply #137 on: September 13, 2019, 07:36:31 pm »
Kirill,

Most of the externally driven buzzers are single tone, usually the sound intensity decreases significantly outside of the resonant frequency they were designed for. Did you experiment with multiple buzzers, do you have a part number to recommend?

I salvaged it from a PC motherboard. The part number is AC-1205G.
The datasheet shows a pronounced resonance @ 2kHz. In practice that AC-1205G sounds ok and I don't feel like it needs a freq response compensation.
https://www.eevblog.com/forum/projects/project-extending-hp3478a-functionality/msg2251509/#msg2251509
 

Offline kirill_ka

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Re: project: extending HP3478A functionality
« Reply #138 on: September 13, 2019, 08:27:40 pm »
Here's the settings I use for now:
Code: [Select]
<GPIB> Ocont_ran
1    # 300 Ohm range
<GPIB> Ocont_beep_ta
5    # 0.5 Ohm resistance for beep_pa & beep_da
<GPIB> Ocont_beep_pa
2000  # 8kHz
<GPIB> Ocont_beep_pb
40000 # 400Hz
<GPIB> Ocont_beep_da
15    # 15/256*100% = ~6% duty cycle
<GPIB> Ocont_beep_db
15
<GPIB> Ocont_beep_tb
1000   # 100 Ohm resistance for beep_pb & beep_db
<GPIB> Ocont_thr
1000   # 100 Ohm threshold where it starts buzzing
<GPIB>
I just noticed a bug in handling cont_thr parameter. There's an integer overflow so it triggers at lower value than specified. I'll publish a fix for it soon.
 

Offline kirill_ka

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Re: project: extending HP3478A functionality
« Reply #139 on: September 20, 2019, 11:46:38 am »
I just noticed a bug in handling cont_thr parameter. There's an integer overflow so it triggers at lower value than specified. I'll publish a fix for it soon.
https://github.com/KIrill-ka/hp3478ext/releases/tag/r1.4.1

I spent some time trying to trace out a rare glitch where wrong data was received from GPIB.
It appeared due to the extension board had a bad contact with the socket. So I soldered contacts from 2mm pitch pin header on the top of the contacts I used previously. Note that I have an older model HP3478A which has a special socket and requires narrow contacts.
 


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