Hi Bud,
not sure about the regulations here. If needed, I can delete the post in testgear.
Hi tggzzz,
Thanks for the questions!
The answer to the 1st one: Yes, different models have different configuration of registers and relays.
The 2nd one: QR10 uses a more elegant and accurate way to handle the "residual resistance" than traditional Resistance Decade Box. This is also one of the advantages of QR10.
QR10 has an MCU to control the relay coil of "Relay-Resistor Network". When user set 10 Ω, and we already know (measured) the relay contact resistance and the PCB routing resistance is, say 0.5 Ω. Then we offset this 0.5 Ω in advance and set the switch to produce 9.5 Ω.
It is an interesting take on a programmable resistor, but I do not like the serial protocol.
It may work fine for control from a terminal, but for control from a program I would prefer it more simple and SCPI like. I would probably be possible to have a extra command set for that.
Something like:
Set resistance value, will not return any answer: set xxx
Asked current resistance value, will return one number with a CR LF termination: set?
And maybe a few more command to read the other values, but no multi line return values. Multiple values can be return as "value1 value2 value3 CR LF", i.e. with spaces between and no text.
That allows a zero differential resistance under some conditions, but you claim a zero residual resistance.
Presume you have entered the offset values, and selected 0ohms. To use hypothetical numbers, if there is 0.01ohms resistance in the wires and 0.01ohms resistance in each of 9 relays, then the resistance between the terminals would be 0.1ohms, not the 0ohms you claim. Hence the residual resistance would be 0.1ohms, not 0ohms.
Hi tggzzz,
Thanks for the questions!
The answer to the 1st one: Yes, different models have different configuration of registers and relays.
The 2nd one: QR10 uses a more elegant and accurate way to handle the "residual resistance" than traditional Resistance Decade Box. This is also one of the advantages of QR10.
QR10 has an MCU to control the relay coil of "Relay-Resistor Network". When user set 10 Ω, and we already know (measured) the relay contact resistance and the PCB routing resistance is, say 0.5 Ω. Then we offset this 0.5 Ω in advance and set the switch to produce 9.5 Ω.
That allows a zero differential resistance under some conditions, but you claim a zero residual resistance.
Presume you have entered the offset values, and selected 0ohms. To use hypothetical numbers, if there is 0.01ohms resistance in the wires and 0.01ohms resistance in each of 9 relays, then the resistance between the terminals would be 0.1ohms, not the 0ohms you claim. Hence the residual resistance would be 0.1ohms, not 0ohms.
What is the specification for the relay contact changes over time, e.g. after 10000 operations, and with relay orientation?
What is the specification for the relay contact changes with changing relay orientation?
That will determine how the well calibrated your device remains.
If you are producing something aimed at hobbyists, then your device may well be sufficient. But you are comparing it with high quality standard resistors, and your comparisons appear invalid and statements incorrect. I am willing to be convinced otherwise.
Hi tggzzz,
Thanks for the questions!
The answer to the 1st one: Yes, different models have different configuration of registers and relays.
The 2nd one: QR10 uses a more elegant and accurate way to handle the "residual resistance" than traditional Resistance Decade Box. This is also one of the advantages of QR10.
QR10 has an MCU to control the relay coil of "Relay-Resistor Network". When user set 10 Ω, and we already know (measured) the relay contact resistance and the PCB routing resistance is, say 0.5 Ω. Then we offset this 0.5 Ω in advance and set the switch to produce 9.5 Ω.
That allows a zero differential resistance under some conditions, but you claim a zero residual resistance.
Presume you have entered the offset values, and selected 0ohms. To use hypothetical numbers, if there is 0.01ohms resistance in the wires and 0.01ohms resistance in each of 9 relays, then the resistance between the terminals would be 0.1ohms, not the 0ohms you claim. Hence the residual resistance would be 0.1ohms, not 0ohms.
What is the specification for the relay contact changes over time, e.g. after 10000 operations, and with relay orientation?
What is the specification for the relay contact changes with changing relay orientation?
That will determine how the well calibrated your device remains.
If you are producing something aimed at hobbyists, then your device may well be sufficient. But you are comparing it with high quality standard resistors, and your comparisons appear invalid and statements incorrect. I am willing to be convinced otherwise.
Hi tggzzz,
I'm CC, Frank's colleague. Since he is in bed right now, allow me to answer your question.
1. The concept of “residual resistance” you mentioned is actually from the old fashined resistance box for that it can do nothing about cable resistance and switch contact resistance. While for QR10, we can re-define residual resistance as “0”
for the reason it was already included in the output PV (we measured it in advance and based on it to decide “Relay-resistor” combination value).
2. For relay performance, we did a lot test in our EVT 125 units and found it's much stable than the specification given. If you want to see the original data, just send us an email to eastwood.tech@outlook.com
3. The relay we choosed is not liquid type. No such limitation in orientation.
4. QR10 is for hobbyists, but it doesn't mean low quality and shit. And it's for general purpose application rather than "resistance standard" - we will charge you 10 times more if it is.
Thanks for your question, appreciate it indeed!
Hi tggzzz,
Thanks for the questions!
The answer to the 1st one: Yes, different models have different configuration of registers and relays.
The 2nd one: QR10 uses a more elegant and accurate way to handle the "residual resistance" than traditional Resistance Decade Box. This is also one of the advantages of QR10.
QR10 has an MCU to control the relay coil of "Relay-Resistor Network". When user set 10 Ω, and we already know (measured) the relay contact resistance and the PCB routing resistance is, say 0.5 Ω. Then we offset this 0.5 Ω in advance and set the switch to produce 9.5 Ω.
That allows a zero differential resistance under some conditions, but you claim a zero residual resistance.
Presume you have entered the offset values, and selected 0ohms. To use hypothetical numbers, if there is 0.01ohms resistance in the wires and 0.01ohms resistance in each of 9 relays, then the resistance between the terminals would be 0.1ohms, not the 0ohms you claim. Hence the residual resistance would be 0.1ohms, not 0ohms.
What is the specification for the relay contact changes over time, e.g. after 10000 operations, and with relay orientation?
What is the specification for the relay contact changes with changing relay orientation?
That will determine how the well calibrated your device remains.
If you are producing something aimed at hobbyists, then your device may well be sufficient. But you are comparing it with high quality standard resistors, and your comparisons appear invalid and statements incorrect. I am willing to be convinced otherwise.
Hi tggzzz,
I'm CC, Frank's colleague. Since he is in bed right now, allow me to answer your question.
1. The concept of “residual resistance” you mentioned is actually from the old fashined resistance box for that it can do nothing about cable resistance and switch contact resistance. While for QR10, we can re-define residual resistance as “0”
Nonsense: you can't simply re-define a standard techincal term to suit your marketing.
Or, if you can, then the concept of "web forum" is from the old-fashioned web 1.0, and I can redefine EEVBlog Forum as a "usenet forum".
Or perhaps I can define that a car "floats" on water, because with the doors shut it takes quite a few seconds before the water is up to the windows.
Any and all of those redefinitions are crap designed to confuse and hide.
If a user can't select 0ohms, put a current through your device and measure zero volts across the terminals, then the residual resistance isn't zero ohms.
Simply state the minimum resistance between the terminals, and state the increments you can set on top of that minimum resistance. Anything else is deliberately deceptive.Quotefor the reason it was already included in the output PV (we measured it in advance and based on it to decide “Relay-resistor” combination value).
What is "PV" or "process value"?
I guess it means incremental resistance. But nobody cares what my guess is.
Please stop creating datasheets using cheese[1]
[1] my definition of cheese is a computer program that enables creation of written documents! Stupid? No more than your inventing terms!
Quote2. For relay performance, we did a lot test in our EVT 125 units and found it's much stable than the specification given. If you want to see the original data, just send us an email to eastwood.tech@outlook.com
Nobody cares about your measurements; they could be flukes or badly implemented.
The next batch of relays might be very different. The same batch might have a very different measurement next week. And nobody could complain.Quote3. The relay we choosed is not liquid type. No such limitation in orientation.
Is that guaranteed by the specification or by you not finding any issue yesterday?Quote4. QR10 is for hobbyists, but it doesn't mean low quality and shit. And it's for general purpose application rather than "resistance standard" - we will charge you 10 times more if it is.
Thanks for your question, appreciate it indeed!
Nothing wrong with it being general purpose, but don't compare it to standard resistors.
I wouldn't compare a Toyota Yaris to a Rolls Royce.
Hi tggzzz,
Thanks for the questions!
The answer to the 1st one: Yes, different models have different configuration of registers and relays.
The 2nd one: QR10 uses a more elegant and accurate way to handle the "residual resistance" than traditional Resistance Decade Box. This is also one of the advantages of QR10.
QR10 has an MCU to control the relay coil of "Relay-Resistor Network". When user set 10 Ω, and we already know (measured) the relay contact resistance and the PCB routing resistance is, say 0.5 Ω. Then we offset this 0.5 Ω in advance and set the switch to produce 9.5 Ω.
That allows a zero differential resistance under some conditions, but you claim a zero residual resistance.
Presume you have entered the offset values, and selected 0ohms. To use hypothetical numbers, if there is 0.01ohms resistance in the wires and 0.01ohms resistance in each of 9 relays, then the resistance between the terminals would be 0.1ohms, not the 0ohms you claim. Hence the residual resistance would be 0.1ohms, not 0ohms.
What is the specification for the relay contact changes over time, e.g. after 10000 operations, and with relay orientation?
What is the specification for the relay contact changes with changing relay orientation?
That will determine how the well calibrated your device remains.
If you are producing something aimed at hobbyists, then your device may well be sufficient. But you are comparing it with high quality standard resistors, and your comparisons appear invalid and statements incorrect. I am willing to be convinced otherwise.
Hi tggzzz,
I'm CC, Frank's colleague. Since he is in bed right now, allow me to answer your question.
1. The concept of “residual resistance” you mentioned is actually from the old fashined resistance box for that it can do nothing about cable resistance and switch contact resistance. While for QR10, we can re-define residual resistance as “0”
Nonsense: you can't simply re-define a standard techincal term to suit your marketing.
Or, if you can, then the concept of "web forum" is from the old-fashioned web 1.0, and I can redefine EEVBlog Forum as a "usenet forum".
Or perhaps I can define that a car "floats" on water, because with the doors shut it takes quite a few seconds before the water is up to the windows.
Any and all of those redefinitions are crap designed to confuse and hide.
If a user can't select 0ohms, put a current through your device and measure zero volts across the terminals, then the residual resistance isn't zero ohms.
Simply state the minimum resistance between the terminals, and state the increments you can set on top of that minimum resistance. Anything else is deliberately deceptive.Quotefor the reason it was already included in the output PV (we measured it in advance and based on it to decide “Relay-resistor” combination value).
What is "PV" or "process value"?
I guess it means incremental resistance. But nobody cares what my guess is.
Please stop creating datasheets using cheese[1]
[1] my definition of cheese is a computer program that enables creation of written documents! Stupid? No more than your inventing terms!
Quote2. For relay performance, we did a lot test in our EVT 125 units and found it's much stable than the specification given. If you want to see the original data, just send us an email to eastwood.tech@outlook.com
Nobody cares about your measurements; they could be flukes or badly implemented.
The next batch of relays might be very different. The same batch might have a very different measurement next week. And nobody could complain.Quote3. The relay we choosed is not liquid type. No such limitation in orientation.
Is that guaranteed by the specification or by you not finding any issue yesterday?Quote4. QR10 is for hobbyists, but it doesn't mean low quality and shit. And it's for general purpose application rather than "resistance standard" - we will charge you 10 times more if it is.
Thanks for your question, appreciate it indeed!
Nothing wrong with it being general purpose, but don't compare it to standard resistors.
I wouldn't compare a Toyota Yaris to a Rolls Royce.
Hi tggzz,
I'm afraid you wend too, FAR. Return and talk in peace, please.
1. Timing and tide is changing and you must accept it. Science and technique is not Bible that can not be modified (for Bibile, who knows:-).
If you don't agree with me, I guess IET Labs can answer your same question about “residual resistance” (here is the link: https://www.ietlabs.com/os-260-resistance-decade-box-rtd-simulator.html). Great minds think alike - I mean, us - Eastwood Instruments and IET labs.
2. If you want to know the relay model, the best way is to order one (or you can apply for a free sample on our official website), tear it down and see. What I can tell you is, the relay brand we selected is from JP. I seldom question our friendly neighbor's quality control. But sure, you can.
3. We all born equal (@admin, this is not talking about politics, please), and the remarkable thing of instruments field is, there is an objective "standard" and even the tiny one can be a gaint.
Why not order one and see? I'll give you a big bargain since we almost be friends already.
Best,
CC
[Humpty Dumpty:] 'And only ONE for birthday presents, you know. There's glory for you!'
'I don't know what you mean by "glory,"' Alice said.
Humpty Dumpty smiled contemptuously. 'Of course you don't--till I tell you. I meant "there's a nice knock-down argument for you!"'
'But "glory" doesn't mean "a nice knock-down argument,"' Alice objected.
'When _I_ use a word,' Humpty Dumpty said in rather a scornful tone, 'it means just what I choose it to mean--neither more nor less.'
'The question is,' said Alice, 'whether you CAN make words mean so many different things.'
'The question is,' said Humpty Dumpty, 'which is to be master--that's all.'
Your comments and professional opinions are highly appreciated!