Hello
Customer would like to meet 16000rpm ( 266.6rps). Do you have any suggestion or comments for 12bit or 14 bit resolution that more suitable for this specification? It looks max rps of 12 bit and 14 bit should meet 266.6 rps. Thank you.
Xtal:8.192Mhz
Pole pair: 4
Speed: 16000rpm (266.6rps)
BR
Patrick
Patrick,
Can you comment on if the speed quoted already accounts for the speed multiplier of the pole pair (electrical speed) or if it is the mechanical speed of the monitored shaft? Also is there a requirement…
Your understanding of the electrical rotation multiplier is correct and we would expect that at maximum velocity the resolver would generate a signal equivalent to 32000 RPM or 533 RPS. For this…
If I understand your queries correctly you are asking if velocity, tracking rate, etc. scale linearly with the input clock. The answer is yes that is correct.. If I'm missing anything else let…
Can you comment on if the speed quoted already accounts for the speed multiplier of the pole pair (electrical speed) or if it is the mechanical speed of the monitored shaft? Also is there a requirement for overspeed indication?
Thanks
Sean
Hello Sean
The speed ex 16000rpm should be mechanical speed. Customer's motor is 4 Pole-Pairs. the resolver is 2 Pole-Pairs. So at motor run a cycle, we should get SIN/COS speed become double, is it correct? Please refer to below waveform. above pic is 4 Pole-Pairs, below pic is 2 Pole Pairs.
if correct, the motor run one cycle, the resolver get speed from 16000 rpm to 32000 rpm. If consider resolution setting, we need to depend 32000 rpm for our resolution setting, right?
It is a little urgent, so need your help to clarify above questions, Thank you.
BRPatrick
Your understanding of the electrical rotation multiplier is correct and we would expect that at maximum velocity the resolver would generate a signal equivalent to 32000 RPM or 533 RPS. For this reason I would recommend the customer select 12-bit resolution mode.
Thank you for your suppport. Thanks.
We see our specification most used CLKIN=8.192MHz. Customer request Velocity LSB, tracking rate and other specification depend on CLKIN=10.24 MHz. Do we related specification of 10.24MHz to customer?
BTW, the velocity LSB and tracking rate looks linear to CLKIN. If 12 bit resolution (0.488 rps), it will become to 0.61 rps, right? Thank you.
If I understand your queries correctly you are asking if velocity, tracking rate, etc. scale linearly with the input clock. The answer is yes that is correct.. If I'm missing anything else let me know.
We see many electrical specification on 8.192MHz. Could we know why don't use 10.24MHz CLKIN for electrical specification or by your opinion 10.24MHz CLKIN is more suitable than 8.192MHz CLKIN? Thank you.
Per the specification table
All performance is guaranteed for the entire valid clock range unless otherwise noted. In the specification table where most often we see the specific CLKIN selection noted is to emphasize the linear relationship between the CLK and a specific parameter such as BANDWIDTH or TRACKING RATE.
Per end customer feedback for resolution, there is a little difference by resolution setting as below. It is not recommend 12 bit, 1000rps, CLKIN=8.192MHz for 4x resolver. It is recommend to use 12 bit 1250 rps , CLKIN=10.24MHz. Do you have comment it? Which resolution and CLKIN is correct for 4x resolver (16000 rpm)
Another question, do we have any related doc. to explain motor pole/resolver/RDC relationship and setting for reference? Thank you.
My apologies as I looked back to the original post and I missed that this was a 4x resolver. So yes at 4x with maximum rotational velocity of 16000rpm the AD2S1210 will need to be faster than 1000 rps that is natively available at 8.192MHz. For this reason the customer will need to use a CLKIN = 10.24 MHz.
With regards to the documentation you requested we don't have such a document to my knowledge.
1. Customer's max speed looks 64000RPM. But encoder read speed can not meet 64000 RMP, right? Has any suggestion for encoder ex : has feature to divide max 64000RPM....
2. While measure 160000 RPM via encoder interface, There are different PWM width as below waveform, Is it normal? What is the root cause for this phenomenon?
3. The encoder description looks less on datasheet. What is max RPM support by encoder? It looks has only resolution for setting, right? If any document of encoder description, it will be better. Thank you.
Do you have update for above question? Thank you.