C
Chris Carlen
- Jan 1, 1970
- 0
Greetings:
I want to measure the speed of an engine to see how much it slows down
during the compression stroke. It is spun by a dyno, and we suspect the
speed regulation isn't so good when the load gets heavy on compression.
I tried a LM2907 F-to-V converter, but the ripple is too high at the
bandwidth required. I would like the bandwidth to be not much less than
the frequency being measured, so this points toward a digital period
measurement. Ideally it could output the 1/t result on the fly as well,
as an analog signal, but a simple period output would be acceptable.
The device would need to handle frequencies up to 21.6kHz, with minimal
delay from the end of a period to the update of the analog output.
A ready-made instrument would be best, a chip with minimal support
circuitry needed to use it good, and having to make it myself the last
option. I just want to be sure I can't buy this before I go spending
time designing it. If I do have to do it from scratch, it should make a
good CPLD project to exercise my slowly growing logic skills.
Comments appreciated.
Good day!
--
____________________________________
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA
[email protected]
I want to measure the speed of an engine to see how much it slows down
during the compression stroke. It is spun by a dyno, and we suspect the
speed regulation isn't so good when the load gets heavy on compression.
I tried a LM2907 F-to-V converter, but the ripple is too high at the
bandwidth required. I would like the bandwidth to be not much less than
the frequency being measured, so this points toward a digital period
measurement. Ideally it could output the 1/t result on the fly as well,
as an analog signal, but a simple period output would be acceptable.
The device would need to handle frequencies up to 21.6kHz, with minimal
delay from the end of a period to the update of the analog output.
A ready-made instrument would be best, a chip with minimal support
circuitry needed to use it good, and having to make it myself the last
option. I just want to be sure I can't buy this before I go spending
time designing it. If I do have to do it from scratch, it should make a
good CPLD project to exercise my slowly growing logic skills.
Comments appreciated.
Good day!
--
____________________________________
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA
[email protected]