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> “We shrunk the sensors and got high fidelity signals,” Chung says, “by figuring out novel ways to fit more powerful sensors into tight spaces.” Some of that h

by dom0 9y ago

> “We shrunk the sensors and got high fidelity signals,” Chung says, “by figuring out novel ways to fit more powerful sensors into tight spaces.” Some of that had to do with the arrangement of the magnetic material, he says, but can’t say more until patents are filed. Which is interesting. I guess the main component here is manufacturing cost, since very small, very high capability probes exist since the ~60s. E.g. Tektronix has had small probes with 50-100 MHz [which is orders of magnitude wider than you'd need for this] bandwidth since then.

jerryr 9y ago
It's cost, size, and regulatory. Existing current probes that are magnetically coupled and thus don't require an electrical connection to the mains (which would be a safety/regulatory nightmare) are big: http://www.tek.com/current-probe http://www.tek.com/current-probe
- dom0 9y ago
  A small probe, like the P6021 (which I own [0]) is pretty small. The transformer itself is tiny; there is only a small PCB in the handle with some frequency compensation. (However it is said that these are difficult to manufacture - more so for their Hall-enhanced partners - due to the precisely ground halves of the core). The bigger probes that are meant to go on bare, live bus bars and such are probably mostly air to give the operator the required safe handling distance... probably not an issue for a clip-on probe that goes on insulated wires? [0] Technically a P6021 sold to Philips who bundled it up with a matching amplifier of their own design.
  - jerryr 9y ago
    That probe is pretty small, but keep in mind that many of these need to be tucked into existing circuit breaker panels while maintaining certain clearances for regulatory reasons. They also need to be easy to install for safety and product adoption reasons. I think we are saying similar things though. I worked on this project with Verdigris (though I was not personally responsible for the design of these probes) and, to your original point, the challenge is fitting these at a reasonable cost while achieving the desired accuracy. I guess I'm so used to low manufacturing costs being a given that I tend to focus more on the other aspects of the problem.

by dom0 9y ago

jerryr 9y ago

It's cost, size, and regulatory. Existing current probes that are magnetically coupled and thus don't require an electrical connection to the mains (which would be a safety/regulatory nightmare) are big: http://www.tek.com/current-probe http://www.tek.com/current-probe

dom0 9y ago
A small probe, like the P6021 (which I own [0]) is pretty small. The transformer itself is tiny; there is only a small PCB in the handle with some frequency compensation. (However it is said that these are difficult to manufacture - more so for their Hall-enhanced partners - due to the precisely ground halves of the core). The bigger probes that are meant to go on bare, live bus bars and such are probably mostly air to give the operator the required safe handling distance... probably not an issue for a clip-on probe that goes on insulated wires? [0] Technically a P6021 sold to Philips who bundled it up with a matching amplifier of their own design.
- jerryr 9y ago
  That probe is pretty small, but keep in mind that many of these need to be tucked into existing circuit breaker panels while maintaining certain clearances for regulatory reasons. They also need to be easy to install for safety and product adoption reasons. I think we are saying similar things though. I worked on this project with Verdigris (though I was not personally responsible for the design of these probes) and, to your original point, the challenge is fitting these at a reasonable cost while achieving the desired accuracy. I guess I'm so used to low manufacturing costs being a given that I tend to focus more on the other aspects of the problem.