1. In combination with an electromagnetic grab normally powered from a line-voltage source having a cable with an outer end connected to the grab:
a plurality of high-performance capacitors on the grab, connected in parallel, and forming an emergency power supply;
a relay at the outer end of the cable on the grab, operatively connected to the line-voltage source and to the grab, and switchable between a normal position powering the grab from the line-voltage source and not from the emergency power supply and an emergency position powering the grab from the emergency power supply and not from the line voltage source;
alarm means activatable for generating an alarm signal;
control means connected to the relay and to the alarm means for, on detection of a current or voltage parameter of the line voltage being below a predetermined respective threshold, switching the relay into the emergency position and activating the alarm means;
a transmitter connected to an inner end of the cable for continuously outputting into the cable a high-frequency signal; and
a receiver on the grab at the outer end of the cable connected to the relay for operating the relay when the receiver no longer receives the signal.
2. The combination defined in claim 1 wherein both the transmitter and receiver are normally powered from the line-voltage source but have separate respective power supplies capable of powering the transmitter and receiver for respective predetermined limited time periods.
3. The combination defined in claim 2 wherein the limited time period of the receiver is shorter than that of the transmitter.
4. The combination defined in claim 1, further comprising:
means on the grab for charging the emergency power supply when the relay is in the normal position.
5. The combination according to claim 1, wherein the relay switches the grab from connection to the line-voltage source over to connection with the high-performance capacitors in response to a drop in the line voltage below a specified value.
6. The combination according to claim 5 wherein the alarm means generates an acoustic or visual alarm signal in response to the drop in the line voltage.
7. The combination according to claim 1, further comprising:
a transmitter connected to a line-voltage supply cable, and
a receiver connected to the line-voltage supply cable and to the relay.
8. The combination according to claim 7 wherein the transmitter and receiver transmit and receive frequencies that range between 50 and 150 kHz.
9. The combination according to claim 7 wherein the transmitter and the receiver have respective internal emergency power supplies.
10. A method of operating an electromagnetic grab, the method comprising the steps of:
normally powering the grab from a line-voltage power-supply cable;
connecting a transmitter and a receiver having a relay to the cable;
outputting from the transmitter into the line-voltage supply cable a high-frequency test signal; and
receiving and evaluating the signal with a receiver connected to the cable and operating the relay to connect an emergency power supply to the cable whenever the receiver is not receiving the test signal.
11. The method according to claim 10, further comprising the steps of:
measuring line voltage continuously by a current sensor, and
connecting the emergency power supply by the relay to the grab when the measured current falls below a threshold value.
12. The method according to claim 11, further comprising the step of:
generating an acoustic or visual signal whenever the receiver is not receiving the test signal to be received or whenever the current sensor detects that the amperage has fallen below the defined threshold value.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A plasma reaction method comprising steps of:
(a) installing at least one conductive coil set in a closed space;
(b) filling a reaction fluid into the closed space; and
(c) applying an electric field andor a magnetic field to the conductive coil set to make the conductive coil set and the reaction fluid in the closed space interact on each other to carry out plasma reaction in the closed space.
2. The plasma reaction method as claimed in claim 1, wherein there is only one conductive coil set.
3. The plasma reaction method as claimed in claim 1, wherein there are multiple conductive coil sets.
4. The plasma reaction method as claimed in claim 3, wherein the multiple conductive coil sets are symmetrically arranged.
5. The plasma reaction method as claimed in claim 1, wherein the conductive coil set or at least one of the conductive coil sets has at least one terminal extending out of the closed space.
6. The plasma reaction method as claimed in claim 1, wherein the conductive coil set or at least one of the conductive coil sets has at least one terminal sealedly enclosed in the closed space without contacting an exterior of the closed space.
7. A plasma reaction device comprising:
(a) a closed space; and
(b) at least one conductive coil set installed in the closed space, a reaction fluid being filled in the closed space, an electric field andor a magnetic field being applied to the conductive coil set, whereby the conductive coil and the reaction fluid in the closed space interact on each other to carry out plasma reaction in the closed space.
8. The plasma reaction device as claimed in claim 7, wherein the plasma reaction device comprises only one conductive coil set.
9. The plasma reaction device as claimed in claim 7, wherein the plasma reaction device comprises multiple conductive coil sets.
10. The plasma reaction device as claimed in claim 9, wherein the multiple conductive coil sets are symmetrically arranged.
11. The plasma reaction device as claimed in claim 7, wherein the conductive coil set or at least one of the conductive coil sets has at least one terminal extending out of the closed space.
12. The plasma reaction device as claimed in claim 7, wherein the conductive coil set or at least one of the conductive coil sets has at least one terminal sealedly enclosed in the closed space without contacting an exterior of the closed space.