Device driving method, and a device driving apparatus, a signal switching apparatus
A signal switching apparatus comprising multiple relays, multiple photocouplers, wherein an output from the photocouplers is connected to the coils of the multiple relays, and a control device that controls the photocouplers. The coils of the above-mentioned multiple relays are connected so that they are distributed between a positive electrical source and a negative electrical source so that the current flowing to the ground is small.
1 . A method for driving multiple electrical devices which comprises:
supplying current to each of said electrical devices from either a positive electrical source or a negative electrical source connected to a common reference potential, with the positive electrical source and the negative electrical source being divided to said electrical devices and current being supplied to each of said electrical devices such that the difference between the total current supplied from said positive electrical source to said electrical devices and the total current supplied from said negative electrical source to said electrical devices is reduced; and
allowing said current that flows to said electrical devices to be conducted or be interrupted in response to signals from an apparatus that is electrically isolated from said positive electrical source and said negative electrical source.
2 . An electrical device driving apparatus for driving multiple electrical devices, said electric device driving apparatus comprising:
multiple switches which comprise an input part and a switch part that are electrically isolated from one another and said switch part performs a switching operation in response to signals input to said input part; and
each switch part of said switch is connected, with at least one of said electrical devices in between, to either a positive electrical source or a negative electrical source connected so that they are to a common reference potential and said switch part is connected so as to distribute between the positive electrical source and the negative electrical source such that the difference between the total current flowing to said switch part connected to said positive electrical source and the total current flowing to said switch part connected to said negative electrical source is reduced.
3 . The electrical device driving apparatus according to claim 2 , wherein said switch part connected to said positive electrical source and said switch part connected to said negative power source are virtually simultaneously brought to a state of conduction.
4 . A signal switching apparatus that switches between multiple signals, said apparatus comprising:
multiple relays; and
multiple photocouplers;
wherein the output part of each of said photocoupler is connected to the coil of at least one of said relays, and wherein each coil of said relay is connected to a positive electrical source or a negative electrical source having a common ground, with said coils being connected so that they are distributed between the positive electrical source and the negative electrical source such that the difference between the total current flowing to said coils connected to said positive electrical source and the total current flowing to said coils connected to said negative electrical source is reduced.
5 . The signal switching apparatus according to claim 4 , further comprising a control device for controlling each of said photocouplers such that said coils connected to said positive electrical source and said coils connected to said negative electrical source are driven virtually simultaneously.
6 . The signal switching apparatus according to claim 4 , wherein said photocouplers are transistor output photocouplers.
7 . The signal switching apparatus according to claim 4 , wherein said photocouplers are MOS-FET output photocouplers.