Constant current powered telephone circuits

Claim 2

In a telephone circuit having a two wire telephone connection to a telephone instrument and through a blocking capacitor for each line to other telephone system line wires, a stAbilized current generator circuit supplying constant current when the two-wire telephone line is closed through the telephone instrument comprising, a voltage source having at least two terminals, a positive terminal and a relatively negative terminal; a first multielectrode solid state device having at least an input electrode, a control electrode, and an output electrode with the output electrode connected to a first wire of said two-wire telephone line; the input electrode of said multielectrode solid state device being connected through first resistive means to a first terminal of said voltage source; first voltage divider means connected between the positive terminal and the relatively negative terminal of said voltage source; said voltage divider means having a tap connection with said control electrode of said multi-electrode solid state device; circuit means interconnecting a second wire of said two-wire telephone line and a second terminal of said voltage source; and wherein said first multi-electrode solid state device is a transistor.

Claim 3

The telephone stabilized current generator circuit of claim 1, wherein said first and second multi-electrode solid state devices are transistors; and voltage level responsive circuit means connected to a junction point between the input electrode of said second multi-electrode solid state device and the second resistive means for detecting voltage variations across said second resistive means in detecting telephone ''''off hook'''' and to convert signal pulses originating at said telephone instrument to logic levels used in solid state dial signal pulse registers.

Claim 4

The telephone stabilized current generator circuit of claim 1, wherein said input electrode is an emitter of said transistor, the control electrode is the base of said transistor, and the output electrode is the collector of said transistor; and including a voltage level responsive circuit means connected to a junction point between the input electrode and the first resistive means for detecting voltage variations across said first resistive means.

Claim 5

The telephone stabilized current generator circuit of claim 3, wherein said transistor is a PNP transistor; and said first terminal is the positive terminal of said voltage source.

Claim 6

The telephone stabilized current generator circuit of claim 3, wherein said transistor is a NPN transistor; and said first terminal is the relatively negative terminal of said voltage source.

Claim 7

The telephone stabilized current generator circuit of claim 1, wherein said input electrode is an emitter of said transistor, the control electrode is the base of said transistor, and the output electrode is the collector of said transistor; and with wherein said circuit means is a second resistive means and inculding a voltage level responsive circuit means connected to a junction point between the second wire of said two wire telephone line and the second resistive means for detecting voltage variations across said second resistive means.

Claim 8

The telephone stabilized current generator circuit of claim 6, wherein said transistor is a PNP transistor; and said first terminal is the positive terminal of said voltage source.

Claim 9

The telephone stabilized current generator circuit of claim 6, wherein said transistor is a NPN transistor; and said first terminal is the relatively negative terminal of said voltage source.

Claim 10

In a telephone circuit having a two-wire telephone connection to a telephone instrument and through a blocking capacitor for each line to other telephone system line wires, a stabilized current generator circuit supplying constant current when the two-wire telephone line is closed through the telephone instrument with, a voltage source having at least two terminals, a positive terminal and a relatively negative terminal; a first multi-electrode solid state device having at least an input electrode, a control electrode, and an output electrode with the output electrode connected to a first wire of said twO-wire telephone line; the input electrode of said multi-electrode solid state device being connected through first resistive means to a first terminal of said voltage source; first voltage divider means connected between the positive terminal and the relatively negative terminal of said voltage source; said voltage divider means having a tap connection with said control electrode of said multi-electrode solid state device; a second multi-electrode solid state device having at least an input electrode, a control electrode, and an output electrode with the output electrode connected to said second wire of said two wire telephone line; with said second multi-electrode solid state device interconnecting said second wire of said two wire telephone line and a second terminal of said voltage source, the input electrode of said second multi-electrode solid state device connected through second resistive means to said second terminal of said voltage source; second voltage divider means connected between the positive terminal and the relatively negative terminal of said voltage source; and said second voltage divider means having a tap connection with said control electrode of said second multi-electrode solid state device.

Claim 11

In a telephone circuit having a two-wire telephone connection to a telephone instrument and through a blocking capacitor for each line to other telephone system line wires, a stabilized current generator circuit supplying constant current when the two-wire telephone line is closed through the telephone instrument with, a voltage source having at least two terminals, a positive terminal and a relatively negative terminal; a first multi-electrode solid state device having at least an input electrode, a control electrode, and an output electrode with the output electrode connected to a first wire of said twO-wire telephone line; the input electrode of said multi-electrode solid state device being connected through first resistive means to a first terminal of said voltage source; first voltage divider means connected between the positive terminal and the relatively negative terminal of said voltage source; said voltage divider means having a tap connection with said control electrode of said multi-electrode solid state device; a second multi-electrode solid state device having at least an input electrode, a control electrode, and an output electrode with the output electrode connected to said second wire of said two wire telephone line; with said second multi-electrode solid state device interconnecting said second wire of said two wire telephone line and a second terminal of said voltage source, the input electrode of said second multi-electrode solid state device connected through second resistive means to said second terminal of said voltage source; second voltage divider means connected between the positive terminal and the relatively negative terminal of said voltage source; and said second voltage divider means having a tap connection with said control electrode of said second multi-electrode solid state device.

Claim 12

The telephone stabilized current generator circuit of claim 9, wherein said first resistive means and said second resistive means are of substantially equal value.

Claim 13

The telephone stabilized current generator circuit of claim 9, wherein both of said first and second multi-electrode solid state devices are transistors, one a PNP type transistor and the other an NPN type transistor, with for each transistor said input electrode being the emitter, the control electrode the base, and the output electrode the collector.

Claim 14

The telephone stabilized current generator circuit of claim 11, wherein said first and second resistive means are of substantially equal value.

Claim 15

The telephone stabilized current generator circuit of claim 12, wherein said first and second voltage divider means are of substantially equal ratio with; and the tap connections of said first and second voltage divider means with transistor bases being at substantially the same voltage quantitative value from respective positive and negative terminals of said voltage source.

Claim 16

The telephone stabilizer current generator circuit of claim 13, wherein a connection of said stabilizer current generator circuit is made to a common ground for a telephone system having a plurality of two wire telephone lines and a switching network control center in a system facing high impedance into transistor collectors with balanced two wire telephone lines.