US1760520A

US1760520A - Temperature-regulating apparatus

Info

Publication number: US1760520A
Application number: US279812A
Authority: US
Inventors: John H Payne
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1928-05-22
Filing date: 1928-05-22
Publication date: 1930-05-27
Anticipated expiration: 1947-05-27

Description

May 27, 1930. J; H. PAYNE 1,760,520

TEMPERATURE REGULATING APPARATUS F1193 May 22, 1928 Inventcr: John HPayna. y

His Attorney Patented May .27, 1930 UNITED STATES,

PATENT OFFICE JOHN H. PAYNE, OF BALLSTON SPA, NEW YORK, ASSIGNOB 'I'O GENEBAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK Application filed May 22,

- sparking at the contacts of a heat responsive element utilized to regulate the heating current of a body which is required to be maintained at a substantially constant temperature. Thus in the manufacture of pie zo electric crystals from a chemical solution, for example,-injurious sparking between the contacts of the heat responsive element is likely to prevent the fine degree of temperature regulation which is required for the proper growth of the crystal. In accordance with my invention, this difliculty is avoided by the provision of an improved temperature regulating apparatus including a space discharge device which has its grid potential controlled in accordance with the temperature of the body to be heated.

My invention will be better understood from the following description when considered in connection with the accompanying drawing and its scope will be pointed out in;

the appended claims.

The drawing diagrammaticallyillustrates a temperature regulating apparatus wherein my invention has been embodied.

This apparatus comprises a heating element 1 located within a vessel 2 and arranged to be connected to a suitable source of heating current through switches 3 and 4 and supplyterminals 5.. The switch 3 is biased to its open position by a spring 6 and is provided with a closing coil 7 which is arranged to be connected to the supply leads 5 through the switch 4, a space discharge device 8 and a pair of resistors 9 and 10. The space dischargedevice 8 includes an anode 11, a cathode 12, and a grid 13 which is connected to the cathode 12 through impedance devices shown as a resistor 14 and resistor 10. The grid potential of the device 8 is controlled 1928. Serial 1T0. 279,812.

by a heat responsive element 15 mounted in the vessel 2 and provided with a solid contact 16 and a liquid contact 17 which assumes a position dependent on the temperature within the vessel 2. 4

Assuming the current supply terminals 5 to have the polarities indicated in the drawing, sufficient current is-transmitted through the device 8 to close the switch 3 only when the

contacts

16 and 17 of the heat responsive element 15 are disengaged from one another.

Thus'when the

contacts

16 and 17 are disengaged from one another the grid 13 is connected to the positive terminal through the resistor 14 and tends to assume a positive potential with respect to the cathode. When the

contacts

16 and 17 are in engagement with one another, however, the resistor 14 is connected between the supply terminals 5 with the grid at the negative terminal and insufficient current to operate the switch 3 is transmitted through the device.

When the grid 13 is connected to the positive supply, terminal through the resistor 14, it is subjected to'a positive bias potential of a magnitude dependent on the potential drop produced in the resistorlO by the cathode heating currents of the device 8. When the grid 13 is connected to the negative supply terminal through the device 15, it is subjected to a negative bias potential dependent on the potential drop produced in the resistor. 9 by the cathode heating current. These bias potentials are of advantage in that they tend to maintain the current of the device 8 at a value which is either slightly above or'below that required to operate the switch 3 so that the switch 3 is very sensitive to change in the relation between the contacts of the heat responsive element 15.

It has been found that the resistance of resistor 14 should be made fairly high in order to prevent sparking at the contactsvof the device 15. The particular value of resistance to be used in each case will of. course depend on the electrical constants of the other-parts of the apparatus. In the practical operation of the apparatus, a resistance of one to ten thousand ohms has been found. satisfactory.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. The combination of a heat producing element, a switch provided with an operating coil and arranged to transmit heating current to said element, a space discharge device provided with a cathode and an anode for transmitting operating current to said cOil and with a grid for controlling said operating current, means in circuit with said cathode providing a positive and a negative biasing potential with respect to said cathode, means including a resistor for applying one of said biasing potentials to said grid, and means including a contact and closure means therefor operable in response to the heat produced by said heating element for applying the other of said biasing potentials to said grid.

2. The combination of a heat producing clement, electrical current supply terminals, a switch provided with an operating coil and arranged to interconnect said element with said terminals, a space discharge device provided with a cathode and anode connected between said terminals through said operating coil and with a grid, an impedance device connected between said grid and one of said terminals, and a circuit control device operated in accordance with the heat of said element and connected between said grid and the other of said terminals.

'3. The combination of a heat producing clement, means for controlling the supply of heating current to said element, a space discharge device arranged to control the energizationof said control means and provided with a grid for controlling the current transmitted between its cathode and anode, terminals for supplying heating current to said cathode, an impedance device connected between said grid and one of said terminals, and a circuit control device arranged to operate in accordance with the heat of said element and connected between said grid and the other of said terminals.

4. The combination of a space discharge device provided with a cathode and an anode and with a grid for controlling the current transmitted between said cathode and anode, a pair of terminals for supplying heating current to said cathode, an impedance device connected between said grid and one or said terminals, and a circuit control device connected between said grid and the other of said terminals.

5. The combination of a space discharge device provided with a cathode and an anode and with a rid for controlling the current transmitted etween said cathode and anode, a pair of terminals for supplying heating current to said cathode, impedance devices each connected between-said cathode and a different one of said terminals, an impedance device connected between said grid and one of said terminals, and means arranged to connect said grid to the other of said terminals. In witness whereof, I have hereunto set my hand this 21st day of May, 1928.

JOHN H. PAYNE.