US3252279A

US3252279A - Device for contactless shaping of electric pulses

Info

Publication number: US3252279A
Application number: US350840A
Authority: US
Inventors: Fedotov Vladimir Nickolaevich; Reifman Mark Petrovich
Original assignee: LENINGRADSKY ZAVOD ELEXTRICHESKIKH CHASOV
Current assignee: LENINGRADSKY ZAVOD ELEXTRICHESKIKH CHASOV
Priority date: 1964-03-10
Filing date: 1964-03-10
Publication date: 1966-05-24
Anticipated expiration: 1983-05-24

Description

DEVICE FOR CONTACTLESS SHAPING OF ELECTRIC PULSES Filed March 10, 1964 United States Patent 3,252,279 DEVICE FOR CONTACTLESS SHAPING OF ELECTRIC PULSES Vladimir Nickolaevich Fedotov and Mark Petrovich Reifman, both of Leningrad, U.S.S.R., assignors to Leningradsky Zavod Elextricheskikh Chasov, Leningrad, U.S.S.R.

Filed Mar. 10, 1964, Ser. No. 350,840

3 Claims. (CI. 58-33) This invention relates to systems for shaping electric pulses of alternate polarity in control circuits of actuating mechanism, mainly in those of electric clocks.

In the existing designs of primary electric clocks contact groups are used to transmit electric pulses frequently to an associated control circuit.

This heavy duty mode of contact group operation results in rapid oxidation of the contact working surfaces which degrades the efficiency and reliability of the clock.

Different devices have been proposed to quench sparks produced in the process of contact operation, but they have not provided the reliability and long life required for contact groups.

An object of the present invention is to eliminate the above-mentioned drawbacks.

To achieve this object, there is proposed a contactless pulse shaping device with a high reliability and long life, said device constitutes the basis of the invention.

More particularly in accordance with the proposal for contactless shaping of alternate polarity pulses in a primary electric clock to be transmitted at one minute intervals to a line of secondary clocks and to the power supply for the electromagnet of the clock mechanism, a drive and a relay are connected, said relay being used only to prepare an actuating device circuit for operation, while pulses are shaped by a transistor connected to the relay circuit and controlled through contacts coupled with cams and a segment which are mounted on the driving axle of the clock mechanism.

The following is a description of one embodiment of the invention. v

The sole figure of the accompanying drawing shows the electrical diagram of a contactless pulse shaping device as applied to a primary clock mechanism with a pendulum drive.

D.C. source 1 (battery) producing a voltage of about 24 v. energizes a circuit comprising relay winding 2 and electromagnet 3 of a pendulum drive (not shown) ger manium diodes 4 are used to extinguish the extra currents caused by the closing and opening of electric contacts provided in the circuits of electromagnet 3 and relay 2.

The circuit of relay 2 contains a triode transistor 5 which shapes electric current pulses whose polarity is inverted with the changeover of

relay contacts

6, 7, 8, 9, 10, and 11 which close loop 12, 13 of the secondary clock through transistors 5 and power supply 1.

The time interval between the electric pulses transmitted to loop 12, 13 of the secondary clock is adjusted by means of two cams 14 mounted opposite to each other on. the rim of a disc 16, which is fixed on the driving axle of the primary clock mechanism.

The rotation of said. disc 16 causes cams 14 together with the first contact 17 to connect the electric circuit of power supply 1 with the base of transistor 5.

Relay 2 is controlled by segment 18 on disc 15 which is mounted coaxially with disc 16 on said axle. While rotating, the segment closes the second contact 19 thus connecting the winding of relay 2 with power supply 1.

Connected to the circuit of the first contact 17 is a resistor 20 which is used to. limit the base current of transistor 5.

3,252,279 Patented May 24-, 1966 Germanium diode 21 shunting the emitter-collector circuit of transistor 5 performs a blocking function and protects transistor 5 against breakdown in case of casual changes of the polarity of power supply 1.

Electrolytic capacitor 22 in the emitter-base circuit of transistor 5 is used to provide a smooth increase or decrease of current in the secondary electric clock loop thus eliminating surge currents which can otherwise appear in it due to the closing and opening of the contacts and which cause radio-frequency interference.

The circuit of electromagnet 3 contains a contact 23 coupled mechanically to the pendulum driveof the primary electric clock. When the contact is closed the winding of electromagnet 3 is connected to power supply 1.

The operation of the device is as follows.

At the start, when contacts 17 and 19 are open, current from power supply 1 will not flow through the loop 12, 13 of the electric clock, since transistor 5 is cut-off.

The rotation of the driving axle makes one of cams 14 of disc 16 close the first contact 17, the second contact 19 remaining open. In this case, the base of transistor. 5 has applied thereto a negative voltage coming from the positive terminal of power supply 1 through limiting resistor 20.

The current from power supply 1 flows through the emitter-collector junction of transistor 5 and the contact pair 8, 10 of relay 2 to the loop of the secondary electric clock and thence it flows back through the

contact pair

11, 9 of relay 2 and fuse 24 to the minus terminal of power supply 1.

As the driving axle continues rotating, segment 18 closes the second contact 19 before the second cam 14 reaches the first contact 17.

In this case, relay 2 operates and switches over the circuit. The secondary clock loop receives no pulse because contact 17 remains open. The circuit is being prepared to shape a pulse of the opposite polarity.

The next moment brings the second cam 14 to close the first contact 17 while the second contact 19 remains closed since segment 18 is considerably wider than cam 14.

With the closing of contacts 17.and 19, the secondary clock loop will receive a pulse travelling in a direction opposite to that of the previous pulse.

The current from power supply 1 flows through the emitter-collector junction of transistor 5 and the

contact pair

7, 11 of relay 2 to the secondary clock loop and thence it flows back through the

contact pair

10, 6 and fuse 24 to the minus terminal of DC. power supply 1.

Therefore, the cams 14 cooperate with the contact 17, and the segment 18 cooperates with the contact 19 during the rotation of

discs

15, 16 mounted on the axle of the clock mechanism in the following manner.-

When disc 16 turns to allow cam 14 to close contact 17, the base of transistor 5 will be supplied with negative bias which opens the transistor. The power source supplies current to the loop 12, 13 of the electric clock via normally closed

relay contacts

8 and 10, 11 and 9.

As disc 16 rotates further, cam 14 clears contact 17 to cause it to open. The voltage across the transistor base will smoothly decrease in the course of discharge of capacitor 22.

The commutator current of the transistor will also smoothly decrease, and as a result the current decreases in the loop 12,.13 so slowly that the energy stored in the in ductive load does not lead to the appearance of disconnecting extra currents, which present danger to both the contacts and the line.

When discs 16 have turned through an angle just short 0 of segment 18 is the first to engage contact 19 and with no current yet flowing in the loop, i.e. the relay contacts have prepared the reversal of current direction.

In the next instant, cam 14 engages contacts 17, and when the latter closes, transistor 5 opens and admits current into the loop, said current being opposite relative to the load.

When cam 14 opens contact 17, segment 18 still engages contact 19 to prevent its disconnection.

Current discontinues in the line, and subsequently segment 18 opens contact 19. Relay contacts and 11 return to the original position.

The cycle is then repeated.

The combination of two cams 14 and segment 18 mounted coaxially on driving axle 16 of the clock mechanism and made to operate in conjunction with electric contacts 17 and 19 which connect the power supply either to the base of transistor 5 or to relay 2 makes it possible to switch over

relay contacts

6, 7, 8 and 9 at the moments when there is no current flowing through the contacts, i.e. to obtain the contactless shaping of pulses of alternate polarity to be tranmitted to the loop of secondary electric clocks and instruments.

The present invention can be widely used for the con tactless shaping of pulses of alternate polarity in pendulum or balance primary electric clocks in which pulses are transmitted at one minute or one second intervals.

What we claim is:

1. A device for contactless shaping of pulses of alternate polarity in a primary electric clock comprising a power source, a semiconductor triode adapted to shape pulses of a definite polarity in response to negative voltage supplied regularly to the base theerof from the power source; a circuit coupling the power source and the triode, switching means connected in the circuit of said semiconductor triode and said power source and adapted to prepare transmission of forward or back current to a secondary clock circuit; and commutator means controlling the switching of said switching means and the transmission of negative voltage to the base of said triode so that the switching means is switched over before negative voltage is supplied to the triode base and is returned to the original position after negative voltage has been fed to the triode base.

2. A device for contactless shaping of pulses of alternate polarity in a primary electric clock comprising a power source, a semiconductor triode adapted to shape pulses of a definite polarity in response to negative voltage supplied regularly to the base thereof from the power source; a capacitor between the base and emitter of said Semiconductor triode to insure smooth decrease of current in the course of pulse shaping; an electromagnetic relay provided with switching contacts connected in the trolling the operation of said electromagnetic relay and the transmission of negative voltage to the base of said triode so that the contacts are switched over before negative voltage is supplied to the triode base and are returned to the original position after negative voltage has been fed to the triode base.

3. A device for contactless shaping of pulses of alternate polarity in a primary electric clock including a clock mechanism with a driving axle, said device comprising a power source, a semiconductor triode adapted to shape pulses of a definite polarity in response to negative voltage supplied regularly to the base thereof from the power source; switching contacts connected in the circuit of said semiconductor triode and said power source and adapted to prepare transmission of forward or back current to the secondary clock circuit, one of said contacts being adapted to supply negative voltage from said power source to the base of said triode; a capacitor between the base and emitter of said semiconductor triode to insure smooth decrease of current in the course of pulse shaping; a commutator including two discs mounted on the driving axle of the clock mechanism, one of said discs including two cams spacedly arranged thereon to engage the contact which supplies negative voltageto the base of said triode, the other disc including a segment serving to switch over the contacts adapted to prepare the transmission of for ward or back current to the secondary clock circuit, said segment being adapted to switchover said contacts before negative voltage is supplied to the triode base and to return the same to the original position after negative voltage has been fed to the triode base. 7

References Cited by the Examiner UNITED STATES PATENTS 2,627,056 1/1953 Gleason 318-27 OTHER REFERENCES 129,545 (certificate of invention-2 pp), May 1958, U.S.S.R. (Chirkin).

LOUIS J. CAPOZI, Primary Examiner. LEO SMILOW, Examiner.

GERALD F. BAKER, Assistant Examiner.

Claims

1. A DEVICE FOR CONTACTLESS SHAPING OF PULSES OF ALTERNATE POLARITY IN A PRIMARY ELECTRIC CLOCK COMPRISING A POWER SOURCE, A SEMICONDUCOR TRIODE ADAPTED TO SHAPE PULSES OF DEFINEITE POLARITY IN REPSONSE TO NEGATIVE VOLTAGE SUPPLIED REGULARLY TO THE BASE THEREOF FROM THE POWER, SOURCE; A CIRCUIT COUPLING THE POWER SOURCE AND THE TRIODE, SWITCHING MEANS CONNECTED IN THE CIRCUIT OF SAID SEMICONDUCTOR TRIODE AND SAID POWER SOURCE AND ADAPTED TO PREPARE TRANSMISSION OF FORWARD OR BACK CURRENT TO A SECONDARY CLOCK CIRCUIT; AND COMMUTATOR MEANS CONTROLLING THE SWITCHING OF SAID SWITCHING MEANS AND THE TRANSMISSION OF NEGATIVE VOLTAGE TO THE BASE OF THE SAID TRIODE SO THAT THE SWITCHING MEANS IS SWITCHED OVER BEFORE NEGATIVE