JPS60112389A - C position circuit of trunk circuit - Google Patents

Abstract

PURPOSE:To obtain a C position circuit while using an inexpensive miniature relay by charging discharging the second condenser by the output of the first detection circuit, inputting the discharge into a comparator, and driving a C position relay by the output of the second detection circuit. CONSTITUTION:When a dial pulse is sent out by changing a switch SWO OFF ON OFF ON..., a charging current flows a condenser CC2. This charging current of said CC2 flows when SWO changes from on to off, therefore the minus input of a comparator CMO exceeds a plus input to which comparison voltage is added to. The excess makes a condenser CC3 discharge via a diode D1. Because the CC3 is made to discharge gradually by a resistor R6 placed between power sources, the CC3 does not add voltage exceeding the comparison voltage to the plus input of a comparator CM1. Therefore, the CM1 does not change and a trasistor Q0 continues on-state.

Description

TECHNICAL FIELD The present invention relates to a C-position circuit in the trunk of a switch.

(Background technology) Conventionally, the logic of the C position circuit of the trunk has been incorporated by relay contacts, and as shown in Figure 1, the A relay for dial transmission operates when the A relay is activated, and the slow recovery circuit is activated by the self contact. Connect and perform slow recovery (]] B
It consists of a position relay and a C position relay that operates only when the A relay is activated and performs a slow recovery by connecting a slow recovery circuit with a self-contact. When the A relay is activated, only the B position relay operates. When transmitting dial pulses by switching on and off the A relay, both the B position relay and the C position relay operate, and the contact of the C position relay prevents distortion of the dial pulse due to the capacitor in the communication circuit. Operate.

However, since the logic is implemented through relay contacts, a multi-contact relay is required, which has the drawback of increasing the price and size.

(Problem of the Invention) An object of the present invention is to obtain a C-position circuit using an inexpensive miniature relay.

(Summary of the Invention) The main point of the present invention is that the A relay drive signal is input to a first detection circuit using a comparator by capacitor coupling, and the first detection circuit detects changes from the operation of the A relay to the second detection circuit. Furthermore, a C-position circuit is provided in which the output is inputted to a second detection circuit using a comparator and the C-position relay is driven by the output of the second detection circuit.

(Structure and operation of the invention) FIG. 2 shows a circuit showing an embodiment of the invention, in which the switch SW
O is connected to the A relay drive line, and further connected to the capacitor CG
2 to the negative input of the comparator CMO. The negative input of comparator CMO is simultaneously connected by resistor R2 and diode 00. Diode DO is for human power protection of comparator CMO. The positive input of the comparator CMO is connected to the source tlj through a resistor R3 and at the same time is placed through a resistor R4 to form a comparator JE (Vr[, p l ). There is a capacitor 003 between the positive power of the comparator CMI and the ground, and it is connected to the power supply by the resistor R6, and is connected to the power supply by the resistor R5.
and is connected to the output of the comparator CMO through a diode D1. The negative input of the comparator CMI is connected to the power supply through a resistor R7 and to the ground through a resistor R8, and serves as a comparison voltage (Vrl, 2).

When the switch SWO is turned on, the A relay drive line is installed and the A relay operates. At the same time capacitor CC2
is installed and is discharged through the diode DO, and a negative potential is applied to the negative voltage of the comparator CMG. However, the comparison voltage (
VrεF+), and the comparator CMO
The output of does not change.

Therefore, the capacitor CC3 connected to the positive input of the comparator CMI will not be discharged, and the transistor Q connected to the comparator C through the resistor R8 will not discharge.
O does not turn on.

Next, turn switch SWO OFF → ON → OFF → ON...
・When transmitting dial pulses by changing ・, charging current flows to capacitor CC2,
1jf, 1jl are charged to the resistor R2 placed between and ground.

A voltage proportional to the current is generated and applied to the negative input of comparator CMO. When the capacitor CC2 is charged, the negative input of the comparator CMO becomes the ground potential because there is no charging current.

The charging current of this capacitor CG2 is
When the voltage changes from N to OFF, the negative voltage of the comparator CMO exceeds the positive input to which the comparison voltage (Vr large p+) is applied, and its output discharges the capacitor CC3 through the resistor R5 and diode D1. The capacitor CC3 is connected to the positive input of the comparator CHI, and when the capacitor CC3 discharges, the positive input of the comparator CM1 goes below the negative human power comparison voltage (Vrgpz), and the comparator GMI operates and is connected to the transistor QO through the resistor R8. Supplying base current turns on transistor QO. At this time, relay C operates. Next, if we look at the operation of the ON time during the OFF->ON->OFF change of the switch SW, the comparator CMO is turned off because the capacitor CG2 is charged. However, since the capacitor CC3 is gradually charged by the resistor R6 placed between it and the power supply, a voltage exceeding the comparison voltage (Vrap2) is not applied to the positive input of the comparator CMI. Therefore, comparator G
MI does not change and transistor QO continues to be turned on.

Figure 3 is a time chart I showing the operation of each part in Figure 2.
This shows the operation of switch 0 from -12, the A relay drive signal, the negative input of comparator GMO, the positive input of comparator C old, and the collector of transistor QO.

(Effects of the Invention) As explained above, the present invention provides an A relay drive signal that is connected to a first detection circuit using a comparator by capacitor coupling. A C-position circuit is provided which detects the current, charges and discharges a second capacitor based on its output, inputs it to a second detection circuit using a comparator, and drives a C-position relay using the output of the second detection circuit. (1) An inexpensive miniature relay can be used, and the shape is small. (2) The C relay operates only during dialing, which saves power. (3) No need for a B positive 95 circuit. (4) Even if a miniature relay is used, the C relay can be used. This has the advantage that the position circuit does not require program control.

[Brief explanation of the drawing]

51 shows a conventional C position circuit, FIG. 2 shows a circuit diagram of an embodiment of the present invention, and FIG. 3 shows an operation time chart of each part of FIG. 2. Special Fraud Issuer 1 Person Oki Electric Industry Co., Ltd. Patent Application Agent B C Riju Landscape 7 Mountains - Figure 2 Figure 3 Figure 4 Leopard

Claims (1)

[Claims] In the C position circuit of the L-rank circuit, the A relay drive signal is manually input to the comparator by capacitor coupling, and the first detection circuit detects the change point of "1]" and the output of the first detection circuit. charging and discharging a second capacitor, inputting the second capacitor to a comparator, having a second detection circuit forming a slow recovery circuit, and driving a C position relay by the output of the second detection circuit. C characterized by
position circuit.