CN2156630Y

CN2156630Y - Dialing device for limiting illegal using long distance telephone

Info

Publication number: CN2156630Y
Application number: CN 93225258
Authority: CN
Inventors: 吴震蒙
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-03-03
Filing date: 1993-03-03
Publication date: 1994-02-16
Anticipated expiration: 2003-03-03

Abstract

The utility model relates to a dialing device for limiting illegal long distance telephones, which is composed of a telephone keyboard, an output driver of a dialing pulse, an electronic switch, a voltage regulator, a discrimination and state maintaining device for a dialing plate for the first time, and a switch SW of a lock. The utility model is an easily operated device for limiting illegal long distance telephones; people can control the on-off of the lock so that the long distance telephones or short distance telephones can be communicated. In addition, the device has no influence on the impedance matching of a telephonic communication network. The utility model provides a dialing device for limiting illegal long distance telephones with the advantages of convenience, reliability and easy operation.

Description

Dialing device for limiting illegal using long distance telephone

The utility model relates to a kind of fornication trunk dialling device that limits.

At present, many telephone subscribers can both directly dial domestic, international long-distance.Because domestic, the international long-distance telephone expense is higher, therefore prevent from not obtain owner and agree to fornicate long-distance urgent day by day with the requirement that reduces unnecessary phone spending.At present domestic still do not have easy and simple to handlely can limit this long-distance class telephone set dialing mechanism of fornication.

The purpose of this utility model is that a kind of limited to the fornication trunk dialling device that can effectively control the fornication toll telephone easy and simple to handle will be provided, thereby guarantees that telephone charges only is used for necessary contact, reduces expenses.

The purpose of this utility model is achieved in that common telephone dialing device is by telephone keyboard, integrated dialer, the dial impulse output driver, electronic switch is formed, the utility model is the keyboard at common telephone dialing device, integrated dialer also connects a discriminating of dialing first and a state retainer that power supply is provided by pressurizer, this discriminator output that dials first is connected with integrated dialer by a tapered end switch, when the tapered end switch disconnects, dialing is first differentiated and is connected " disconnection " state that is in the function of integrated dialer with the state retainer, this can limit fornication trunk dialling device and plain old telephone dialing mechanism function and was as good as and can dials directly the world arbitrarily this moment, national distance, dial first during the tapered end switch closure and differentiate that being in function with state retainer and integrated dialer is connected " leading to " state, if push " 0 " key (world in the keyboard this moment behind the machine first, the first number average of National calls number is " 0 "), field effect transistor switch pipe in dialing discriminating first and the state retainer is in conducting state, and remains to the machine that next time rises by the oscillating crystal in the integrated dialing mechanism of tapered end switch short circuit and with this state.If playing what dial first behind the machine is non-" 0 " key in the keyboard, the disconnected state in field effect transistor switch pipe place in dialing discriminating first and the state retainer, this moment, the oscillating crystal in the integrated dialer was in normal operating conditions, and this state remained to played machine next time and take this to guarantee that the short distance conversation normally carries out.

Dialing first differentiates and the state retainer is made up of trigger, gate circuit, field effect transistor switch pipe and resistance, electric capacity, and this can be dialled first in case of necessity discriminating and state retainer are integrated into single chip.

For making stabilizer output voltage not be subjected to moment to play the influence of machine, guarantee that dialing is differentiated and state retainer steady operation first, be connected to one in the pressurizer and meet mutually opposite diode D with voltage-stabiliser tube.

The utlity model has following advantage: common phone is reequiped easy, and to telephone communication network impedance matching does not have influence.Easy and simple to handle reliably long-distance, short distance communication only need get final product with the tapered end switch transition, incoming call is called out have no effect.

Following embodiment and the accompanying drawing of former reason of the present utility model provides.

Accompanying drawing 1 is the embodiment block diagram of limited to the fornication trunk dialling device that provides according to the utility model.

Accompanying drawing 2 is for limiting the embodiment circuit diagram of fornication trunk dialling device.

Below in conjunction with embodiment accompanying drawing is illustrated:

Pressurizer (21) is by voltage-stabiliser tube DW, and resistance R 1, capacitor C 1 and diode D form.Diode D and voltage-stabiliser tube DW connect on the contrary to guarantee that the voltage on the C1 can not be to line discharge to guarantee FF1, FF2 and each gate circuit reliable operation when the instantaneous reduction of line voltage distribution, and exit 1 is the power supply of output end of pressure-stabilizing as trigger FF1, FF2 and each gate circuit.Dialing discriminating first and state retainer (22) are imported with a door G3, three inputs and a G1, two inputs or door G2, field effect transistor switch pipe T by trigger FF1, FF2, two and are provided the resistance R 2 of FF1, FF2 reset signal, capacitor C 2 to form.Telephone keyboard (23)-KB.Integrated dialer (24) is made up of integrated trigger DIL and oscillating crystal Cr.Dial impulse output driver (25) is made up of transistor T 2 and resistance R 4.Electronic switch then is made up of transistor T 1 and resistance R 3.HS is a switch hook, and this contact disconnected when telephone receiver hung up, and this closing of contact when telephone receiver is mentioned is provided the required power supply of telephone set and prepared dialing or conversation by telephone network.Whether the tapered end switch SW needs to block the selector switch of toll dialing.Line 4 ends lead to the telephone set communicator.The contact sets 2 of line 3 termination telephone hook switch.

The method of blocking dialing is that the oscillating crystal Cr in the integrated dialer of short circuit (24) makes it failure of oscillation, use a field effect transistor T in parallel with oscillating crystal Cr under tapered end switch SW closure state for this reason, when the y1 of trigger FF1 output high level, the conducting of field effect transistor switch pipe, oscillating crystal Cr by short circuit after failure of oscillation, the DP end of integrated trigger DIL does not have dial impulse output, otherwise when the y1 of trigger FF1 end output low level, field effect transistor switch pipe T ends, oscillating crystal Cr is not by short circuit, vibration continues, and the DP end of integrated trigger DIL can be exported dial impulse.

After pushing switch hook HS, trigger FF1 and FF2 reset, and y1 and y2 are low level,

1 He

2 is high level, and three inputs are in " unlatching " state with door G1, and at this moment, if at first button is promptly represented toll dialing for " 0 " key, the pin C2 of integrated trigger DIL and R4 are communicated with by pressing of " 0 " key.Therefore the level of this two pins is identical, will inevitably make pin C2 and R4 at DIL under to the effect of KB sweep signal all is high level, so it is high level that G3 is output as the D1 of high level trigger FF1, this changes the input that arrives G1 by G2 simultaneously, and the G1 that passes through " unlatching " arrives the T1 of FF1 and the T2 end of FF2, because this moment, the DP of DIL held no pulse output still, so be low level, the D2 end of FF2 is low level, so have only the FF1 rollover states to make y1 transfer high level to, field effect transistor switch pipe T conducting makes the oscillating crystal failure of oscillation, and the DP end of integrated trigger DIL can not be exported dial impulse.Since this moment FF1 1 pin has transferred low level to, and three inputs " are closed " with door G1, all can not change the state of trigger FF1, FF2 again by any key, until pushing switch hook HS once more trigger FF1, FF2 are resetted.If right and wrong " 0 " key of pushing for the first time, then the DP of integrated trigger DIL end has corresponding dial impulse output, this dial impulse drives electronic switch T1 work by the transistor T 2 of driver on the one hand, also makes trigger FF2 upset by the said same way as in front, makes like this 2 transfer low level to, and three inputs " are closed " because trigger FF1 does not have upset, so y1 still keeps low level, field effect transistor switch pipe T ends with door G1, and vibration continues, and by any key corresponding pulse output are arranged all.This state also will remain to and push once more till the switch hook HS.

G1 in the present embodiment, G2, G3, FF1, FF2 can realize with 4000 series or 74HC series cmos circuit, FF1, and FF2 can be combined into 74HC74 or with gate circuit.

Claims

1, a kind of fornication trunk dialling device that limits, comprise telephone keyboard (23), integrated dialer (24), dial impulse output driver (25), electronic switch (26), it is characterized in that: one provides the discriminating of dialing first of power supply and state retainer (22) to be connected to described keyboard (23), integrated dialer (24) by pressurizer (21), and described dialing is first differentiated and is connected with described integrated dialer (24) by the tapered end switch SW with state retainer (22) output.

2, the fornication trunk dialling device that limits according to claim 1 is characterized in that described dialing is first differentiated and state retainer (22) is made up of trigger, gate circuit, field effect transistor switch pipe, resistance, electric capacity.

3, the fornication trunk dialling device that limits according to claim 1 is characterized in that being connected in the described pressurizer (21) one and meets mutually opposite diode D with voltage-stabiliser tube.