CN102427351A

CN102427351A - Overlong timer for 555 time base circuit

Info

Publication number: CN102427351A
Application number: CN2011103979778A
Authority: CN
Inventors: 洪珍; 何林
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-12-05
Filing date: 2011-12-05
Publication date: 2012-04-25

Abstract

The invention relates to an overlong timer for a 555 time base circuit. The timer is composed of a 12 V direct-current power supply, a timing capacitor quick charge and slow discharge circuit, a monostable timing circuit, a control and alarm circuit and a working condition indicating circuit, wherein the type of the time base circuit IC1 in the monostable timing circuit is NE555. According to the overlong timer for a 555 time base circuit, the problems in the timing circuit designed by the time base circuit are solved, such as that the delay time of the circuit is difficult to exceed 40 minutes, and the leakage index of the timing capacitor is required to be very high otherwise the delay time of the circuit is greatly shortened. In the overlong timer for a 555 time base circuit, the good effect about the overlong delay of the circuit can be implemented by adopting the monostable timing circuit composed of the time base circuit, using electrolytic capacitors with common small capacity and potentiometers (resistors) with small resistance, and only adding two common elements. All elements of the overlong timer for a 555 time base circuit can be completely packed into a cassette with a 86 type faceplate so as to become a standard module for use by electricians.

Description

555 time-base circuit overlength timers

Technical field

The invention belongs to electronic technology and automatic control technology field, relate to a kind of 555 time-base circuit overlength timers.

Background technology

Time-base circuit is having purposes very widely aspect the automatic control of time-delay, still, time-base circuit is made circuit design and the manufacturing technology of time-delay above 40 minutes and is difficult to break through.In order to guarantee the reliability and the accuracy of time spent base circuit production delay circuit, time spent base circuit design making delay circuit delay time majority was controlled at below 40 minutes usually, made the scope of application of time-base circuit receive great limitation.

In order effectively to solve the technical barrier of not breaking through the time-base circuit ultra-delay all the time all the time; On the basis that does not change most time spent base circuit production time-delay typical circuits; The present invention only increases by 2 common components and parts in typical delay circuit, promptly realized the purpose of the ultra-delay of time spent base circuit production.

Below specify the correlation technique content that relate to of this 555 time-base circuit overlength timers in manufacturing process.

Summary of the invention

Goal of the invention and beneficial effect: 555 time-base circuit overlength timers of the present invention have thoroughly solved the timing circuit of time spent with basic circuit design; The circuit delay time was difficult to above 40 minutes; And to the high reality of timing capacitor electric leakage index request, otherwise the delay time of circuit will significantly shorten.The monostable circuit that time spent base circuit of the present invention is formed is used the electrochemical capacitor of common low capacity and the potentiometer of little resistance (resistance), and is only increased by 2 common components, has realized the good result of circuit ultra-delay.

Whole components and parts of 555 time-base circuit overlength timers can all be packed in the magazine of 86 profile plates, make it to become the standard module that the electrician uses and carry out the batch exploitation.

The circuit working principle: 555 time-base circuit overlength timers, in fact the core circuit of 555 time-base circuit overlength timers is monostable circuits, clicks key switch AN; The 12V DC power supply adds to the two ends of timing capacitor C1, and timing capacitor C1 is charged to 12V rapidly, and at this moment the base stage of NPN transistor VT has bias voltage; Make NPN transistor VT conducting; And then to make 2 pin of time-base circuit IC1 and 6 pin be high level, and then output 3 pin of time-base circuit IC1 are low level, and the coil of relay J gets the electrician and does; At this moment its normally opened contact J-1 adhesive is started working by the electrical equipment of normally opened contact J-1 control.

Along with the voltage on the timing capacitor C1 descends lentamente; 2 pin of time-base circuit IC1 and the voltage of 6 pin will descend gradually; When 2 pin of basic at that time IC circuit 1 and the voltage of 6 pin dropped to 2/3 supply voltage, output 3 pin of time-base circuit IC1 were high level by the low level upset, and at this moment the coil of relay J is not worked dead electricity; Then relay J normally opened contact J-1 discharges, and is at this moment quit work by the electrical appliance of normally opened contact J-1 control.

Technical characterictic: 555 time-base circuit overlength timers, to form by 12V DC power supply, timing capacitor quick charge and slow discharge circuit, mono-stable timing circuit, control and warning circuit, operating state indicating circuit, its characteristic comprises:

Timing capacitor quick charge and slow discharge circuit: form by key switch AN, timing capacitor C1, NPN transistor VT and potentiometer RP; The base stage of the termination NPN transistor VT of key switch AN, the positive pole of timing capacitor C1; The negative pole connection circuit ground GND of timing capacitor C1; The collector electrode of the other end of key switch AN, NPN transistor VT links to each other with the anodal VCC of 12V DC power supply; The emitter of NPN transistor VT connects the end of potentiometer RP, the other end of potentiometer RP and lever arm connection circuit ground GND thereof;

Mono-stable timing circuit: the model that time-base circuit IC1 adopts is NE555; 4 pin of time-base circuit IC1 and 8 pin meet 12V dc power anode VCC; 2 pin of time-base circuit IC1 and 6 pin connect the emitter of NPN transistor VT, the 1 pin connection circuit ground GND of time-base circuit IC1;

Control and warning circuit: 3 pin of time-base circuit IC1 connect an end of direct current relay J coil, the positive pole of protection diode D1 and the positive pole of buzzer YA; The negative pole connection circuit ground GND of buzzer YA, the negative pole of the other end of direct current relay J coil, protection diode D1 links to each other with the anodal VCC of 12V DC power supply;

Operating state indicating circuit: form by resistance R 1 and LED 1, resistance R 2 and LED 2; The negative pole of the 3 pin sending and receiving optical diode LED1 of time-base circuit IC1 and the positive pole of LED 2; Meet the anodal VCC of 12V DC power supply behind the cathode series resistance R1 of LED 1, connection circuit ground GND behind the negative pole series resistor R2 of LED 2.

Description of drawings

Accompanying drawing 1 is the circuit working schematic diagram of 555 time-base circuit overlength timers; J-1 in the accompanying drawing 1 is the normally opened contact of relay J.

Embodiment

Specification requirement according to circuit working schematic diagram shown in the accompanying drawing 1 and description of drawings and the following stated is implemented, and can realize the present invention.

The selection of components and parts and technical parameter

IC1 is a time-base circuit, and its model is: NE555; Time-base circuit IC1 is 8 pin DIP encapsulation, and each pin function: 1 pin is circuit ground GND; 2 pin are trigger end; 3 pin are output; 4 pin are reset terminal; 5 pin are control voltage; 6 pin are thresholding (threshold value); 7 pin are discharge end; 8 pin are dc power anode VCC;

Key switch AN can select the K-18 type for use; Timing capacitor C1 is an electrochemical capacitor, and capacity is 1000～2200 μ F/25V, requires timing capacitor C1 self leakage current more little good more; VT is a NPN transistor, and model 2SC9014 requires β value >=220;

RP is a linear potentiometer, and its resistance is 330K Ω; The resistance of resistance R 1, R2 is 910 Ω;

LED1 is a red light emitting diodes, and LED2 is a green LED;

YA is 9～12V buzzer, requires to include the electronics sounding circuit;

The model of relay J is JQX-13F-12V; Relay J has 5 pin, that is: 2 pin of coil of relay J, and power output has 3 pin, and 3 pin are formed normally opened contact and normally-closed contact respectively, and the J-1 in the accompanying drawing 1 is the normally opened contact of relay J.

Circuit production main points and debugging

Components and parts according on the circuit theory diagrams of 555 time-base circuit overlength timers in the accompanying drawing 1 connect method; The timing of circuit is confirmed by the value of timing capacitor C1, potentiometer RP; According to the time needs that the timing of electrical appliance is closed or regularly opened, the capacity of timing capacitor C1 can be selected in 1000 μ F to 2200 μ F scopes;

Conclusion (of pressure testing): selecting the capacity of timing capacitor C1 is 1000 μ F/25V, and when the resistance of linear potentiometer RP was 2.3K Ω, circuit delay was about 10 minutes; When the resistance of linear potentiometer RP was 22K Ω, time-delay was about 100 minutes; When the resistance of linear potentiometer RP was 52K Ω, circuit delay was 200 minutes; When the resistance of linear potentiometer RP is 250K Ω, when the capacity of timing capacitor C1 is 2200 μ F, about 48 hours of circuit delay.

Claims

1. a time-base circuit overlength timer is made up of 12V DC power supply, timing capacitor quick charge and slow discharge circuit, mono-stable timing circuit, control and warning circuit, operating state indicating circuit, and its characteristic comprises:

The timing capacitor quick charge is made up of key switch AN, timing capacitor C1, NPN transistor VT and potentiometer RP with slow discharge circuit; The base stage of the termination NPN transistor VT of key switch AN, the positive pole of timing capacitor C1; The negative pole connection circuit ground GND of timing capacitor C1; The collector electrode of the other end of key switch AN, NPN transistor VT links to each other with the anodal VCC of 12V DC power supply; The emitter of NPN transistor VT connects the end of potentiometer RP, the other end of potentiometer RP and lever arm connection circuit ground GND thereof;

The model that time-base circuit IC1 in the mono-stable timing circuit adopts is NE555; 4 pin of time-base circuit IC1 and 8 pin meet 12V dc power anode VCC; 2 pin of time-base circuit IC1 and 6 pin connect the emitter of NPN transistor VT, the 1 pin connection circuit ground GND of time-base circuit IC1;

3 pin of time-base circuit IC1 in control and the warning circuit connect an end of direct current relay J coil, the positive pole of protection diode D1 and the positive pole of buzzer YA; The negative pole connection circuit ground GND of buzzer YA, the negative pole of the other end of direct current relay J coil, protection diode D1 links to each other with the anodal VCC of 12V DC power supply;

The operating state indicating circuit is made up of resistance R 1 and LED 1, resistance R 2 and LED 2; The negative pole of the 3 pin sending and receiving optical diode LED1 of time-base circuit IC1 and the positive pole of LED 2; Meet the anodal VCC of 12V DC power supply behind the cathode series resistance R1 of LED 1, connection circuit ground GND behind the negative pole series resistor R2 of LED 2.