CN201177648Y

CN201177648Y - Motor rotation-blocking detection circuit for electrical appliance

Info

Publication number: CN201177648Y
Application number: CNU200820092288XU
Authority: CN
Inventors: 姜西辉; 刘建伟; 蒋洪波
Original assignee: Shenzhen H&T Intelligent Control Co Ltd
Current assignee: Shenzhen H&T Intelligent Control Co Ltd
Priority date: 2008-02-19
Filing date: 2008-02-19
Publication date: 2009-01-07
Anticipated expiration: 2018-02-19

Abstract

The utility model discloses a motor rotation-clogging detection circuit for a home appliance controller, which comprises a motor, and a silicon controlled rectifier connected with the motor for controlling the rotation of the motor, wherein the motor rotation-clogging detection circuit further includes a photoelectric coupler; the positive electrode at the input terminal of the photoelectric coupler is connected with the silicon controlled rectifier; the negative electrode at the input terminal is connected with the motor through a current limiting resistor; and the output terminal is connected with a controller. The motor rotation-clogging detection circuit has the advantages of low cost, small occupied area and reduced size, and can achieve isolation of heavy current and weak current.

Description

The motor rotation blockage testing circuit that is used for domestic electric appliances controller

Technical field

The utility model relates to household electrical appliances control technology field, relates in particular to a kind of motor rotation blockage testing circuit that is used for domestic electric appliances controller.

Background technology

For the household electrical appliance that use machine operation, be to guarantee one of important means of household electrical appliance safety to the protection of motor rotation blockage, in addition,, also require further to realize the isolation of forceful electric power and light current for some household electrical appliance.The motor rotation blockage holding circuit great majority that are used for domestic electric appliances controller of prior art are to utilize current transformer to realize detection and protection to motor rotation blockage, in addition, also having some is to utilize the resistance step-down to realize detection and protection to motor rotation blockage, and the shortcoming of these schemes is: the cost of current transformer is higher; Though and employing resistance drop pressure type cost is lower, can not realize the isolation of forceful electric power and light current.

The utility model content

Technical problem to be solved in the utility model is: a kind of motor rotation blockage testing circuit that is used for domestic electric appliances controller is provided, and this circuit cost is low, and it is little to take up room, and can realize the isolation of forceful electric power and light current in the household electrical appliances.

For solving the problems of the technologies described above, the utility model adopts following technical scheme:

A kind of motor rotation blockage testing circuit that is used for domestic electric appliances controller, comprise motor and link to each other, be used to control the controllable silicon that motor rotates with described motor, the input anode that described motor rotation blockage testing circuit also is provided with a photoelectrical coupler, described photoelectrical coupler links to each other with controllable silicon, input cathode links to each other with motor by a current-limiting resistance, and its output terminal links to each other with controller.

The beneficial effects of the utility model are:

Embodiment of the present utility model realizes detection and protection to motor rotation blockage by adopting photoelectrical coupler and resistance step-down, and this circuit cost is low, and it is little to take up room, and has reduced the volume of product, has realized the isolation of forceful electric power and light current again.

Below in conjunction with accompanying drawing the utility model is described in further detail.

Description of drawings

Fig. 1 is the circuit theory diagrams of the embodiment of motor rotation blockage testing circuit who is used for domestic electric appliances controller that provides of the utility model.

Embodiment

With reference to figure 1, this figure is the circuit theory diagrams of the embodiment of motor rotation blockage testing circuit who is used for domestic electric appliances controller that provides of the utility model; As shown in the figure, this circuit comprises motor M OTOR and links to each other with described motor, is used to control the controllable silicon SCR that motor rotates that the trigger electrode of controllable silicon SCR is connected the port I/O2 of controller; This circuit also is provided with the emission side of a photoelectrical coupler (hereinafter to be referred as optocoupler) OPT, optocoupler OPT, the positive pole that is input end links to each other with controllable silicon, the negative pole of input end links to each other with motor M OTOR by a current-limiting resistance R1, between described current-limiting resistance R1 and motor M OTOR, also be connected with a diode D1 from optocoupler OPT to the unidirectional conducting of motor M OTOR direction, the effect of diode D1 is protection optocoupler OPT, prevents that alternating current from passing through optocoupler OPT and with its damage; And the sensitization side of optocoupler OPT, promptly output terminal links to each other with the port I/O1 of controller.

In addition, also be provided with the pull down resistor R2 of an end ground connection between the output terminal of described photoelectrical coupler and controller, the main effect of resistance R 2 is to get high-low level to give controller; Also be provided with voltage sampling resistor R3 between the input end of optocoupler OPT and the controllable silicon SCR, the effect of resistance R 3 is to provide forward voltage for optocoupler.

Describe the principle of work of present embodiment below in detail.

When the electric main of 220VAC is added in the two ends of ACL and ACN and controller to the trigger electrode I/O2 of controllable silicon SCR output trigger pip, the controllable silicon SCR conducting, motor M OTOR rotates.Under motor M OTOR normal operation, voltage difference among Fig. 1 between 2 of a and the b be the product of electric current I a and resistance R 3 and the normal tube voltage drop of silicon controlled (about 1.5V) and, be Uab=Ia*R3+1.5V, suitably choose the resistance of R1, make diode not conducting under normal voltage Uab of optocoupler OPT emission side, then the sensitization side joint of optocoupler OPT can not receive light and is in cut-off state, this moment, the signal that exports controller to of I/O1 was a low level, controller then continues to export trigger pip makes its conducting to controllable silicon SCR, and motor M OTOR runs well; And when motor M OTOR owing to load is excessive stall takes place, the electric current that flows through motor motor M OTOR, controllable silicon SCR and resistance R 3 can increase sharply, the voltage that causes illustrating between 2 of a and the b increases sharply, impel the diode current flow of optocoupler OPT emission side, thereby further make the conducting of optocoupler OPT sensitization side, the signal that causes I/O1 to export controller to becomes high level, and controller is when receiving the high level signal that I/O1 sends here, then cancel the silicon controlled trigger pip at once, the electric current that cut-out increases sharply, thus prevent that motor is owing to stall burns.

The utility model cost is low, and it is little to take up room, and has reduced the volume of product, and because the isolation characteristic of optocoupler, realized the isolation of forceful electric power and light current again, can be applicable on the circuit of household electrical appliance such as stirring machine, fruit juice mixer, be used for preventing that motor from burning because of long-time stall heating.

The above is a preferred implementation of the present utility model; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the utility model principle; can also make some improvements and modifications, these improvements and modifications also are considered as protection domain of the present utility model.

Claims

1, a kind of motor rotation blockage testing circuit that is used for domestic electric appliances controller, comprise motor and link to each other, be used to control the controllable silicon that motor rotates with described motor, it is characterized in that: the input anode that described motor rotation blockage testing circuit also is provided with a photoelectrical coupler, described photoelectrical coupler links to each other with controllable silicon, input cathode links to each other with motor by a current-limiting resistance, and its output terminal links to each other with controller.

2, the motor rotation blockage testing circuit that is used for domestic electric appliances controller as claimed in claim 1 is characterized in that, also is connected with the diode of a unidirectional conducting from the photoelectrical coupler to the motor drive direction between described current-limiting resistance and motor.

3, the motor rotation blockage testing circuit that is used for domestic electric appliances controller as claimed in claim 1 or 2 is characterized in that, also is provided with a voltage sampling resistor between the input end of described photoelectrical coupler and controllable silicon.

4, the motor rotation blockage testing circuit that is used for domestic electric appliances controller as claimed in claim 1 or 2 is characterized in that, also is provided with the pull down resistor of holding ground connection one by one between the output terminal of described photoelectrical coupler and controller.