Timer device controlled by a switch

Abstract

According to the timer device of the invention, a time-setting part supplied from the power supply sets up the period from the opening instance of said switch to the instance that the magnitude of current in the capacitor comes down under a specified value, as said current-supply period, and a current-controlling part allows the current to flow from said power supply to said load during said current-supply period determined by said time-setting part, and a switch makes the time-setting part operate at opening instance of the switch.Therefore, the timer device of the invention can reduce the loss of power during the waiting period. And when the magnitude of the current flowing through the time-setting part and the current-controlling part in open-state of the switch, in order that the decrement of the current in the current-controlling part makes the current in the time-setting part rapidly decrease, these parts are interconnected with each other.The timer device of the invention as mentioned above provide effects that it can reduce the recovering time to prepare for the sequential operation, and makes the magnitude of the current supplied from the power supply to the load stable.

Description

Claims

1. A timer device for controlling the current supplied from a power supply to a load using an on/off switch, the timer device comprising:

a time-setting part which is charged by the current flowing from said power supply, said time-setting part setting up a load current-supply period during which the current can flow between said power supply and said load;

a current-controlling part which controls the current to flow from said power supply to said load during said load current-supply period determined by said time-setting part; and

an on/off switch which controls said time-setting part to start to operate at the opening instance thereof.

2. A timer device according to claim 1, characterized in that said time-setting part is charged by said power supply when said switch is in an open-state, wherein said time-setting part starts to be discharged when the switch is closed, and wherein said load current-supply period is determined by the period of time from the opening instance of said switch to the instance that the magnitude of the current in the capacitor comes down a specified value.

3. A timer device according to claim 2, characterized in that said time-setting part comprises:

a capacitor charged by said power supply;

a diode disposed between a positive electrode of said power supply and said capacitor with reverse-biased connection to said power supply;

a PNP transistor which has its emitter connected to said power supply and said load, and its base connected to the node disposed between said diode and said capacitor; and

a first resistor disposed between the negative electrode of said power supply and said capacitor, and

said current-controlling part comprises:

an NPN transistor which has its base connected to the collector of said PNP transistor and the negative electrode of said power supply, and its emitter connected to the negative electrode of said power supply, and its collector connected to said load,

whereby said current-controlling part has no current flow from said power supply to said load if the magnitude of the current flowed through the collector of said PNP transistor in open-state of said switch comes down under a specified value.

4. A timer device according to claim 2, characterized in that said time-setting part comprises:

a capacitor charged by said power supply;

a diode disposed between a positive electrode of said power supply and said capacitor with reverse-biased connection to said power supply;

a PNP transistor which has its emitter connected to the positive electrode of said power supply and said load, and its base connected to the node disposed between said diode and said capacitor; and

a first resistor which connects said NPN transistor with said capacitor, and

said current-controlling part comprises:

an NPN transistor which has its base connected to the negative electrode of said power supply, and its collector connected to said load;

and a second resistor disposed between the collector and the emitter of said NPN transistor,

whereby said current-controlling part has no current flow from said power supply to said load if the magnitude of the current flowed through the collector of said PNP transistor in open-state of said switch comes down under a specified value.

5. A timer device according to claim 3, characterized in that one terminal of said switch is connected to the node disposed between the positive electrode of said power supply and said diode, and the other terminal of said switch is connected to the node disposed between the negative electrode of said power supply and said capacitor.

6. A timer device according to claim 4, characterized in that one terminal of said switch is connected to the node disposed between the positive electrode of said power supply and said diode, and the other terminal of said switch is connected to the node disposed between the negative electrode of said power supply and said capacitor.