JPS5816100Y2 - digital timer device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a digital timer device for a DC power supply, which has a built-in clock pulse generation circuit and an electromagnetic relay in its output circuit.

Digital timers differ from analog timers in that they do not cause setting errors because the time is set digitally using a switch.Digital timers have an accurate cycle and use lock pulses, making them highly accurate for a wide range of time settings from short to long periods. It is used as a precision timer.

However, if the operating time of the electromagnetic relay in the output circuit cannot be ignored compared to the installation time, for example, the operating time of the output electromagnetic relay is 0.05 seconds, the clock pulse period is 0.1 seconds, and the minimum If the set time is 0.1 seconds, the operating time as a digital timer is 0.15 seconds because the operating time of the output electromagnetic relay is added to the clock pulse period of 0.1 seconds, which is a very large operating time error. will occur.

Even if the set time is 1 second, an error of 5 points still occurs.

On the other hand, in an analog timer, each setting value is graduated according to the actual working time, so the above-mentioned drawback does not occur, but there is a drawback that a setting error occurs.

This proposal was made in order to eliminate the drawbacks of the digital timer described above, and in a digital timer for DC power supply that can set a time equal to the clock pulse period as the minimum time setting, a lock signal is generated for a certain period of time from startup,
A digital counter and a clock pulse generation circuit are applied to lock the activation, and the clock pulse is generated immediately after the lock signal disappears, and when the minimum time is set, the time from activation to the disappearance of the low clock signal T is the first wave of the clock pulse. T is the time it takes for the output electromagnetic relay to operate and close its output contact.

'', the respective times TL and T.

Provided is a digital timer device characterized in that by making the sum equal to the minimum setting time, no difference in operating time due to the operating time T of the output electromagnetic relay occurs at any operating time setting. It is something to do.

FIG. 1 is a block diagram of a digital melt timer device that has a clock pulse generation circuit with a period of T seconds and can set time at intervals of T seconds between T and 9To seconds as an embodiment of the present invention. .

In FIG. 1, S is an external contact for starting the digital timer of the present invention, L is a circuit that generates a lock signal output for T seconds after the contact S is closed, and CP is a cycle T.

Second clock pulse generation circuit, C is 1 in decimal counter
9 is a count output terminal of the counter C, SW is a switch that selects the count output terminal of the counter C in accordance with a set time, and A is an amplification circuit that amplifies the output of the selection switch SW. energizes electromagnetic relay X.

FIG. 2 is a mayme chart of the operation of the embodiment of the present invention shown in FIG.
This figure shows the case where the waveform generation section is set to 1, and since the symbols of each waveform generating section are the same as those in FIG. 1, the explanation will be omitted.

The operation of the embodiment of the present invention will be described in detail in FIG. 1. When the start condition is applied from the outside and the contact S closes, the lock signal generation circuit generates an output for T seconds, and the output clears the digital counter C. Together with this, activation of the clock pulse generation circuit CP is locked.

Immediately after the lock signal generating circuit is reset after T seconds have passed since the contact S is closed, the clock pulse generating circuit CP is activated.

In this state, when the switch SW selects the output terminal 1 of the counter C, the output terminal 1 of the counter C becomes "O" due to the first wave of the output of the clock pulse generation circuit CP.
becomes “1” and passes through the switch SW to the amplifier circuit A.
The output electromagnetic relay X is energized, and the output electromagnetic relay X generates a contact output after an operating time To seconds.

Now, by adjusting the output duration time TL seconds of the lock signal generation circuit and making the sum with the operating time T seconds of the output electromagnetic relay X equal to the clock pulse period T seconds, as shown in FIG. As shown in a, the time from when the starting condition contact S closes to when the output electromagnetic relay X operates and generates the contact output is T seconds.

Next, by selecting the output terminal 2 of the counter C with the switch SW, the clock pulse generation circuit CP
At the second wave of the output of the counter C, the output terminal 2 of the counter C becomes 10.
The operation time as a timer is 2TC seconds as shown in FIG.

Similarly, the output terminal n of the counter C (3≦n<
g) is selected by the switch SW.

As shown in FIG. 2C, the digital timer of the present invention operates in n76 seconds.

As detailed above, according to the present invention, even if a large capacity electromagnetic relay is provided in the output circuit and the operating time is set to be so short that the operating time cannot be ignored.

It is possible to provide a digital timer device for a DC power supply that operates at an accurate set time including the operation time of the output electromagnetic relay.

In this embodiment, a digital timer with a simple configuration and a one-digit time setting is shown. However, a digital counter and a switch for selecting the output terminal of the counter are added, and the coincidence of the outputs of a plurality of the switches is detected. It is no longer the case that by adding circuits, it is possible to realize a digital timer device that can set a wide range of operating times of multiple digits and that does not generate operating time errors.

In addition, in this proposal, the output electromagnetic relay operates in a pulsed manner, but if continuous contact output is required until a reset operation is performed, the output electromagnetic relay may be self-holding, or a memory circuit may be installed between the selection switch and the amplification circuit. It is also well known that a purpose can be achieved by inserting it.

Furthermore, although an AC power source is not required in the present invention, it is of course possible to use a DC power source obtained from an AC power source via a rectifier circuit.

[Brief explanation of the drawing]

FIG. 1 shows a block diagram of an embodiment of the present invention. FIG. 2 shows an operational meme chart of the embodiment shown in FIG. S...External contact for starting, L...Lock signal generation circuit, CP...Clock pulse generation circuit, C...Digital counter, 1 to 9. ...
...Digital counter output terminal, SW...Switch circuit, A...Width amplification circuit, X...Electromagnetic relay.

Claims (1)

[Claims for Utility Model Registration] A clock pulse generation circuit that generates clock pulses with a period of T seconds; a digital counter that counts the number of clock pulses generated by the clock pulse generation circuit;
a switch circuit that selects an output terminal for outputting each count result of the counter in accordance with a set operating time;
An amplification circuit that amplifies the count result output of the counter obtained via the switch circuit, and an operation for T seconds after being excited by the amplification circuit output. In a digital timer device for a DC power supply consisting of an electromagnetic relay that generates a contact output, a lock signal generation circuit generates a lock signal for TL seconds from startup to reset the counter and locks the operation of the clock pulse generation circuit. and a period T of the clock pulse. seconds, the operating time To seconds of the electromagnetic relay, and the opening of the lock signal generation circuit? T + during the signal duration T seconds
A digital timer device characterized by having the relationship T = T.