JPS5950137B2 - timer circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention allows arbitrary time settings to be made independently by a plurality of variable resistors, and by a selection switch.
This relates to an electronic timer circuit that allows one hour to be selected from one of these timers, and its purpose is (1) to adjust the set time of each variable resistor due to variations in the resistance values of the multiple variable resistors used. To reduce the variation in the setting time of the entire device as much as possible, and to simplify the adjustment and correction during the manufacturing process.

(2) The change characteristics of the setting time with respect to the rotation angle (or slide position) of the variable resistor for time setting can be relatively easily selected without using a special variable resistor. performance and characteristics of high precision.

(3) The structure is simple and can be realized at low cost.

etc. Conventionally, in timer circuits where time can be set using a variable resistor, a fixed resistor or semi-fixed resistor is connected in series or parallel to the variable resistor in order to compensate for variations in the resistance value of the variable resistor. Then, the combined resistance value is adjusted to a predetermined value, or the potential of the terminal to which the reference voltage is applied is adjusted.

However, when trying to configure a timer circuit that can be preset independently using multiple variable resistors, it is necessary to perform adjustment using the conventional method for each variable resistor. Moreover, the circuit configuration becomes complicated.

Also, when adding a resistor in series with a variable resistor, the minimum setting time will vary due to variations in the resistance value of the variable resistor, and when adding a resistor in parallel to the variable resistor, The resistance value change characteristic with respect to the rotation angle of the variable resistor changes due to the variation in the resistance value of the variable resistor, and the change is also inconsistent.

Therefore, if you try to configure a timer circuit that can preset one hour each timer using multiple variable resistors using the conventional method, you will encounter various problems such as non-uniformity of characteristics, increased cost of adjustment and correction processes, and complexity of the configuration. This will cause problems.

Therefore, the present invention solves the above-mentioned problems and provides a timer circuit that is economically superior in terms of characteristics, cost, mass productivity, etc.

FIG. 1 shows an embodiment of a timer circuit according to the present invention.

In Figure 1, 1 is a DC power supply, 2 is a power switch, and 3
4 is a resistor, 4 is a circuit correction resistor, and 5 is a capacitor that is charged from a DC power supply via resistors 3 and 4.

A charging circuit A is constituted by resistors 3 and 4 and a capacitor 5.

6, 7. Reference numeral 8 denotes a fixed resistor, and the tolerance for variation in resistance value of each resistor is selected to be the same (for example, ±2%).

9, 10, and 11 are variable resistors for time setting, respectively.

These fixed resistors6. 7. 8 and variable resistor 9, 10
．． 11 constitutes a time setting circuit, and variable resistor 9゜1
The voltage to be preset from each sliding terminal of 0.11 ed1. ed2. Output ed3.

Note that since the sliding terminals of the variable resistors 9, 10, and 11 are not directly connected to the two terminal terminals that give the total resistance value, the sliding of the sliding terminals causes the difference between the two terminal terminals. This is a configuration in which the resistance value does not change.

12 is a three-contact selection switch, which selects three preset voltages ed□, ed2. It selects one of ed3 and outputs it as a set voltage ed that determines one hour of the timer.

13 is a comparator, and capacitor 5 of charging circuit A
The charging voltage ec and the set voltage ed selected by the selection switch 12 are input, and when ec > ed, the output voltage V.

is inverted from the bi level to the low level, and this comparator 13 constitutes a voltage comparison circuit C.

14.15 is a resistor, 16 is a transistor, 17 is a relay, 18 is a diode for surge absorption, and these are:
Depending on the output of the comparator 13, the relay 17 is turned on and off.
It constitutes a drive circuit that turns off.

In the above configuration, the charging circuit 4 charges the capacitor 5 through the resistors 3 and 4 after the power switch 2 is turned on, and as shown in FIG.
It changes depending on.

In the figure, the charging voltage ec at time 1=11
is VL, ec at t=t2 is VH, and time 1 is
= The time from 0 to tl is the minimum setting value TL of the timer one hour T, and the time from time 1 = 0 to t2 is the timer one hour T.
The maximum setting value TH is set as TH.

Therefore, the time setting circuit B is configured such that, for example, the minimum value of the voltage ed1 at the sliding terminal of the variable resistor 9 is VL, and the maximum value is □. Then, when the voltage ed1=Vt is given, the charging voltage ec of the capacitor 5 becomes equal to the voltage ed after the time t=j1, that is, after one time T=TL of the timer, after the power switch 2 is turned on.

Furthermore, when the voltage ed=VH is given, the charging voltage ec and the voltage ed1 similarly become equal after one time T''TH of the timer.

Therefore, the selection switch 12 is connected to the terminal S0 and the common terminal S.

If the set voltage ed input to the comparator 13 becomes equal to the voltage ed1, the voltage e
Depending on the value of d□, that is, if edl = V t, after one timer time T = TL, if edl = VH, after one timer time T = T, then ed < ec, and the output voltage V .

becomes low level from the by level, and the relay 17 is turned on immediately after the power switch 2 is turned on and turned off after one hour T according to the voltage ed1.

This operation is exactly the same when the selection switch 12 is set to the S2 terminal and the S3 terminal, and the voltage ed2 or ed3 is set to the set voltage ed.

Therefore, in the time setting circuit B, three variable resistors 9,
10. The voltage obtained at each sliding terminal of 11 ed1
．． ed2. When ed3 is varied from VL to VH, that is, as shown in FIG.
When the rotation angle θ (slide position in the case of sliding terminals) of sliding terminals 10 and 11 is varied from 0% to 100%, timer one hour T = set any timer one hour T between TL and TH. You can.

If we assume that the resistance change characteristics of the three variable resistors 9, 10, and 11 with respect to the rotation angle θ are linear, then the timer time T with respect to the rotation angle θ can be immediately calculated from Fig. 2 as shown in Fig. 3. characteristics, and the variable resistors 9, 10 and 11 of 3 can be preset independently,
When one of these values is selected by the selection switch 12, the relay 17 is operated at one time T of the timer.

Next, in time setting circuit B, three variable resistors 9, 1
The same total resistance value of 0.11 and the same tolerance value for variation are selected, and the tolerance value for variation is selected to be ±20% of the standard value.

On the other hand, fixed resistor 6. 7. 8 is selected to have a small variation of ±2%.

Then, the total resistance value of the variable resistor is RVΩ1, the tolerance value of the variable resistor is ±KV (maximum), the three variable resistors 9,
10° When the resistance value of the fixed resistor 7 in parallel with 11 is RpΩ, and the tolerance for its variation is ±KpF1, (however, n
is the number of variable resistors, and is selected so that n=3), that is, in this case.

By selecting such a relationship, the range of variations in voltages vL and VH caused by variations in the total resistance values of the three variable resistors 9, 10, and 11 is the same as that caused by variations in the resistance value of the fixed resistor 7. can be made smaller than.

From this, even if the total resistance values of the three variable resistors 9, 10, and 11 vary by 20% in the same direction, it is equivalent to a variation of 2% in the resistance value of the fixed resistor 7. It can be considered that it is less than that, and as a result, the variation in the total resistance value of the variable resistors 9, 10, and 11 is extremely reduced.

As a result, the time setting circuit B can provide the maximum value VH and minimum value VL of the set voltage with high accuracy while using an ordinary variable resistor with large variations.

And the voltages ed,, ed2. at the respective sliding terminals of the variable resistors 9, 10, 11. ed3 changes continuously and linearly from the minimum value vL to the maximum value VH depending on the rotation angle θ, and it is possible to obtain the characteristics of the timer one time T as shown in FIG. 3 described above.

Note that the circuit correction resistor 4 of the charging circuit A is used to correct variations that are a combination of variations in the capacitor 5 and slight variations in the time setting circuit B, and can correct circuit variations with only one adjustment. It's going to be a long time ago.

Note that in this embodiment, three variable resistors 9, 10,
No. 11 has the same total resistance value and tolerance for variation, but in some cases they may not be the same, and in such cases, both of these variable resistors have the same total resistance value. The variation in the voltages ■ and ■□ that occurs when the maximum variation occurs in the same direction is greater than the value that occurs when the resistance value of the fixed resistor 7 connected in parallel with them causes the maximum variation. The resistance value of the fixed resistor 7 and the tolerance value of its variation should be selected so that the resistance value of the fixed resistor 7 and the tolerance value of the variation thereof are selected so that the tolerance value of the variation of the fixed resistor 6 and 8 is usually set to the same value as that of the fixed resistor 7. Although it is appropriate, calculate the influence of these fixed resistors 6 and 8 on the voltages VL and VH, and choose one with an allowable value of 1 bar that is equal to or less than the influence of fixed resistor 7. If selected, it is thought that the design will be rational in terms of characteristics and cost.

Furthermore, in the embodiment of FIG. 1, three variable resistors 9, 1
0.11, three timer hours T can be preset, but the number to be preset can be arbitrarily determined, and the variable resistor of that number is connected in the same way, and the selection switch 12 is The number of contacts may be selected to correspond to this, and the structure may be configured so as to satisfy equation (1).

Next, FIG. 4 shows another embodiment.

FIG. 4 shows a time setting circuit B, and other parts are the same as those in FIG. 1.

In the figure, 7a and 7b are fixed resistors and 9'.

10', 11' are both variable resistors, 19, 20 .
21 are variable resistors 9', 10', and 11, respectively.
It is the center tap of ', and is a terminal that provides a resistance value of 50% of the total resistance value.

These three center taps 19, 20, and 21 are connected to the connection points of fixed resistors 7a and 7b, respectively.

and the voltages VL and VH are the same as those in FIG.
Moreover, the voltage VM at the connection point between the fixed resistors 7a and 7b is
In FIG. 2, the timer time T is selected to be the intermediate value between TL and TH.

With this configuration, the variable resistor 9'. 10', 1
If the sliding terminals are set at the center taps 19°20.21 of 1', the position, that is, the rotation angle θ
=50%, the timer one time T becomes the intermediate value TM between the minimum value TL and the maximum value TH, as shown in the characteristic in FIG.

Note that the characteristic L' in FIG. 5 shows a straight line.

Therefore, in this embodiment, the rotation angle θ and the timer time T
The relationship is more linear than the relationship in the embodiment shown in FIG. 1 (FIG. 3), and the relationship between Even if variations occur in the linearity of the resistance change characteristics, the voltage is fixed at the voltage VM at the center tap position, that is, at the rotation angle θ=50%, and the variations are greatly reduced.

In this embodiment, variable resistors 9', 10', 1
1' and the fixed resistors 7a and 7b, for example, for the fixed resistor 7a, the total resistance value is determined from the center tap position of each of the variable resistors 9', 10', and 11' that are in a parallel relationship with the fixed resistor 7a. The relationship between the resistance value (=172 of the total resistance value) and the tolerance value of its variation between the terminal terminal and the resistance value of the fixed resistor 7a and the tolerance value of its variation is expressed by equation (1). By selecting the resistor 7b in accordance with
This will greatly reduce the variation in the total resistance values of the three variable resistors 9', 10', and 11'.

Next, FIG. 6 shows still another embodiment.

FIG. 6 shows a time setting circuit B, and the other parts are the same as in FIG. 1 (other circuits are omitted).

In the figure, -22, 23, 24, 25, and 26 are fixed resistors, and 27, 28, and 29 are variable resistors, respectively.

The variable resistors 27, 28, and 29 are fixed resistors 2 and 29, respectively.
3. 24. 25 in parallel, and the voltage at each connection point is set to v4.25 as shown in the figure. V3. v2. V
Let it be l.

In this configuration, as can be inferred from the above explanation,
Voltage v1. V2. ■3. Timer one hour T corresponding to V4
are respectively T□ and T2. T3. T4, and the rotation angle θ of each sliding terminal of the variable resistor 27, 28, 29 is θ2□, θ28. If θ29 is set, the characteristics shown in FIG. 7 can be obtained immediately.

That is, in this embodiment, the timer one time period T preset by each variable resistor can be set in different time zones.

In this embodiment, if the relationship between each variable resistor and the fixed resistor connected in parallel with it is selected so as to satisfy equation (1) where n=1, three variable resistors 27
．． This will greatly reduce the variation in the total resistance value of 28.29.

In this embodiment, it is of course possible to have a configuration without the variable resistor 28, and in this case, the variable resistor 27 is used to control the variable resistor 29 during the timer period T=T3 to T4.
can be preset between T1 and T4,
Either one of these switches is the selection switch 12 (in this case, 2
A contact point is fine).

FIG. 8 shows still another embodiment of the timer circuit according to the present invention.

FIG. 8 shows a charging circuit A, a time setting circuit B, and a selection switch 12, and the others are omitted because they have the same configuration as FIG. 1.

In the figure, 30 is a resistor, 31 is a diode, 32 is a resistor, 33 is a circuit correction resistor, 34 is a resistor, 35 is a transistor, and 36 is a capacitor, which constitute a charging circuit A.

This charging circuit A constitutes a constant current circuit that constantly charges the capacitor 36 with a constant current through the action of the transistor 35.

The diode 31 compensates for the temperature characteristics of the base-emitter voltage of the transistor 35, and the circuit correction resistor 33 changes the value of the constant current flowing through the transistor 35 to correct the timer T. That's what I'm trying to do.

In this charging circuit A, when the power switch 2 is turned on, the charging voltage eC of the capacitor 36 increases linearly with time.

Next, time setting circuit B is fixed resistor 37, 38° 39.4
0,41 and variable resistor 42. 43. 44 as shown in the figure.

Therefore, by selecting the voltages at the respective connection points of the variable resistor and the fixed resistor so as to be equal to the charging voltage eC at a predetermined time after turning on the power switch 2 in the charging circuit A, for example, the ninth The characteristics shown in the figure are obtained.

That is, the rotation angles of the variable resistors 42, 43, 44 are set to θ, 4□, θ43. Assuming θ44, the timer time T that can be preset by each is T5 to T6. T
6-T7. It becomes T5 to T8.

In this embodiment, the charging circuit A has a constant current and the capacitor 36
Since the charging voltage ec is proportional to time, the timer one hour for each rotation angle of the three variable resistors is linear, and the timer one hour scale for the rotation angle can be set at equal intervals.

That is, in this embodiment, the time setting circuit B is
The configuration is an application of the one shown in the figure, and in order to make the timer time T vary linearly with respect to the rotation angle θ of the variable resistor, the charging circuit A is configured using a constant current circuit.

Several embodiments have been described above; i) In the embodiments shown in FIGS. 1, 4, and 6, the charging circuit A using a constant current circuit as shown in FIG. 8 is also configured. It is clear that it can be done.

ii) In the embodiment, the time setting circuit B is capable of presetting three timer hours, but it can be configured to any number of timers, and the variation range of the timer hour T that can be preset is also as follows: By applying the embodiments, various possibilities become possible.

1ii) In time setting circuit B, in order to reduce the variation in the total resistance value of the variable resistor, generally, the total resistance value of the variable resistor is The total resistance value of the variable resistor and its tolerance for variation are determined so that the variation in the timer hour due to the variation in resistance value is equal to or less than the variation in the timer hour caused by variation in the resistance value of the fixed resistor. The value, the resistance value of the fixed resistor, and the permissible value of its variation may be appropriately selected.

The timer circuit according to the present invention has the following features: a) It is possible to preset a plurality of timer hours using a plurality of variable resistors, and the variation in the resistance value of the variable resistors is substantially reduced significantly, so that the entire circuit By correcting the characteristics in only one place, one hour of the timer can be given with high precision.

b) The variation characteristic of the timer hour with respect to the rotation angle of the variable resistor can be designed relatively easily and freely, and the variation characteristic suitable for practical situations can be obtained.

C) It has a simple configuration, and is excellent in terms of price and mass production.

It exhibits various effects such as, and is extremely useful in industrial production.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a timer circuit in one embodiment of the present invention, Fig. 2 is an explanatory diagram of the same operation, Fig. 3 is a characteristic diagram of the same, Fig. 4 is a circuit diagram of the same embodiment, and Fig. 5 is a characteristic diagram of the embodiment shown in Fig. 4, Fig. 6 is a circuit diagram of the embodiment at the same place, Fig. 7 is a characteristic diagram of the embodiment shown in Fig. 6, and Fig. 8 is a circuit diagram of the embodiment at the same place. , FIG. 9 is a characteristic diagram of the embodiment of FIG. 8. 1...DC power supply, A...Charging circuit, B
...... Time setting circuit, C... Voltage comparison circuit, D... Drive circuit, 2... Power switch, 5... Capacitor, 6, 7. 8 Fixed resistor, 9, 10, 11... Variable resistor, 12
...Selection switch, 13...Comparator, 17...Relay, 19,20,21...
... Center tap, θ ... Rotation angle, T
...Timer one hour.

Claims (1)

[Scope of Claims] 1. A DC power source, a charging circuit that causes a charging current to flow from the DC power source to charge a capacitor, and a plurality of fixed resistors connected in series to the DC power source, and At least two variable resistors are connected in parallel through two terminal terminals that give a total resistance value thereof, and the sliding terminals of the variable resistors do not change the resistance value between the respective two terminal terminals, a time setting circuit that outputs each set voltage, a selection switch that selects one of the set voltages, and a capacitor charging voltage of the charging circuit;
a voltage comparison circuit that compares the voltage with the set voltage selected by the selection switch and outputs a predetermined output according to the state thereof; In contrast, by selecting small resistance values and tolerance values for variations thereof of the fixed resistors connected in parallel with the variable resistor, the set voltage due to variations in the total resistance value of the variable resistors can be reduced. A timer circuit characterized in that it is configured to reduce variations in. 2. The timer circuit according to claim 1, wherein in the time setting circuit, at least two variable resistors are each connected in parallel to the same or different fixed resistors. 3. In the time setting circuit, the total resistance value of the variable resistor varies with respect to the variation in the set voltage that occurs when the resistance value of the fixed resistor connected in parallel with the variable resistor varies. 2. The timer circuit according to claim 1, wherein the timer circuit is selected such that variations in each of the set voltages that occur when the voltage is generated are smaller.