JPS62283715A - Load control circuit apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Industrial Application Field The present invention relates to a circuit device for electrically controlling a load having an inductive reactance component as defined in the generic concept of claim 1. .

Conventional known technology and its problems This type of circuit device is described, for example, in West German Patent Application Publication No. 201.
It is known from the publication No. 3012.

Such loads with an inductive component are, for example, electromagnets or electromagnetic valves. In controlling this type of solenoid valve, the voltage applied to the solenoid valve is decisive for the suction time. For example, when a solenoid valve is used in an automobile, the on-board power supply voltage is subject to strong fluctuations.

Therefore, in such applications, the circuit may be modified to allow the solenoid valve to operate more quickly despite the voltage limitations, or to allow the design of the solenoid valve to be changed for the same switching time. is important. This applies to other loads as well.

, Structure of the Invention Such an improvement is achieved by the structure described in the characterizing part of claim 1. Other developments of the invention and advantageous uses thereof are described in the subclaims. Further advantages are clear from the description based on the figures below.

Embodiment In FIG. 1, reference numeral 1 indicates one power supply terminal of a power source used (for example, an on-board power supply), and reference numeral 2 indicates a solenoid valve. Solenoid valve 2
The emitter-collector section of the power transistor T2 and the electrically connected measuring resistor are connected in series.

The power transistor T2 forms a so-called Darlington circuit with the P-type transistor T1. The solenoid valve 2 is operated by controlling the transistor T1 with a switching signal applied to its base. Control is provided in this example by a signal E applied to terminal 6, which activates a control comparator output, which in turn controls the conduction of power transistor T2 via control amplifier 5 and transistor T1. The rise of the current flowing through the solenoid valve 2 takes place, for example, in accordance with the curve 20 in FIG. 2a. Measuring resistor 3, control: I The comparator 4 and the control amplifier 5 are such that when a predetermined operating current through the solenoid valve 2 is reached, the control 2o is interrupted for such a short time that the solenoid valve 2 is held in the suction state.

According to the invention, the power terminal 1 and the power transistor T2
Further, between the base of (or the emitter of T1) and the emitter of transistor T3,
-! ! L translation IR large collection 7 reha right man IITFi maki h- has been inserted. To control this transistor, inverting elements 8 and 9, bistable element 1o and AND gate 11
is provided.

The application of the control signal E to the terminal 6 causes a switching of the bistable element 10 via the inverting element 8, so that a signal is delivered to the Q output (see signal changes in FIGS. 2 and 2C).

By means of the inverting element 9 the signal is also passed to the second of the AND gate 11.
It is also applied to the input side of the transistor T3 to control the transistor T3.

This causes a considerably larger current to flow in the base of the transistor 20 than in a normal Darlington circuit. This current is limited by resistor 7. Therefore, the voltage at the collector of transistor T2 is as follows.

U↑2=Ucg 5atl −1−Ig2°RM As a result, transistor T2 reaches saturation. However, the saturation voltage as a function of base and collector currents is considerably lower than in the standard Darlington case. In FIG. 2a, the variation of the current IMV flowing through the solenoid valve 2 is shown by a curve 21. It can be seen that the current rise is larger than usual and the reachable final value is also higher (at PL). The solenoid valve thereby also switches earlier.

When the current value E#"-P3 is reached (which is detected by the converter 4), the control of the transistor T1 from the control amplifier 5 is first interrupted for a predetermined time, but
However, the output signal of the control controller ξ regulator also resets the bistable element 10, thereby causing the transistor T
3 is made inactive. At the same time, the solenoid valve 2 is no longer controlled, and the voltage of the solenoid valve gradually drops (P3
(see subsequent curves). However, before the solenoid valve 2 is restored, new control is performed via the control circuit. Since bistable element 10 can only be reset by a newly arriving E signal, transistor T3 remains switched off.

In other words, the transistor T3 always operates only when control of the solenoid valve 2 is started.

In the embodiment of FIG. 3, sections 1' to 11' and TI' to 73' correspond to the corresponding sections 1 to 11 and T1 to T3 in FIG. switchable between two comparison thresholds;
5' is a control clip-flop, and the solenoid valve 2 has three switching positions.

However, in this case a second control circuit for the transistor T3' is also provided, which is constituted by the terminals 6" to 11'. Both control circuits are connected via an OR gate 30 to the transistor T3'. The signals E and A applied to the terminals σ and A bring the solenoid valve 2' into the active position.

This is achieved by interrupting the rise of the current at the Me current value by the controllers 3', 5'. This is shown in Figure 4, where the solenoid valve current is increased by the E signal and then maintained at an average value (0 to 6 m5ec) by the controllers 3' to 5'. When the A signal occurs, the current increases further and then (approximately 14m5e
(c onwards) It is shown that the control once again keeps it constant on average. It can also be seen from this figure that T3 operates only during the rising phase due to the 0 signal (OR gate 30). The change marked with a dashed line indicates the rise without the effect of T3. Clock control operates as follows. When the current flowing through the resistor 3' reaches a predetermined value at the input side 6', the converter l
signal is applied to control flip-flop 5' and clip-flops 1σ and 1σ. The control flip-flop 5' is reset and ξ via the clock input side.
is applied, so that the current flows again through the measuring resistor 3'
Transistors T1 and T2 are cut off until the current flows through the transistors T1 and T2.

Having T3 cut off each time by reaching the desired current has the advantage that the tramp only loses power if the star function is used. For the same reason, it is also conceivable that the trans-nostar T3 is activated only when a more rapid rise in current is particularly required, since the on-board power supply voltage may momentarily become too low.

Effects of the Invention According to the present invention, by using the third transistor T3, the current rise characteristics can be improved, the voltage applied to the load can be quickly controlled, and power loss is also small.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a first embodiment of the present invention, FIG. 2 is a diagram for explaining FIG. 1, FIG. 3 is a circuit diagram of a second embodiment of the present invention, and FIG. It is a line diagram provided for explanation of a figure. l, 1'...Power terminal, 2,2'...Solenoid valve, 3,
3'...Measuring resistance, 4, 4°...Control converter/ξ regulator, 5...Control amplifier, 6, 6', σ...Terminal, 7, 7'...Limiting resistor, 8 , 8', 8', 9
,9', (7...inversion element, 10°1σ, 1σ・
...Bistable element, 11, 11', 11"...AND gate, 5...Control flip-flop, 3o...
...OR gate 2, name of the invention load control circuit device 3, relation to the amendment needle case Patent applicant 4, agent February 24, 1988 (Shipping date) As shown in the attached sheet

Claims (1)

[Claims] 1. An inductive circuit comprising a Darlington circuit comprising a driver transistor T1 and a downstream power transistor T2, with a load connected between the collectors of both transistors and one pole of the working voltage. In a circuit device for electrically controlling a load having a reactive component, an emitter-collector of a third transistor (T3) is connected between the same pole (1) of the power supply used and the base of a downstream power transistor (T2). A section is inserted, and this transistor (T3
) starts at the same time as the input connection of the load (2) via its base and for at least some time the downstream transistor (T
2) A load control circuit device characterized in that it can be switched to energization in order to supply a large current to the base of item 2). 2. The load control circuit device according to claim 1, wherein the third transistor (T3) is inserted in series with the limiting resistor (7). 3. When the current flowing through the electromagnet (2) representing the load resistance reaches a predetermined amount of operating current, the power transistor (T2)
The load control circuit device according to claim 1 or 2, which is used in a control circuit whose energization is momentarily interrupted by a controller (3, 4, 5). 4. Load control circuit arrangement according to claim 3, wherein as soon as the operating current is first reached, the third transistor (T3) is made inoperable until a new disconnection of the electromagnet (2). 5. When the current flowing through the electromagnet (2), which represents a load resistance and is controllable in two operating positions, reaches two predetermined different operating current values, based on two different control signals (E, A), the power transistor (T2) is used in a control circuit whose control is momentarily interrupted by the controller (3', 4', 5'), and the third transistor (T3 3. Load control circuit arrangement according to claim 1, wherein the load control circuit arrangement (1) is deactivated and is only activated again when a new control signal (E, A) occurs. 6. According to any one of claims 3 to 5, the third transistor is activated only when the operating voltage drops below a predetermined value. load control circuit device.