JPS6041305A - Overload detecting circuit - Google Patents

Abstract

PURPOSE:To simplify the constitution of a circuit by detecting whether the input signal and the output signal of a driver circuit coincide with each other or not and outputting an overload signal on a basis of the detection result. CONSTITUTION:An input signal S1 is applied to an inverting amplifier (driver) 1 and an exclusive OR gate 5 of an overload detecting circuit 3. An output signal S2 amplified by the amplifier 1 is inverted by an inverter 4 and is applied to the other input of the gate 5. It is detected whether the input signal S1 and the output signal S2 coincide with each other or not by the detecting circuit 3; and if they do not coincide with each other, a load 2 is judged to be normal, and a load signal SE is not outputted. If they coincide with each other, the load signal SE is outputted; and thus, the constitution of the overload detecting circuit is simplfied.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an overload detection circuit that detects pressure when the load of a driver (intensifier, etc.) becomes overloaded.

When the door is overloaded, the driver is usually damaged, and if left unattended, it can cause unexpected problems such as fire. Therefore, overload detection circuits are very important in various devices. By the way, all conventional overload detection circuits have complicated structures, are expensive, and are stiff, which makes them difficult to employ, especially in fields such as automobiles where cost reduction is strongly required.

SUMMARY OF THE INVENTION Therefore, the present invention provides an overload detection circuit which has an extremely simple configuration and can be manufactured at low cost. Based on overload signal? It consists of an output circuit.

Embodiments of the present invention will now be described with reference to the drawings. Figure 1 is a diagram showing the configuration of the tth embodiment of this invention. In the diagram, reference numeral 1 indicates an inverting amplifier (driver), and 2 indicates the inverting amplifier 1.

The load 8 is an overload detection circuit according to the present invention. The overload detection circuit 8 has an inverter 4 whose input terminal is connected to the output terminal of the inverting amplifier 1, a first input terminal connected to the output terminal of the inverter 4, and a λ-th input terminal connected to the inverting amplifier 1.
It consists of exclusive OR gates (hereinafter abbreviated as y, Hx, and oR) 5 connected to the 0 input terminal, respectively, and
An overload signal 5R (H level signal) is output from the output terminal of X and OR5.

Next, the operation of the above circuit will be explained. First, a case where load 2 is normal will be explained.

When the input signal SI to the inverting amplifier 1 is at L level, the output signal S2 of the amplifier 1 is at H level, the load 2 is driven, and the output signal S of the inverter 4 is at L level. On the other hand, when the signal S1 is at the H level, the signal S2 is at the L level, the load 2 is not driven, and the signal S3 is at the H level.

In this way, if load 2 is normal, ff1X・OR5
No. 1. The signal supplied to the second input terminal is the input signal S
, and match regardless of the level of the input signal S+, therefore, EX , O
The output signal of R5 becomes L level, and the overload signal Sg<r
+level] is never output.

Next, when load 2 becomes overloaded, input signal S1 goes low.
When the signal S is at the high level, the signal S does not go to the high level but goes to the low level. As a result, an H level signal is supplied to the first input terminal of IIXx/OR5, an L level signal is supplied to the second input terminal, and E
An overload signal (H level) is output from XOR5.

If they do not match (signals S and S3 match), it is assumed that load 2 is normal and the overload signal 8x is not output, and if they match (signal S1
and S do not match), an overload signal 8w is output.

Figure 2 shows the second QJ embodiment ('J Fu5+2) of this invention.
The circuit shown in this section is different from the one shown in FIG. 1 in that a non-inverting amplifier 7 (driver) is used as the amplifier for driving the load 2, Buffer amplifier 8 instead of inverter 4 in the diagram
is used. In the circuit shown in this figure, when the load 2 is normal, the input signal S1 is at H level and L level.
In any case of level 11. X,,OR5
No. 1. The signals at the second input terminal match, so EX-
Output No. 18 of OR5 becomes L level, and overload signal Sw
(H level/L/) is never output. On the other hand, when the load 2 is in an overload state, when the input signal 8m is at the H level I7), the signal S2 does not go to the H level but goes to the L level. As a result, an L level signal is supplied to the first input terminal of EX/OR5, an H level signal is supplied to the second input terminal, and E
An overload signal 5R (H level) is output from the XOR5.

Similarly, in the circuit shown in Figure 2, the overload detection circuit 8 also checks whether the signals S1 and S2 match.

In the case of this circuit, the overload signal SEA is output when the two do not match.

As explained above, according to the present invention, it is detected whether or not the driver's manual input signal and the output signal match, and the overload signal is output based on this detection result.
The number of grooves is extremely small, and therefore it can be manufactured at low cost, and is particularly suitable for use in the field of VC where automatic conduction costs are required to be reduced.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 respectively show the first part of this invention. This is a circuit diagram of the second embodiment ◇ l... Inverting amplifier (driver), 2...
・Load, 3... Overload detection circuit, 4...
・Inverter, 5...°°・Exclusive OR gate, 7...Non-inverting amplifier (triver), 8.
...Buffer amplifier. Applicant: Fujikura Kame Line Co., Ltd. Oki Electric Industry Co., Ltd. ~1-J

Claims (1)

[Claims] In an overload detection circuit that detects when a load driven by a driver enters an excessive AM state, does the human power signal of the driver υ match the output signal of the driver? An overload detection circuit consisting of a circuit that detects an overload and outputs an overload signal sound based on the detection result.