JPH0217343Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a check circuit for an electric circuit device such as a data recorder.

Conventional technology Checks the quality of the data recorder's power supply, servo circuit, erase function, recording/reproducing amplifier for each channel, etc.
Checking before use is already done.
This type of check is called a self-test or self-check, and after performing A/D conversion (analog-to-digital conversion) of the voltage corresponding to the content of the check, it is compared with data in the normal voltage range using a microprocessor, etc. It is done by certain things. By the way, general data recorders, for example, +15V, +
Since it has multiple power supply circuits such as 9.5V, +5V, +6V, -6V, etc., and has a multi-channel configuration, the number of check items increases, and the check circuit inevitably becomes complicated.

Purpose of the invention Therefore, the purpose of the present invention is to provide a simplified check circuit.

Structure of the Invention To achieve the above object, the present invention will be described with reference to the reference numerals in the drawings showing the embodiments. a plurality of voltage detection lines A, B, C, D, and E connected to the plurality of power supply circuits to respectively detect the voltages of the plurality of power supply circuits;
and the plurality of voltage detection lines A, B, C, D,
A plurality of resistors R ₁ , R ₂ , R ₃ , R ₄ , R ₅ each connected in series with E and given a predetermined weight, and the plurality of resistors R ₁ , R ₂ , R ₃ , R ₄ , _R5 , and a voltage corresponding to the sum of the currents flowing through each of the plurality of resistors _R1 , _R2 , _R3 , _R4 , and _R5 . Judgment for determining the quality of the plurality of power supply circuits based on a common resistor _Rz connected between the common output line F and the ground to obtain a voltage on the line F, and the magnitude of the voltage of the common output line F. circuit 22, and the weights of the plurality of resistors R ₁ , R ₂ , R ₃ , R ₄ , R ₅ are
When the power supply voltage of any one of the plurality of power supply circuits is out of the permissible range, the common output line F
The present invention relates to a check circuit of an electric circuit device characterized in that the voltage of the circuit is set to a value outside a predetermined range.

Effects of the invention According to the above invention, abnormalities in the power supply circuit can be detected based on the combination of a common resistance R _z and a plurality of weighted resistances R ₁ to R ₅ and the total current flowing through the common resistance R _z . judge. Therefore, it is not necessary to provide independent determination circuits for a plurality of power supply circuits, and the configuration of the check circuit can be simplified.

Embodiment Next, a data recorder having a check circuit according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

In FIG. 1, numeral 1 indicates the main body of the data recorder in principle, and it includes a recording input terminal 2, a recording circuit 3, a recording head 4, a reproduction head 5, a reproduction circuit 6, a reproduction output terminal 7, and an erasing circuit 8. , an erasing head 9, a magnetic tape 10, a pair of reels 11 and 12,
It includes a capstan 13, a pinch roller 14, a servo circuit 15, and the like. Note that the recording circuit 3 includes an A/D converter, a memory, an amplifier, etc., and the reproducing circuit 6 includes a memory, an A/D converter, an amplifier, etc. In addition, in order to operate each part, +15V, +9.5V, +5V, +
Includes 6V and -6V power supplies (not shown).

The self-check circuit of this data recorder 1 sequentially detects the outputs of a power supply voltage detection circuit 16, a servo voltage detection circuit 17, an erase current detection circuit 18, an amplifier output detection circuit 19, and each detection circuit 16 to 19. Input switch to select, i.e. multiplexer 2
0, an A/D converter 21 that converts the output of the multiplexer 20 from analog to digital, and an A/D converter 21 that converts the output of the multiplexer 20 from analog to digital.
It is comprised of a determination circuit 22 comprising a microprocessor for comparing the output of the D converter 21 with a reference to determine the acceptability of each check item, and a display 23 for displaying the results of the determination circuit 22.

The power supply voltage detection circuit 16 includes first to fifth voltage detection lines A, which are connected to each power supply circuit in order to detect a plurality of power supply voltages of the data recorder 1, respectively.
B, C, D, E, and first to fifth resistors R ₁ , R ₂ , R ₃ , R ₄ , R connected to these detection lines A to E, respectively, and given predetermined weights. ₅ and each resistor
It consists of a common output line F of R ₁ to _{R 5} and a resistor R _z connected between this common output line F and the ground. In this embodiment, the first detection line A is connected to the power supply circuit of the first voltage V ₁ (+15V), and the second, third, fourth and fifth detection lines B, C, D and E are the second voltage V ₂ (+
9.5V) power supply, a third voltage V ₃ (+5V) power supply,
The power supply of the fourth voltage V ₄ (+6V), the fifth voltage V ₅ (−
6V) power supply. Also, the first resistor R ₁ is 75 kΩ, the second resistor R ₂ is 30 kΩ, the third resistor R ₃ is 8.2 kΩ, the fourth resistor R ₄ is 12 kΩ, and the fifth resistor R ₅ is 16 kΩ. Output level setting Resistor _Rz is set to 1kΩ.

Now, if the currents I ₁ to I ₅ that flow to the ground through each of the resistors R ₁ to R ₅ and the combined current that flows to the resistor R _z are I, then V ₀ = R _z I I = I ₁ + I ₂ + I ₃ +I ₄ +I ₅ I ₁ =V ₁ −V ₀ /R ₁ , I ₂ =V ₂ −V ₀ /R ₂ , I ₃ =V ₃ −V ₀ /R ₃ , I ₄ =V ₄ −V ₀ /R ₄ , _I5 = _V5 - _V0 / _R5 , so the output voltage _V0 is expressed by the following equation.

V ₀ = (V ₁ /R ₁ +V ₂ /R ₂ +V ₃ /R ₃ +V ₄ /R ₄ +V ₅ /R ₅ ) /
(1/R _z +1/R ₁ +1/R ₂ +1/R ₃ +1/R ₄ +1/R ₅ )
When the output voltage V ₀ is determined when the voltages V ₁ to _{V 5} of each detection line A to E are standard values, V ₀ is approximately 0.952V. Therefore, in this embodiment, this output voltage V ₀ is input to the A/D converter 21 through the multiplexer 20, where it is converted into a digital signal and input to the determination circuit 22 composed of a microprocessor. It is digitally compared with the reference data of 0.9V and 1.0V written in advance in the memory built into the judgment circuit 22, and if the output voltage _V0 is within the range of 0.9 to 1.0V, a judgment output indicating that the power supply is good is displayed. It is sent to the device 23 and displayed. On the other hand, the output voltage V ₀
If the voltage is less than 0.9V or exceeds 1.0V, a power supply failure judgment output is sent to the display 23.

However, when the first voltage V ₁ fluctuates by -30%, the output voltage V ₀ becomes 0.90640V, and when the first voltage V 1 fluctuates by +30%, V ₀ becomes
1.01291V, when the second voltage V ₂ fluctuates by -20%, V ₀
is 0.90387V, when the third voltage V 3 changes by -10%, V ₀ is 1.00023V, when the third voltage V ₃ changes by -10%, V ₀ is 0.90566V, +
When the fourth voltage V ₄ changes by -15%, V ₀ becomes 0.89500 V. When the fourth voltage V ₄ changes by -15%, V 0 becomes 0.89500 V. When the fifth voltage V 4 changes by -15%, V ₀ becomes 1.00911 V. When the fifth voltage V ₅ changes by -15%, V 0 becomes 0.89500 V. V ₀ is 0.99484V, when it fluctuates by +15%, V ₀ becomes
It becomes 0.90926V. Therefore, the first voltage V ₁ is approximately −
Range of 30% to +30%, second voltage V ₂ approximately -20%
~ +20% range, the third voltage V ₃ is approximately -10% ~ +
10% range, the fourth voltage V ₄ is approximately -15% to +15%
If the fifth voltage _V5 changes beyond the range of -15% to +15%, a determination result of a power supply failure is obtained. Note that if the voltage of one power source increases and the voltage of the other power source decreases at the same time, cancellation may occur and the output voltage V ₀ may not change to deviate from 0.9 to 1.0V. However, since the probability that two power supply circuits become abnormal at the same time and the probability that abnormalities such as one voltage increasing and the other voltage decreasing simultaneously are extremely small, there is almost no problem in practice.

In this embodiment, the proportions of the normal ranges of the first to fifth voltages V ₁ to V ₅ are not all the same.
Although weights are attached to the fifth resistors R ₁ to R ₅ ,
The weights of the resistances R ₁ to R ₅ may be set so that the normal ranges are the same. Further, the weight may be changed depending on the degree of importance.

This data recorder has servo function, erase function,
It is also possible to check the amplification function, and these checks are also performed prior to use. That is, the voltages corresponding to these are selected by the multiplexer 20 and sent to the determination circuit 22 through the A/D converter 21, where they are compared with reference data stored in the memory to determine whether or not they are acceptable. Although only one channel of the data recorder is shown in FIG. 1, since the data recorder actually has a multi-channel configuration, each channel is checked.

The determination circuit 22 is, in principle, a reference circuit 2 consisting of a memory or the like that stores reference data as shown in FIG.
4, the reference data obtained from this reference circuit 24 and, for example, the output voltage sent from the A/D converter 21.
It consists of a comparison circuit 25 that compares data such as V 0 with data such as V ₀ .

As is clear from the above, according to this embodiment, it is possible to detect an abnormality in the power supply without providing a plurality of check circuits corresponding to the plurality of power supplies for obtaining the voltages _V1 to _V5 . Therefore, the configurations of the multiplexer 20 and the determination circuit 22 can be simplified. Furthermore, the software of the microprocessor constituting the determination circuit 22 can be simplified.

Modification The quality of the power supply voltage may be determined by analog comparison between the output voltage V ₀ and the reference voltage. Alternatively, the configuration may be such that the resistor _Rz is omitted, and the impedance at the latter stage of the output line F may be used. Also,
It is also applicable to FM recording data recorders or other electrical circuit devices. In addition, the multiplexer 20, A/D converter 21, and determination circuit 22 are replaced by a multiplexer included in the data recorder main body 1,
It may also be used as an A/D converter and a microprocessor.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a data recorder according to an embodiment of the present invention, and FIG. 2 is a block diagram showing the principle of the determination circuit of FIG. 1. 16...Power supply voltage detection circuit, 21...A/D converter, 22...Judgment circuit, 23...Display device, A~
E...Voltage detection line, F...Common output line,
R ₁ ~ R ₅ ... weighted resistance, V ₀ ... output voltage.

Claims (1)

[Claims for Utility Model Registration] A circuit for checking a plurality of power supply circuits of an electric circuit device having a plurality of power supply circuits for supplying different voltages, the circuit for detecting the voltage of each of the plurality of power supply circuits. a plurality of voltage detection lines A, B, C, D, and E, each of which is connected to the plurality of power supply circuits; and a plurality of voltage detection lines A, B, C, D, and E.
a plurality of resistors R ₁ , R ₂ , R ₃ , R ₄ , R ₅ each connected in series with a predetermined weight; and a plurality of resistors R ₁ , R ₂ , R ₃ , R ₄ , A voltage corresponding to the sum of the currents flowing through the common output line F commonly connected to the output terminal of R ₅ and the plurality of resistors R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ is connected to the common output line F. a common resistor _Rz connected between the common output line F and the ground to obtain a voltage of F; and a determination circuit that determines the quality of the plurality of power supply circuits based on the magnitude of the voltage of the common output line F. 2
2, and the plurality of resistors R ₁ , R ₂ , R ₃ , R ₄ ,
The weight of _R5 is set such that when the power supply voltage of any one of the plurality of power supply circuits falls outside the permissible range, the voltage of the common output line F becomes a value outside a predetermined range. A check circuit for an electric circuit device characterized by: