JPH01116710A - Programmable power unit - Google Patents

Abstract

PURPOSE:To decrease labor for adjustment of a power unit output and to improve accuracy by receiving an instruction command including information such as a reference voltage value given from a load side, and making the output variable based on the command. CONSTITUTION:When a terminal 12 is activated, it sends an output reference voltage setting command 13 of a character column to a programmable power unit 11 to set a supply voltage at a reference value. When a one-chip CPU 17 receives the character column from an input port 22, the programmable power unit 11 calculates an output reference value 24, and outputs it through an output port 23. When a D/A converter 19 receives the output reference value 24, it generates and outputs a reference voltage setting signal 21. Next, an output voltage driving circuit 16 makes variable the base current of an output power transistor based on it, generates and outputs an output power unit 14, and to the terminal 12, the direct current power unit equivalent to the reference power unit voltage of the terminal itself is supplied. Thus, at the time of the adjustment of the power unit output, the output can be adjusted without labor, and accuracy is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power supply device, and more particularly to a programmable power supply whose output value can be varied in response to commands issued from the outside.

[Conventional technology]

Conventional power supplies include switching power supplies with improved voltage conversion efficiency and constant voltage power supplies that maintain a constant output voltage despite load fluctuations, and are used as built-in power supply units in electronic devices.

In addition, some devices with relatively large outputs are configured as independent power supplies.

By the way, when the conventional built-in power supply unit mentioned above is installed in an electronic device that is a load, the user can adjust the output by connecting a measuring instrument such as a tester to the output terminal of the power supply unit, table .

While watching the display, I moved the output adjustment volume so that the output matched the reference value of the load side power supply.

[Problem that the invention seeks to solve]

The conventional power output adjustment method described above requires a measuring device such as a tester to be connected, which requires time and effort.

In addition, since the user directly moved the output adjustment volume to adjust the output value, setting errors were likely to occur.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a power supply device that reduces the effort required for adjustment and improves its accuracy.

[Means for solving problems]

The programmable power supply device of the present invention receives an instruction command containing information such as a reference voltage value given from the load side, and changes the output based on this command.

As a result, the power output is adjusted between the load-side device and the programmable power supply without human intervention, which reduces the effort required for adjustment and improves its accuracy.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to Examples.

In this embodiment, a character display type terminal used as a communication terminal will be used as an example of a load-side device.

It goes without saying that the following explanation is equally applicable to other devices, such as computers and word processors, as long as they have a function of issuing so-called instruction commands. - FIG. 1 is a block diagram showing the configuration of a programmable power supply device in an embodiment of the present invention. First, each part in the figure will be explained. The programmable power supply device 11 receives an output reference voltage setting command 13 (output reference value setting command) sent from the terminal 12 on the load side, and generates an output power 14 based on this in accordance with the terminal 120 reference power supply voltage. It is composed of a command decoder 15 and an output voltage drive circuit 16.

The terminal 12 is a load of the programmable power supply 11, and transmits its own reference power supply voltage to the programmable power supply 11 by an output reference voltage setting command 13, thereby supplying an output power 14 that matches its own reference power supply voltage. It is something you receive. The command decoder 15 includes a one-chip CPU 17, a clock generator 18, and a D/A
It consists of a converter 19 and an output reference voltage setting command 13 sent from a terminal 12 on the load side.
The receiver receives this and generates a reference voltage setting signal 21 (reference value setting signal) based on this. One chip CPU1
7 is a general-purpose 8-bit one-chip CPLI having a 12-bit input port 22 and a 12-bit output port 23, which receives the output reference voltage setting command 13 sent from the terminal 12 and converts it into 12-bit binary data. A certain output reference value 24 is generated.

The clock generator 18 has two functions for the one-chip CPU 17.
This is a clock oscillation circuit that supplies a 5 MHz system clock 25. The D/A converter 19 converts the 12-bit output reference value 24 sent from the output port 23 of the one-chip CPU 17 into a reference voltage setting signal 21 as a full-scale voltage output of 0 to 5 volts.
This outputs the following. The output voltage drive circuit 16 (output drive circuit) is a drive circuit that receives the reference voltage setting signal 21 and supplies the output power 14 to the terminal 12 at a voltage value that matches the reference power supply voltage on the load side.

Next, the operation of the programmable power supply device will be explained based on this figure. In this embodiment, the range of the operating power supply voltage of the terminal 12 is 10 to 14 volts DC, and the reference power supply voltage is 12.0 volts. In addition, programmable power supply device 1
1 outputs the power as an output voltage at a voltage value within the range of the operating power supply voltage of the terminal 12, that is, a voltage value within the range of 10 to 14 volts DC.

Therefore, in this embodiment, when the programmable power supply device 11 is turned on, the terminal 12 receives 10 to 1 volts of DC current.
Terminal 12 is activated by supplying a power supply voltage in the range of 4 volts.

When activated, the terminal 12 sends an output reference voltage setting command 13 to the programmable power supply device 11 in order to set the power supply voltage to a reference value. The output reference voltage setting command 13 output from the terminal 12 is an ASCII character string, and in this case, since the reference power supply voltage is 12.0 volts, the character string "12.0■" is sent. In the programmable power supply device 11, the one-chip CPU 17 inputs the character string " from the input port 22.
12. OV'' is received, an output reference value 24 is calculated using the following conversion formula, and is outputted through the output port 23.

However, Vx indicates the numerical value part of the output reference voltage setting command 13, and vb indicates the output reference value 24 of 12-bit binary data.

Subsequently, the D/A converter 9 receives this output reference value 24, generates a reference voltage setting signal 21 according to the following conversion formula, and outputs it.

However, Rf indicates the reference voltage setting signal 21.

In this case, the value of vb is 2048 from equation (1), so R
f is 2.5 volts.

Next, the output voltage drive circuit 16 receives this reference voltage setting signal 21, varies the base current of the output power transistor based on it, and generates and outputs the output power 14 according to the voltage value according to the following conversion formula. .

R "Ov = 10 + (14-10)X--...
(3) However, ○V indicates the output power supply 14. In this case R
The value of f is 2.5 volts from equation (2), so ○V is 1
The voltage will be 2.0 volts.

As a result, the terminal 12 is supplied with a DC power of 12.0 volts, which is equal to its own reference power supply voltage, so that it operates stably.

〔Effect of the invention〕

The programmable power supply device described above receives an instruction command containing information such as a reference voltage value given from the load side, and changes the output based on this command. Thereby, when adjusting the power output, there is no need to connect a measuring device such as a tester, so the adjustment does not take much time, and since it can be done without human intervention, the accuracy of the adjustment can be improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining one embodiment of the present invention,
FIG. 2 is a block diagram showing the configuration of a programmable power supply device. 11...Programmable power supply device, 13...
... Output reference voltage setting command, 14... Output power supply, 15... Command decoder, 16... Output voltage drive circuit, 17...
...One-chip CPU. 21...Reference voltage setting signal, 24...Output reference value. Applicant: NEC Corporation Representative

Claims (1)

[Scope of Claims] A command decoder that outputs a reference value setting signal upon receiving an output reference value setting command, and an output drive circuit that resets the output to the reference value upon receiving the reference value setting signal. A programmable power supply device characterized by: