Optical power measurement and display circuit

Abstract

The utility model discloses an optical power measurement and display circuit which is characterized by comprising a photodiode PIN, operational amplifiers YF1 to YF10, LEDs 1 to LED10, resistors R1 to R22, a capacitor C1, a capacitor C2, a capacitor C3, an inductor L, a direct-current power supply VCC1 and a direct-current power supply VCC2. The device can accurately measure and display the receiving optical power within the construction demand range of the optical receiver, and is simple in structure, convenient, visual, low in cost and easy to implement.

Description

Technical Field

[0001] The invention relates to the technical field of optical fiber communication and broadcast television network, and in particular to an optical power measurement and display circuit. Background Art

[0002] At present, the optical receiver power display circuit often uses a display light to display the optical receiver received power. Due to the insufficient measurement and display accuracy, it is impossible to provide accurate reference for construction technicians. Therefore, an optical power measurement and display circuit is designed, which can accurately measure and display the received optical power within the scope of the optical receiver construction requirements. It has a simple structure, is convenient and intuitive, has low cost, and is easy to implement. Summary of the invention

[0003] The purpose of the present invention is to solve the above problems and to design a simple, convenient and intuitive optical power measurement and display circuit, which can measure and display the received optical power of the receiver in the optical power range of -7dBm to +2dBm.

[0004] The technical solution adopted by the present invention to solve its technical problem is: an optical power measurement and display circuit, characterized in that it is composed of a photodiode PIN, operational amplifiers YF1 to YF10, LED1 to LED10, resistors R1 to R22, capacitors C1, C2, C3, inductor L, DC power supply VCC1, and DC power supply VCC2.

[0005] The photodiode PIN is an optical power receiving device and converts the received optical power into a radio frequency signal and a control voltage signal; the LED1 to LED10 are LED display lights; the operational amplifiers YF1 to YF10 and the resistors R1 to R21 form an optical power voltage parameter calculation circuit; the DC power supply VCC1 is the circuit power supply, and VCC2 is a 5V reference power supply.

[0006] The ports of the operational amplifiers YF1 to YF10 marked with a "-" sign are inverting input terminals, the ports marked with a "+" sign are non-inverting input terminals, and the ports without a sign are output terminals.

[0007] The positive electrode of the photodiode PIN, one end of the capacitor C1 and one end of the inductor L are connected in parallel, and the other end of the capacitor C1 is grounded; the other end of the inductor L is connected in parallel with the resistor R22 and one end of the capacitor C2, and the other end of the capacitor C2 is grounded; the other end of the resistor R22 is connected in parallel with C3 and the reverse input end of the operational amplifier YF1 to YF10, and the other end of the capacitor C3 is grounded; the resistors R21, R11, R12, R13, R14, R15, R16, R17, R18, R19 and R20 are connected in series in order of arrangement, the other end of the resistor R20 is grounded, and the other end of the resistor R21 is connected in series with the DC power supply VCC1; the same-direction input end of the operational amplifier YF1 is connected in parallel with the connection between the resistors R21 and R11; the same-direction input end of the operational amplifier YF2 is connected in parallel with The connection point of resistor R11 and resistor R12 is connected in parallel; the same-direction input terminal of the operational amplifier YF3 is connected in parallel with the connection point of resistor R12 and resistor R13; the same-direction input terminal of the operational amplifier YF4 is connected in parallel with the connection point of resistor R13 and resistor R14; the same-direction input terminal of the operational amplifier YF5 is connected in parallel with the connection point of resistor R14 and resistor R15; the same-direction input terminal of the operational amplifier YF6 is connected in parallel with the connection point of resistor R15 and resistor R16; the same-direction input terminal of the operational amplifier YF7 is connected in parallel with the connection point of resistor R16 and resistor R17; the same-direction input terminal of the operational amplifier YF8 is connected in parallel with the connection point of resistor R17 and resistor R18; the same-direction input terminal of the operational amplifier YF9 is connected in parallel with the connection point of resistor R18 and resistor R19; the same-direction input terminal of the operational amplifier YF10 is connected in parallel with the connection point of resistor R19 and resistor R20.

[0008] The output end of the operational amplifier YF1 is connected in series with the negative electrode of LED1, and the positive electrode of LED1 is connected in series with one end of the resistor R1; the output ends of the operational amplifiers YF2 to YF10 are respectively connected in series with the negative electrodes of LED2 to LED10, and the positive electrodes of LED2 to LED10 are respectively connected in series with one end of the resistors R2 to R10, and the connection method is the same as the connection method of the output end of the operational amplifier YF1, LED1, and resistor R1; the other ends of the resistors R1 to R10 are connected in parallel with the DC power supply VCC2.

[0009] The DC power supply VCC1 outputs a DC voltage higher than the reference voltage of the DC power supply VCC2; and the photodiode PIN is applied with a reverse bias voltage.

[0010] The beneficial effect of the present invention is that since the present invention adopts multiple groups of operational amplifiers, resistors and LEDs to form a measurement and display circuit, it can measure and display the continuous light incident power in the optical power range of -7dBm to +2dBm and display it by lighting and extinguishing the LED. It has a simple structure, is convenient and intuitive, has low cost and is easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the principle of one embodiment of the present invention. DETAILED DESCRIPTION

[0012] In order to make the purpose and technical solution of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and an embodiment. When no optical power signal is input to the photodiode PIN, the positive voltage of the photodiode PIN is zero, and the voltages of the reverse input terminals of the operational amplifier YF1 to the operational amplifier YF10 are all zero. The DC power supply VCC1 is input to the same-direction input terminals of the operational amplifier YF1, the operational amplifier YF2, the operational amplifier YF3, the operational amplifier YF4, the operational amplifier YF5, the operational amplifier YF6, the operational amplifier YF7, the operational amplifier YF8, the operational amplifier YF9, and the operational amplifier YF10 through the series resistor R21, the resistor R11, the resistor R12, the resistor R13, the resistor R14, the resistor R15, the resistor R16, the resistor R17, the resistor R18, and the resistor R19. The output terminal voltages of the operational amplifier YF1 to the operational amplifier YF10 are all higher than the reference voltage of the DC power supply VCC2, and the LED1 to the LED10 are all extinguished.

[0013] When an optical power signal is input into the photodiode PIN and is in the range of -7dBm to +2dBm, the positive voltage of the photodiode PIN is highest at +2dBm and lowest at -7dBm. At other optical power points, the positive voltage of the photodiode changes linearly between -7dBm and +2dBm. The positive voltage of the photodiode PIN enters the reverse input terminal of the op amp YF1 through the inductor L and the resistor R22 to the op amp YF10. Since resistors R21, R11, R12, R13, R14, R15, R16, R17, R18, R19, and R20 are connected in series in sequence, when the input optical power is -7dBm, LED10 is on and the other LEDs are off; when the input optical power is -6dBm, LED10 and LED9 are on and the other LEDs are off; when the input optical power is -5dBm, LED10, LED9, and LED8 are on and the other LEDs are off; when the input optical power is -4dBm, LED10, LED9, LED8, and LED7 are on and the other LEDs are off; when the input optical power is -3dBm, LED10, LED9, LED8, LED7, and LED6 are on and the other LEDs are off; when the input optical power is -2dBm, LED10, LED9, LED8, LED7, and LED6 are on and the other LEDs are off. 8. LED7, LED6 and LED5 are on, and the rest of the LEDs are off; when the input optical power is -1dBm, LED10, LED9, LED8, LED7, LED6, LED5 and LED4 are on, and the rest of the LEDs are off; when the input optical power is 0dBm, LED10, LED9, LED8, LED7, LED6, LED5, LED4 and LED3 are on, and the rest of the LEDs are off; when the input optical power is +1dBm, LED10, LED9, LED8, LED7, LED6, LED5, LED4, LED3 and LED2 are on, and the rest of the LEDs are off; when the input optical power is +2dBm, LED1 to LED10 are all on, thereby realizing the function of measuring the photodiode PIN input optical power parameters and using LED display in the optical power range of -7dBm to +2dBm.

[0014] The above technical solutions only reflect the preferred technical solutions of the present invention. Any changes that may be made to certain parts thereof by those skilled in the art all reflect the principles of the present invention and fall within the protection scope of the present invention.

Claims

1. An optical power measurement and display circuit, characterized in that: It consists of a photodiode PIN, operational amplifiers YF1 to YF10, LED1 to LED10, resistors R1 to R22, capacitors C1, C2, C3, an inductor L, a DC power supply VCC1, and a DC power supply VCC2.

2. The optical power measurement and display circuit according to claim 1, characterized in that: The photodiode PIN is an optical power receiving device and converts the received optical power into a radio frequency signal and a control voltage signal; the LED1 to LED10 are LED display lights; the operational amplifiers YF1 to YF10 and the resistors R1 to R21 form an optical power voltage parameter calculation circuit; the DC power supply VCC1 is the circuit power supply, and VCC2 is a 5V reference power supply.

3. The optical power measurement and display circuit according to claim 1, characterized in that: The positive electrode of the photodiode PIN, one end of the capacitor C1 and one end of the inductor L are connected in parallel, and the other end of the capacitor C1 is grounded; the other end of the inductor L is connected in parallel with the resistor R22 and one end of the capacitor C2, and the other end of the capacitor C2 is grounded; the other end of the resistor R22 is connected in parallel with C3 and the reverse input end of the operational amplifier YF1 to YF10, and the other end of the capacitor C3 is grounded; the resistors R21, R11, R12, R13, R14, R15, R16, R17, R18, R19 and R20 are connected in series in order of arrangement, the other end of the resistor R20 is grounded, and the other end of the resistor R21 is connected in series with the DC power supply VCC1; the same-direction input end of the operational amplifier YF1 is connected in parallel with the connection between the resistors R21 and R11; the same-direction input end of the operational amplifier YF2 is connected in parallel with The connection point of resistor R11 and resistor R12 is connected in parallel; the same-direction input terminal of the operational amplifier YF3 is connected in parallel with the connection point of resistor R12 and resistor R13; the same-direction input terminal of the operational amplifier YF4 is connected in parallel with the connection point of resistor R13 and resistor R14; the same-direction input terminal of the operational amplifier YF5 is connected in parallel with the connection point of resistor R14 and resistor R15; the same-direction input terminal of the operational amplifier YF6 is connected in parallel with the connection point of resistor R15 and resistor R16; the same-direction input terminal of the operational amplifier YF7 is connected in parallel with the connection point of resistor R16 and resistor R17; the same-direction input terminal of the operational amplifier YF8 is connected in parallel with the connection point of resistor R17 and resistor R18; the same-direction input terminal of the operational amplifier YF9 is connected in parallel with the connection point of resistor R18 and resistor R19; the same-direction input terminal of the operational amplifier YF10 is connected in parallel with the connection point of resistor R19 and resistor R20.

4. The optical power measurement and display circuit according to claim 1, characterized in that: The output end of the operational amplifier YF1 is connected in series with the negative electrode of LED1, and the positive electrode of LED1 is connected in series with one end of the resistor R1; the output ends of the operational amplifiers YF2 to YF10 are respectively connected in series with the negative electrodes of LED2 to LED10, and the positive electrodes of LED2 to LED10 are respectively connected in series with one end of the resistors R2 to R10, and the connection method is the same as the connection method of the output end of the operational amplifier YF1, LED1, and resistor R1; the other ends of the resistors R1 to R10 are connected in parallel with the DC power supply VCC2; the DC power supply VCC1 outputs a DC voltage higher than the reference voltage of the DC power supply VCC2; the photodiode PIN is applied with a reverse bias voltage.

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