Optocoupler PC817 original spot 50000 long-term supply Shenzhen Meisixing Technology Co., Ltd.

What is the difference between the optocoupler PC817 and PC817B?

The popular distinction is that the gears are different, and the PC817 is divided into A, B, C, and D, which is called the current transfer ratio (CTR) in writing.

The PC817B series product is a new optocoupler that has surfaced recently and has attracted wide attention from insiders. Based on its advantages of small size, long life, non-contact, high reliability, and strong anti-interference ability, PC817B optocoupler has been widely used in voltage automatic gain loop and voltage regulator circuit, as well as optoelectronic test circuit and optical control circuit.

The function and principle of PC817 linear optocoupler

pc817 is a commonly used linear optical coupler. It is often used as a coupling device in various functional circuits that require more precision. It has the function of completely isolating the upper and lower circuits and does not affect each other.

What is the difference between the optocoupler PC817 and PC817B?

Main features of pc817:

1. Current transfer ratio (CTR: MIN. 50%_at IF=5mA, VCE=5V)

2. High isolation voltage: 5000V RMS

3. Compact dual in-line package, PC817 is a single-channel optocoupler, PC827 is a two-channel optocoupler, PC837 is a three-channel optocoupler, and PC847 is a four-channel optocoupler.

4. Linear optocoupler components.

PC817 schematic

When the input terminal is powered on, the light emitter emits light and irradiates on the light receiver. The light receiver is turned on after receiving the light, and the photocurrent is output from the output terminal, thus realizing the conversion of "electricity-optical-electricity".

Ordinary optocouplers can only transmit digital signals (switching signals), and are not suitable for transmitting analog signals. The linear optocoupler is a new type of optoelectronic isolation device, which can transmit continuously changing analog voltage or current signals, so that the corresponding optical signal will be generated with the change of the input signal, so that the degree of conduction of the phototransistor is also different. , the output voltage or current is also different.

The PC817 optocoupler can not only play a feedback role but also play an isolation role.

What is the difference between the optocoupler PC817 and PC817B?

Detection method of photocoupler PC817:

1. Use a multimeter to electrically block (Rx1 to RX1k blocks) to test whether the light-emitting diode inside pin 2 of the input port is good (the judgment method is the same as that of ordinary diodes), and determine its positive and negative poles.

2. Use the Rx1k block to measure the output terminal 3) 4) The forward and reverse resistances between the emitter and collector of the phototransistor inside the pin should be ∞. Otherwise it is damaged.

3. Take an electrolytic capacitor with a capacitance of 1000~3300pF (the larger the capacitance, the better the effect). Charge it with Rx1k gear. After charging, set the multimeter to Rx1k block, connect the black pen to pin 4 and the red pen to pin 3, and then use the charged capacitor to discharge pin 1.2 (positive pin port, negative pin 2)). At the moment of discharge, if the needle swings to the right quickly, and then returns to the leftmost ∞ (this phenomenon is determined by the discharge characteristics of the capacitor), it means that the photoelectric coupling characteristics between the input and output are good. Otherwise, the optocoupler has poor performance.

What is the difference between the optocoupler PC817 and PC817B?

PC817 test method

1. Forward voltage drop: feet 1 and 2 are loaded, If=20mA, use a multimeter to test the voltage drop of feet 1 and 2 Vf≤1.4V.

What is the difference between the optocoupler PC817 and PC817B?

2. Saturation voltage drop: 1, 2 feet with load If=20mA, 3, 4 feet with load Ic=1mA, use a multimeter to test the 3, 4 feet voltage drop Vce≤0.2V.

What is the difference between the optocoupler PC817 and PC817B?

3. Collector current Ic: 1, 2 feet are loaded, If=5mA, 3, 4 feet add Vce=5V, test Ic current.

What is the difference between the optocoupler PC817 and PC817B?

4. Current conversion ratio CTR: the same as the 3 collector current IC test method, 1, 2 feet are loaded, If=5mA, 3, 4 feet add Vce=5V, test Ic current.

CTR=Ic/If*100%.