Hi,
I want to connect an analog Optocoupler (e.g. a phototransistor or a photodarlington), to isolate a high voltage AC from my TTL circuit. I want this optocoupler to give me a proportional output signal, 0-5V (active mode), as variable high voltage is applied to optocoupler's LED.
I understand how a 4-pin optocoupler (2 pins for Diode, and 2 pins for transistor's collector and emitter, no base pin) works.
But what do you do about those 6-pin optocouplers (e.g. 4n32, 4n25) where you have a base pin?
What is the purpose of the base pin in a phototransistor, considering the input signal is provided by the LED?
It's been a while since I worked with transistors in active mode, sou could you tell me which configuration would be best for my application? (e.g. common emitter; common collector; are +ve,-ve power supplies needed when attached to collector and emitter respectively?; etc.)
Any information is welcomed.
Thanks
I want to connect an analog Optocoupler (e.g. a phototransistor or a photodarlington), to isolate a high voltage AC from my TTL circuit. I want this optocoupler to give me a proportional output signal, 0-5V (active mode), as variable high voltage is applied to optocoupler's LED.
I understand how a 4-pin optocoupler (2 pins for Diode, and 2 pins for transistor's collector and emitter, no base pin) works.
But what do you do about those 6-pin optocouplers (e.g. 4n32, 4n25) where you have a base pin?
What is the purpose of the base pin in a phototransistor, considering the input signal is provided by the LED?
It's been a while since I worked with transistors in active mode, sou could you tell me which configuration would be best for my application? (e.g. common emitter; common collector; are +ve,-ve power supplies needed when attached to collector and emitter respectively?; etc.)
Any information is welcomed.
Thanks